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Molecules, Volume 18, Issue 1 (January 2013), Pages 1-1336

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Open AccessArticle The Feedback Regulation of PI3K-miR-19a, and MAPK-miR-23b/27b in Endothelial Cells under Shear Stress
Molecules 2013, 18(1), 1-13; doi:10.3390/molecules18010001
Received: 16 November 2012 / Revised: 12 December 2012 / Accepted: 14 December 2012 / Published: 20 December 2012
Cited by 13 | PDF Full-text (370 KB) | Supplementary Files
Abstract
Mechanical stimulation regulates endothelial cell (EC) functions through the modulation of signaling networks and gene expression. Our recent studies have identified that shear stress regulation of microRNAs (miRs)-19a, 23b and 27b, led to the modulation of EC proliferation. However, the underlying molecular [...] Read more.
Mechanical stimulation regulates endothelial cell (EC) functions through the modulation of signaling networks and gene expression. Our recent studies have identified that shear stress regulation of microRNAs (miRs)-19a, 23b and 27b, led to the modulation of EC proliferation. However, the underlying molecular mechanisms by which shear stress regulates these miRs have not been explored. Previous studies showed that shear stress activates multiple signaling pathways, including phosphatidylinositol 3 kinase (PI3K) and mitogen-activated protein kinase (MAPK). In this work we demonstrate that inhibition of the PI3K pathway attenuated the shear-induced miR-19a, and inhibition of the MAPK pathway attenuated miR-23b, 27b. The knockdown of miR-19a using antagomir-19a oligonucleotide (AM19a) decreased the shear-induced PI3K activation; whereas AM-23b, 27b reduced the shear-induced MAPK activation. Furthermore, the overexpression of miR-19a overrode the suppressive effects of PI3K inhibitors on shear-induced PI3K activation; the overexpression of miR-23b, 27b had similar effects on ERK activations, but had little effect on P38 and JNK activation. Our findings suggest a positive feedback loop whereby PI3K and MAPK mediate the shear regulation of miR expression, which in turn modulates the shear-regulated PI3K/MAPK signaling events in ECs. Full article
Open AccessArticle An N-Linked Bidentate Phosphoramidite Ligand (N-Me-BIPAM) for Rhodium-Catalyzed Asymmetric 1,4-Addition of Arylboronic Acids to α,β-Unsaturated Ketones
Molecules 2013, 18(1), 14-26; doi:10.3390/molecules18010014
Received: 30 November 2012 / Revised: 14 December 2012 / Accepted: 17 December 2012 / Published: 20 December 2012
Cited by 26 | PDF Full-text (354 KB)
Abstract
A new bidentate phosphoramidite (N-Me-BIPAM) based on Shibasaki’s N-linked BINOL was synthesized. This ligand appears to be highly effective for rhodium-catalyzed asymmetric conjugated addition of arylboronic acids to α,β-unsaturated enones. The reaction of ortho-substituted arylboronic acid with acyclic [...] Read more.
A new bidentate phosphoramidite (N-Me-BIPAM) based on Shibasaki’s N-linked BINOL was synthesized. This ligand appears to be highly effective for rhodium-catalyzed asymmetric conjugated addition of arylboronic acids to α,β-unsaturated enones. The reaction of ortho-substituted arylboronic acid with acyclic and cyclic enones provides the corresponding products in good yields and enantioselectivities. Full article
(This article belongs to the Special Issue Organoboron Chemistry)
Open AccessArticle Tripolyphosphate Cross-Linked Macromolecular Composites for the Growth of Shape- and Size-Controlled Apatites
Molecules 2013, 18(1), 27-40; doi:10.3390/molecules18010027
Received: 8 November 2012 / Revised: 26 November 2012 / Accepted: 10 December 2012 / Published: 20 December 2012
Cited by 6 | PDF Full-text (1048 KB)
Abstract
Bioactive composites that enable the formation of calcium phosphates have received increased attention over the last decade, in the development of osteoconductive biomaterials for orthopaedic applications. In this work, tripolyphosphate (TPP)-cross-linked chitosan/gelatin composites (TPP-CG) were prepared for the growth of shape- and [...] Read more.
Bioactive composites that enable the formation of calcium phosphates have received increased attention over the last decade, in the development of osteoconductive biomaterials for orthopaedic applications. In this work, tripolyphosphate (TPP)-cross-linked chitosan/gelatin composites (TPP-CG) were prepared for the growth of shape- and size-controlled calcium phosphates on/in the composites. The mineralization pattern of the composites, after soaking in the Ca(OH)2 aqueous solution, clearly demonstrated oriented, needle-like nanocrystallites of calcium phosphates in the matrix with especially high Ca/P molar ratio (3.98) as detected by energy dispersive X-ray spectroscopy (EDX) analysis. Subsequent to mineralization in a simulated body fluid (SBF), the mineralized composites showed micro-scaled spherical aggregates deposited on the surface and granule-like nanocrystallites grew in the matrix. The Ca/P molar ratio (1.72) and X-ray diffraction pattern of the nanocrystallites grown in the composites were similar to those of hydroxyapatite (HAp). Osteoblastic differentiation of ROS cells cultured on the mineralized composites allowed an enhanced expression of the chosen osteogenic marker (alkaline phosphatase, ALPase). These results indicated that the composites mineralized with micro- and nano-scaled calcium phosphates with various structural features make them attractive for bone tissue engineering applications. Full article
(This article belongs to the Special Issue Chitins and Chitosans)
Open AccessArticle Anti-inflammatory Lignans from the Fruits of Acanthopanax sessiliflorus
Molecules 2013, 18(1), 41-49; doi:10.3390/molecules18010041
Received: 24 August 2012 / Revised: 10 December 2012 / Accepted: 14 December 2012 / Published: 21 December 2012
Cited by 11 | PDF Full-text (285 KB) | Supplementary Files
Abstract
A new lignan, named acanthosessilin A (1), as well as eight known lignan and lignan glycosides 2-9 were isolated from an ethanolic extract of Acanthopanax sessiliflorus fruits. The chemical structures were determined by spectroscopic methods, including HR-EIMS, 1D [...] Read more.
A new lignan, named acanthosessilin A (1), as well as eight known lignan and lignan glycosides 2-9 were isolated from an ethanolic extract of Acanthopanax sessiliflorus fruits. The chemical structures were determined by spectroscopic methods, including HR-EIMS, 1D NMR (1H, 13C, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC, NOESY), and IR spectroscopy. All isolated compounds were tested for the ability to inhibit LPS-induced nitric oxide production in RAW264.7 macrophages. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Synthesis of New Optically Active 2-Pyrrolidinones
Molecules 2013, 18(1), 50-73; doi:10.3390/molecules18010050
Received: 6 November 2012 / Revised: 5 December 2012 / Accepted: 12 December 2012 / Published: 21 December 2012
Cited by 2 | PDF Full-text (360 KB)
Abstract
A new class of optically active 2-pyrrolidinones was synthesized, starting from S-pyroglutamic acid, a well known natural chiral synthon. The synthetic design followed led to the insertion of various substituents at positions 1 and 5 of the 2-pyrrolidinone ring, including the [...] Read more.
A new class of optically active 2-pyrrolidinones was synthesized, starting from S-pyroglutamic acid, a well known natural chiral synthon. The synthetic design followed led to the insertion of various substituents at positions 1 and 5 of the 2-pyrrolidinone ring, including the imidazole moiety. Some of them possess two or three stereogenic centers, the configuration of which was retained under the mild conditions used. The new compounds also carry an imidazole moiety, which, along with the 2-pyrrolidinone template, may prove pivotal to several biological processes. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Brønsted Acidic Ionic Liquid Accelerated Halogenation of Organic Compounds with N-Halosuccinimides (NXS)
Molecules 2013, 18(1), 74-96; doi:10.3390/molecules18010074
Received: 15 November 2012 / Revised: 6 December 2012 / Accepted: 11 December 2012 / Published: 21 December 2012
Cited by 11 | PDF Full-text (591 KB)
Abstract
The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into [...] Read more.
The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into α-halo and α,α-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of α-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO3H)][OTf] ionic liquid (IL-A) was successfully reused eight times in a representative monohalogenation reaction with no noticeable decrease in efficiency. An effective halogenation scale-up in this IL is also presented. The reactivity trend and the observed chemo- and regioselectiivities point to an ET process in these IL-promoted halofunctionalization reactions. Full article
(This article belongs to the Section Organic Synthesis)
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Open AccessArticle Synthesis and Promising in Vitro Antiproliferative Activity of Sulfones of a 5-Nitrothiazole Series
Molecules 2013, 18(1), 97-113; doi:10.3390/molecules18010097
Received: 6 November 2012 / Revised: 14 November 2012 / Accepted: 12 December 2012 / Published: 21 December 2012
Cited by 2 | PDF Full-text (268 KB)
Abstract
The synthesis in water of new sulfone derivatives under microwave irradiation is described. This eco-friendly process leads to the expected products in good yields by reaction of various substituted sulfinates (commercially available or obtained by reduction of the corresponding sulfonyl chlorides) with [...] Read more.
The synthesis in water of new sulfone derivatives under microwave irradiation is described. This eco-friendly process leads to the expected products in good yields by reaction of various substituted sulfinates (commercially available or obtained by reduction of the corresponding sulfonyl chlorides) with 4-chloromethyl-2-methyl-5-nitro-1,3-thiazole. In order to evaluate the antiproliferative effect of these compounds, several sulfone derivatives are also dichlorinated on the Cα next to the sulfonyl group. An evaluation on different cancer cell lines reveals promising selective in vitro antiproliferative activity toward HepG2 human cell lines by dihydrogenated sulfones, suggesting further research should be to explore their anticancer potential in the treatment of liver cancer. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Chemical Constituents of Three Allium Species from Romania
Molecules 2013, 18(1), 114-127; doi:10.3390/molecules18010114
Received: 26 November 2012 / Revised: 16 December 2012 / Accepted: 19 December 2012 / Published: 21 December 2012
Cited by 22 | PDF Full-text (479 KB)
Abstract
The aim of this work was to study the chemical composition of Allium obliquum L., A. senescens L. subsp. montanum (Fries) Holub, and A. schoenoprasum L. subsp. schoenoprasum. Sulphur-containing compounds analysis was performed by an LC-MS method, the identification and [...] Read more.
The aim of this work was to study the chemical composition of Allium obliquum L., A. senescens L. subsp. montanum (Fries) Holub, and A. schoenoprasum L. subsp. schoenoprasum. Sulphur-containing compounds analysis was performed by an LC-MS method, the identification and quantification of polyphenolic compounds through a HPLC-UV-MS method, and the presence of five sterols was simultaneously assessed by HPLC-MS-MS. Alliin was identified only in A. obliquum and A. senescens subsp. montanum extracts, whilst allicin was present in all extracts, with higher amounts in A. schoenoprasum and A. obliquum. The pattern of phenol carboxylic acids shows the presence of p-coumaric and ferulic acids in all species. Isoquercitrin was identified in A. obliquum and A. schoenoprasum, and rutin in A. senescens subsp. montanum and A. schoenoprasum. Luteolin and apigenin were identified only in A. obliquum. All three species contain glycosides of kaempferol and quercetol. β-Sitosterol and campesterol were identified in all species. The results obtained showed significant differences in the composition of the three Allium species. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
Open AccessArticle Cytotoxic and Antioxidant Compoundsfrom the Stem Bark of Goniothalamus tapisoides Mat Salleh
Molecules 2013, 18(1), 128-139; doi:10.3390/molecules18010128
Received: 8 November 2012 / Revised: 16 December 2012 / Accepted: 19 December 2012 / Published: 21 December 2012
Cited by 5 | PDF Full-text (309 KB)
Abstract
Eleven compounds:goniomicin A (1), goniomicin B (2), goniomicin C (3), goniomicin D (4), tapisoidin (5), goniothalamin (6), 9-deoxygoniopypyrone (7), pterodondiol (8), liriodenine (9), benzamide [...] Read more.
Eleven compounds:goniomicin A (1), goniomicin B (2), goniomicin C (3), goniomicin D (4), tapisoidin (5), goniothalamin (6), 9-deoxygoniopypyrone (7), pterodondiol (8), liriodenine (9), benzamide (10) and cinnamic acid (11), were isolated from the stem bark of Goniothalamus tapisoides. All compounds were identified by spectroscopic analysis and, for known compounds, by comparison with published data. Goniothalamin (6) exhibited mild cytotoxic activity towards a colon cancer cell line (HT-29), with an IC50value of 64.17 ± 5.60 µM. Goniomicin B (2) give the highest antioxidant activity in the DPPH assay among all compounds tested, with an IC50 of 0.207 µM. Full article
Open AccessArticle Inhibitory Evaluation of Sulfonamide Chalcones on β-Secretase and Acylcholinesterase
Molecules 2013, 18(1), 140-153; doi:10.3390/molecules18010140
Received: 19 November 2012 / Revised: 16 December 2012 / Accepted: 18 December 2012 / Published: 21 December 2012
Cited by 10 | PDF Full-text (308 KB) | Supplementary Files
Abstract
The action of β-secretase (BACE1) is strongly correlated with the onset of Alzheimer’s disease (AD). Aminochalcone derivatives were examined for their ability to inhibit BACE1. Parent aminochalcones showed two digit micromolar IC50s against BACE1. Potency was enhanced 10-fold or more [...] Read more.
The action of β-secretase (BACE1) is strongly correlated with the onset of Alzheimer’s disease (AD). Aminochalcone derivatives were examined for their ability to inhibit BACE1. Parent aminochalcones showed two digit micromolar IC50s against BACE1. Potency was enhanced 10-fold or more by introducing benzenesulfonyl derivatives to the amino group: 1 (IC50 = 48.2 μM) versus 4a (IC50 = 1.44 μM) and 2 (IC50 = 17.7 μM) versus 5a (IC50 = 0.21 μM). The activity was significantly influenced by position and number of hydroxyl groups on the chalcone B-ring: 3,4-dihydroxy 5a (IC50 = 0.21 μM) > 4-hydroxy 4a (IC50 = 1.44 μM) > 2,4-dihydroxy 6 (IC50 = 3.60 μM) > 2,5-dihydroxy 7 (IC50 = 16.87 μM) > des hydroxy 4b (IC50 = 168.7 μM). Lineweaver-Burk and Dixon plots and their secondary replots indicate that compound 5a was a mixed inhibitor with reversible and time-dependent behavior. Potent BACE1 inhibitors 4a,c,f, 5ac showed moderate inhibition against two other enzymes implicated in AD pathogenesis, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with IC50s ranging between 56.1 ~ 95.8 μM and 19.5 ~ 79.0 μM, respectively. Full article
Open AccessArticle Novel Conformationally Constrained Analogues of Agomelatine as New Melatoninergic Ligands
Molecules 2013, 18(1), 154-166; doi:10.3390/molecules18010154
Received: 29 October 2012 / Revised: 14 December 2012 / Accepted: 18 December 2012 / Published: 24 December 2012
Cited by 2 | PDF Full-text (226 KB)
Abstract
Novel conformationally restricted analogues of agomelatine were synthesized and pharmacologically evaluated at MT1 and MT2 melatoninergic receptors. Replacement of the N-acetyl side chain of agomelatine by oxathiadiazole-2-oxide (compound 3), oxadiazole-5(4H)-one (compound 4), tetrazole (compound 5 [...] Read more.
Novel conformationally restricted analogues of agomelatine were synthesized and pharmacologically evaluated at MT1 and MT2 melatoninergic receptors. Replacement of the N-acetyl side chain of agomelatine by oxathiadiazole-2-oxide (compound 3), oxadiazole-5(4H)-one (compound 4), tetrazole (compound 5), oxazolidinone (compound 7a), pyrrolidinone (compound 7b), imidazolidinedione (compound 12), thiazole (compounds 13 and 14) and isoxazole moieties (compound 15) led to a decrease of the melatoninergic binding affinities, particularly at MT1. Compounds 7a and 7b exhibiting nanomolar affinity towards the MT2 receptors subtypes have shown the most interesting pharmacological results of this series with the appearance of a weak MT2-selectivity. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Sulfation and Enhanced Antioxidant Capacity of an Exopolysaccharide Produced by the Medicinal Fungus Cordyceps sinensis
Molecules 2013, 18(1), 167-177; doi:10.3390/molecules18010167
Received: 22 November 2012 / Revised: 10 December 2012 / Accepted: 19 December 2012 / Published: 24 December 2012
Cited by 11 | PDF Full-text (215 KB)
Abstract
EPS-1 was an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis (Cs-HK1). In the present study, EPS-1 was sulfated with chlorosulfonic acid (CSA)-pyridine (Pyr) at different volume ratios, yielding four sulfated derivatives, SEPS-1A, B, C and D, with different degrees of substitution [...] Read more.
EPS-1 was an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis (Cs-HK1). In the present study, EPS-1 was sulfated with chlorosulfonic acid (CSA)-pyridine (Pyr) at different volume ratios, yielding four sulfated derivatives, SEPS-1A, B, C and D, with different degrees of substitution (DS: 0.25–1.38) and molecular weights (17.1–4.1 kDa). The sulfation of EPS-1 occurred most frequently at the C-6 hydroxyl groups due to their higher reactivity. In aqueous solution, the native EPS-1 formed random coils or aggregated networks, but the sulfated derivatives formed single helices. The antioxidant activities of the sulfated EPS-1 derivatives for scavenging hydroxyl radicals (•OH) and 2,2-azinobis-3-ehtylbenzothiazolin-6-sulfonic acid radicals (ABTS•+) were significantly increased with increasing DS and decreasing molecular weight (MW). Sulfation has thus been shown to be an effective and favorable strategy for improving the physico-chemical properties and bioactivities of fungal polysaccharides. Full article
(This article belongs to the Special Issue Antioxidants 2012)
Open AccessArticle Stability and Antioxidant Activity of Semi-synthetic Derivatives of 4-Nerolidylcatechol
Molecules 2013, 18(1), 178-189; doi:10.3390/molecules18010178
Received: 26 October 2012 / Revised: 16 November 2012 / Accepted: 20 November 2012 / Published: 24 December 2012
Cited by 7 | PDF Full-text (294 KB)
Abstract
4-nerolidylcatechol (4-NC) is an unstable natural product that exhibits important antioxidant, anti-inflammatory and other properties. It is readily obtainable on a multi-gram scale through straightforward solvent extraction of the roots of cultivated Piper peltatum or P. umbellatum, followed by column chromatography [...] Read more.
4-nerolidylcatechol (4-NC) is an unstable natural product that exhibits important antioxidant, anti-inflammatory and other properties. It is readily obtainable on a multi-gram scale through straightforward solvent extraction of the roots of cultivated Piper peltatum or P. umbellatum, followed by column chromatography on the resulting extract. Semi-synthetic derivatives of 4-NC with one or two substituent groups (methyl, acetyl, benzyl, benzoyl) on the O atoms have been introduced that have increased stability compared to 4-NC and significant in vitro inhibitory activity against the human malaria parasite Plasmodium falciparum. Antioxidant and anti-inflammatory properties may be important for the antiplasmodial mode of action of 4-NC derivatives. Thus, we decided to investigate the antioxidant properties, cytotoxicity and stability of 4-NC derivatives as a means to explore the potential utility of these compounds. 4-NC showed high antioxidant activity in the DPPH and ABTS assays and in 3T3-L1 cells (mouse embryonic fibroblast), however 4-NC was more cytotoxic (IC50 = 31.4 µM) and more unstable than its derivatives and lost more than 80% of its antioxidant activity upon storage in solution at −20 °C for 30 days. DMSO solutions of mono-O-substituted derivatives of 4-NC exhibited antioxidant activity and radical scavenging activity in the DPPH and ABTS assays that was comparable to that of BHA and BHT. In the cell-based antioxidant model, most DMSO solutions of derivatives of 4-NC were less active on day 1 than 4-NC, quercetin and BHA and more active antioxidants than BHT. After storage for 30 days at −20 °C, DMSO solutions of most of the derivatives of 4-NC were more stable and exhibited more antioxidant activity than 4-NC, quercetin and BHA and exhibited comparable antioxidant activity to BHT. These findings point to the potential of derivatives of 4-NC as antioxidant compounds. Full article
(This article belongs to the Special Issue Antioxidants 2012)
Open AccessArticle Synthesis and Characterization of Carboxymethyl Chitosan Nanogels for Swelling Studies and Antimicrobial Activity
Molecules 2013, 18(1), 190-203; doi:10.3390/molecules18010190
Received: 12 October 2012 / Revised: 13 December 2012 / Accepted: 18 December 2012 / Published: 24 December 2012
Cited by 17 | PDF Full-text (714 KB)
Abstract
Nanogels of a binary system of carboxymethyl chitosan (CMCh) and poly- (vinyl alcohol) PVA, were successfully synthesized by a novel in situ process. They were also characterized by various analytical tools like Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and [...] Read more.
Nanogels of a binary system of carboxymethyl chitosan (CMCh) and poly- (vinyl alcohol) PVA, were successfully synthesized by a novel in situ process. They were also characterized by various analytical tools like Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XRD). They were studied for their unique swelling properties in water and different pH solutions. They were also investigated for their great ability to capture or isolate bacteria and fungi from aquatic environments. Full article
Open AccessArticle Supramolecular Ring Structures of 7-Methylguanine: A Computational Study of Its Self-assembly and Anion Binding
Molecules 2013, 18(1), 225-235; doi:10.3390/molecules18010225
Received: 1 November 2012 / Revised: 14 December 2012 / Accepted: 21 December 2012 / Published: 27 December 2012
Cited by 1 | PDF Full-text (382 KB)
Abstract
The density functional theory calculations of 7-methylguanine clusters revealed that stable ring assemblies can be formed with or without anions in the center position and hexameric clusters are the most stable and most planar ones. The coordination of anions (Cl, [...] Read more.
The density functional theory calculations of 7-methylguanine clusters revealed that stable ring assemblies can be formed with or without anions in the center position and hexameric clusters are the most stable and most planar ones. The coordination of anions (Cl, Br, NO3) stabilizes and thus favors the formation of planar aggregates. We believe that the predicted planar structures stabilized by anions are good models for self-assembly structures formed at solid-liquid or solid-gas interfaces. Comparing the bonding and average H-bond energy to reference ribbon calculations we pointed out the presence of the previously introduced cooperativity effect in circular supramolecular structures of 7-methylguanine. Full article
(This article belongs to the Special Issue Nucleic Acid Analogs)
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Open AccessArticle 4862F, a New Inhibitor of HIV-1 Protease, from the Culture of Streptomyces I03A-04862
Molecules 2013, 18(1), 236-243; doi:10.3390/molecules18010236
Received: 31 October 2012 / Revised: 14 December 2012 / Accepted: 18 December 2012 / Published: 27 December 2012
Cited by 1 | PDF Full-text (245 KB)
Abstract
We have isolated an extraordinary pentapeptide, called 4862F, from the culture broth of Streptomyces albosporus I03A-04862 by Diaion HP-20 macroporous adsorbent resin column, ODS-A and Sephadex LH-20 chromatography, followed by preparative HPLC. This peptide shows inhibitory activity against HIV-1 protease. The structure [...] Read more.
We have isolated an extraordinary pentapeptide, called 4862F, from the culture broth of Streptomyces albosporus I03A-04862 by Diaion HP-20 macroporous adsorbent resin column, ODS-A and Sephadex LH-20 chromatography, followed by preparative HPLC. This peptide shows inhibitory activity against HIV-1 protease. The structure was elucidated by spectroscopic approaches, including ESI-MS and various NMR methods. Absolute configuration of the amino acid residues in 4862F was defined using Marfey’s method, and the structure was identified as N,N,N-(trimethylated)-Tyr-L-Leu-L-Val-L-Leu-(dehydrated)-His. The peptide 4862F displays inhibitory activity against HIV-1 protease, with IC50 values of 15.26 nM, using a fluorescence-based assay. Full article
(This article belongs to the Section Natural Products)
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Open AccessArticle Characterization of Flavonoids and Naphthopyranones in Methanol Extracts of Paepalanthus chiquitensis Herzog by HPLC-ESI-IT-MSn and Their Mutagenic Activity
Molecules 2013, 18(1), 244-262; doi:10.3390/molecules18010244
Received: 28 November 2012 / Revised: 11 December 2012 / Accepted: 18 December 2012 / Published: 27 December 2012
Cited by 5 | PDF Full-text (427 KB)
Abstract
A HPLC-ESI-IT-MSn method, based on high-performance liquid chromatography coupled to electrospray negative ionization multistage ion trap mass spectrometry, was developed for rapid identification of 24 flavonoid and naphthopyranone compounds. The methanol extracts of the capitulae and scapes of P. chiquitensis exhibited [...] Read more.
A HPLC-ESI-IT-MSn method, based on high-performance liquid chromatography coupled to electrospray negative ionization multistage ion trap mass spectrometry, was developed for rapid identification of 24 flavonoid and naphthopyranone compounds. The methanol extracts of the capitulae and scapes of P. chiquitensis exhibited mutagenic activity in the Salmonella/microsome assay, against strain TA97a. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Proteomic and Functional Analyses Reveal MAPK1 Regulates Milk Protein Synthesis
Molecules 2013, 18(1), 263-275; doi:10.3390/molecules18010263
Received: 18 October 2012 / Revised: 11 December 2012 / Accepted: 18 December 2012 / Published: 27 December 2012
Cited by 13 | PDF Full-text (502 KB)
Abstract
L-Lysine (L-Lys) is an essential amino acid that plays fundamental roles in protein synthesis. Many nuclear phosphorylated proteins such as Stat5 and mTOR regulate milk protein synthesis. However, the details of milk protein synthesis control at the transcript and translational levels are [...] Read more.
L-Lysine (L-Lys) is an essential amino acid that plays fundamental roles in protein synthesis. Many nuclear phosphorylated proteins such as Stat5 and mTOR regulate milk protein synthesis. However, the details of milk protein synthesis control at the transcript and translational levels are not well known. In this current study, a two-dimensional gel electrophoresis (2-DE)/MS-based proteomic technology was used to identify phosphoproteins responsible for milk protein synthesis in dairy cow mammary epithelial cells (DCMECs). The effect of L-Lys on DCMECs was analyzed by CASY technology and reversed phase high performance liquid chromatography (RP-HPLC). The results showed that cell proliferation ability and β-casein expression were enhanced in DCMECs treated with L-Lys. By phosphoproteomics analysis, six proteins, including MAPK1, were identified up-expressed in DCMECs treated with 1.2 mM L-Lys for 24 h, and were verified by quantitative real-time PCR (qRT-PCR) and western blot. Overexpression and siRNA inhibition of MAPK1 experiments showed that MAPK1 upregulated milk protein synthesis through Stat5 and mTOR pathway. These findings that MAPK1 involves in regulation of milk synthesis shed new insights for understanding the mechanisms of milk protein synthesis. Full article
Open AccessArticle Unexpected Behavior of Enaminones: Interesting New Routes to 1,6-Naphthyridines, 2-Oxopyrrolidines and Pyrano[4,3,2-de][1,6]naphthyridines
Molecules 2013, 18(1), 276-286; doi:10.3390/molecules18010276
Received: 16 October 2012 / Revised: 22 October 2012 / Accepted: 26 November 2012 / Published: 27 December 2012
Cited by 3 | PDF Full-text (350 KB)
Abstract
Reaction of enaminones 1ad with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9ad. On the other hand, 2-aminopyrano[4,3,2-de] [1,6]naphthyridine-3-carbonitriles 20ac,e were the only obtained [...] Read more.
Reaction of enaminones 1ad with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9ad. On the other hand, 2-aminopyrano[4,3,2-de] [1,6]naphthyridine-3-carbonitriles 20ac,e were the only obtained products from the reactions of 1ad with 2 in the presence of AcOH/NaOAc, while 1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone 21 under the same condition. The reaction of 2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid ethyl ester 15B. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessCommunication Anthraquinones of the Roots of Pentas micrantha
Molecules 2013, 18(1), 311-321; doi:10.3390/molecules18010311
Received: 4 December 2012 / Revised: 19 December 2012 / Accepted: 20 December 2012 / Published: 27 December 2012
Cited by 7 | PDF Full-text (310 KB) | Supplementary Files
Abstract
Pentas micrantha is used in the East African indigenous medicine to treat malaria. In the first investigation of this plant, the crude methanol root extract showed moderate antiplasmodial activity against the W2- (3.37 μg/mL) and D6-strains (4.00 μg/mL) of Plasmodium falciparum and [...] Read more.
Pentas micrantha is used in the East African indigenous medicine to treat malaria. In the first investigation of this plant, the crude methanol root extract showed moderate antiplasmodial activity against the W2- (3.37 μg/mL) and D6-strains (4.00 μg/mL) of Plasmodium falciparum and low cytotoxicity (>450 μg/mL, MCF-7 cell line). Chromatographic separation of the extract yielded nine anthraquinones, of which 5,6-dihydroxylucidin-11-O-methyl ether is new. Isolation of a munjistin derivative from the genus Pentas is reported here for the first time. The isolated constituents were identified by NMR and mass spectrometric techniques and showed low antiplasmodial activities. Full article
(This article belongs to the Special Issue Plant Natural Products against Human Parasites)
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Open AccessArticle Schizandrin Protects Primary Rat Cortical Cell Cultures from Glutamate-Induced Apoptosis by Inhibiting Activation of the MAPK Family and the Mitochondria Dependent Pathway
Molecules 2013, 18(1), 354-372; doi:10.3390/molecules18010354
Received: 8 November 2012 / Revised: 21 December 2012 / Accepted: 24 December 2012 / Published: 27 December 2012
Cited by 18 | PDF Full-text (410 KB)
Abstract
Glutamate-induced excitotoxicity has been implicated in a variety of neuronal degenerative disorders. In the present study, we investigated the possible neuroprotective effects of schizandrin against apoptosis of primary cultured rat cortical cells induced by glutamate. Glutamate (10 μM) administered for 24 h [...] Read more.
Glutamate-induced excitotoxicity has been implicated in a variety of neuronal degenerative disorders. In the present study, we investigated the possible neuroprotective effects of schizandrin against apoptosis of primary cultured rat cortical cells induced by glutamate. Glutamate (10 μM) administered for 24 h decreased the expression of Bcl-2 and Bcl-XL protein, whereas increased the expression of Bax, Bak, apoptosis inducing factor (AIF), endonuclease G (Nodo G) and endoplasmic reticulum (ER) stress of caspase-12. Pretreatment with schizandrin (100 μM) before glutamate treatment increased the Bcl-XL and Bcl-2 expression and decreased Bax, Bak, AIF, Nodo G and caspase-12 compared with those only treated with glutamate. Furthermore, glutamate-induced phosphorylation of JNK, p38 and ERK mitogen-activated protein kinases (MAPK), and these effects were attenuated by schizandrin (100 μM) treatment. These results suggest that schizandrin possesses the neuroprotective effects. The molecular mechanisms of schizandrin against glutamate-induced apoptosis may involve the regulation of Bcl-2 family proteins expression, and ER stress through blocking the activation of JNK, ERK and p38 MAPK. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Two New Phragmalin-Type Limonoids from Chukrasia tabularis var. velutina
Molecules 2013, 18(1), 373-380; doi:10.3390/molecules18010373
Received: 23 October 2012 / Revised: 7 December 2012 / Accepted: 19 December 2012 / Published: 27 December 2012
Cited by 4 | PDF Full-text (289 KB)
Abstract
Two new phragmalin-type limonoids with different structural skeletons, chuktabrin K (1) and tabulalin J (2), were isolated from the stem barks of Chukrasia tabularis var. velutina in the course of our ongoing research work in this area. Compound [...] Read more.
Two new phragmalin-type limonoids with different structural skeletons, chuktabrin K (1) and tabulalin J (2), were isolated from the stem barks of Chukrasia tabularis var. velutina in the course of our ongoing research work in this area. Compound 1 was a 16-norphragmalin with an enolic alkyl appendage at C-15, and the carbonate moiety in 1 was also rare in natural organic molecules. The basic skeleton of compound 2 was a D-ring-opened phragmalin. Their structures were elucidated on HR-ESI-MS, 1H and 13C-NMR, HSQC, HMBC, and ROESY experiments. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Effect of Rain-Shelter Cultivation of Vitis vinifera cv. Cabernet Gernischet on the Phenolic Profile of Berry Skins and the Incidence of Grape Diseases
Molecules 2013, 18(1), 381-397; doi:10.3390/molecules18010381
Received: 20 November 2012 / Revised: 21 December 2012 / Accepted: 24 December 2012 / Published: 27 December 2012
Cited by 7 | PDF Full-text (287 KB)
Abstract
Rain-shelter cultivation is an effective cultural method to prevent rainfall damage during grape harvest and widely applied in the Chinese rainy regions. In this study we investigated the effect of rain-shelter cultivation on grape diseases and phenolic composition in the skins of [...] Read more.
Rain-shelter cultivation is an effective cultural method to prevent rainfall damage during grape harvest and widely applied in the Chinese rainy regions. In this study we investigated the effect of rain-shelter cultivation on grape diseases and phenolic composition in the skins of Vitis vinifera cv. Cabernet Gernischet grape berries through the comparison with open-field cultivation at two vintages (2010 and 2011). The results showed that rain-shelter cultivation reduced the incidence of grape diseases significantly and delayed the maturation of Cabernet Gernischet fruits. With regards to most of the phenolic compounds identified in this study, their content in grape samples under rain-shelter cultivation was decreased compared to those under open-field cultivation. However, rain-shelter cultivation stimulated the accumulation of dihydroquercetin-3-O-rhamnoside in grape skins during grape maturation. These were related with micrometeorological alterations in vineyards by using plastic covering under rain-shelter cultivation. It suggests the rain-shelter cultivation makes possible the cultivation of “Cabernet Gernischet” grapes in an organic production system, for providing a decrease in the incidence of diseases and the dependence on chemical pesticides in the grape and wine industry. Full article
(This article belongs to the Section Natural Products)
Open AccessCommunication Efficient Indium-Mediated Dehalogenation of Aromatics in Ionic Liquid Media
Molecules 2013, 18(1), 398-407; doi:10.3390/molecules18010398
Received: 21 November 2012 / Revised: 10 December 2012 / Accepted: 24 December 2012 / Published: 28 December 2012
Cited by 8 | PDF Full-text (238 KB)
Abstract An efficient indium-mediated dehalogenation reaction of haloaromatics and haloheteroaromatics in ionic liquids has been studied. This method is simple and effective in the presence of [bmim]Br. Furthermore, this methodology is environmentally friendly compared with conventional ones. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Response Surface Methodology Optimization of Fermentation Conditions for Rapid and Efficient Accumulation of Macrolactin A by Marine Bacillus amyloliquefaciens ESB-2
Molecules 2013, 18(1), 408-417; doi:10.3390/molecules18010408
Received: 20 November 2012 / Revised: 5 December 2012 / Accepted: 18 December 2012 / Published: 28 December 2012
Cited by 6 | PDF Full-text (497 KB)
Abstract
In the present work, an antibiotic-producing marine bacterium was isolated from a seawater sample collected from Yuhuan, Zhejiang, China, identified and named as Bacillus amyloliquefaciens ESB-2 on the basis of phenotypic characteristics and 16S rRNA gene sequencing. Response surface methodology was applied [...] Read more.
In the present work, an antibiotic-producing marine bacterium was isolated from a seawater sample collected from Yuhuan, Zhejiang, China, identified and named as Bacillus amyloliquefaciens ESB-2 on the basis of phenotypic characteristics and 16S rRNA gene sequencing. Response surface methodology was applied to optimize the fermentation conditions for rapid and efficient accumulation of macrolactin A, a pharmacologically important marine antibiotic. Eight fermentation conditions were examined for their significance on macrolactin A production using Plackett–Burman factorial design, where peptone, medium volume and temperature significantly improved production rate. Further optimization was carried out using Box-Behnken design of experiments to study the influence of process variables. The optimized fermentation condition for maximum production was peptone 14.8 mg/mL, yeast extract 1 mg/mL, FePO4 0.01 mg/mL, temperature 26.3 °C, initial pH value 6.0, medium volume 72.4%, rotation speed 150 r/min, inoculation 5% and fermented for 2 days. Under the optimized conditions, the concentration of macrolactin A reached 21.63 mg/L, representing a 2.4-fold increase compared to the original standard condition, which was also 17% higher than previous highest report of 18.5 mg/L and three times higher in terms of daily productivity. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle (3S)-1,2,3,4-Tetrahydro-β-carboline-3-carboxylic Acid from Cichorium endivia. L Induces Apoptosis of Human Colorectal Cancer HCT-8 Cells
Molecules 2013, 18(1), 418-429; doi:10.3390/molecules18010418
Received: 19 November 2012 / Revised: 13 December 2012 / Accepted: 17 December 2012 / Published: 28 December 2012
Cited by 7 | PDF Full-text (436 KB)
Abstract
Cichorium endivia. L, consumed either cooked or eaten raw in salads, is a popular kind of vegetable cultivated all around the World. Its components have been widely used in folk medicine in anti-inflammatory therapy. However, the anti-cancer activity of the components [...] Read more.
Cichorium endivia. L, consumed either cooked or eaten raw in salads, is a popular kind of vegetable cultivated all around the World. Its components have been widely used in folk medicine in anti-inflammatory therapy. However, the anti-cancer activity of the components has never been reported. In this study, (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (1), an amino acid isolated from C. endivia. L, was found for the first time to show cytotoxic activity in colorectal cancer cell line HCT-8. Compound 1 at concentrations of 0.5–4 μM induced apoptosis of HCT-8 cells in a dose-dependent manner. The compound 1-induced apoptosis in HCT-8 cells was accompanied by the loss of mitochondrial membrane potential, the activation of caspase-3, caspase-8 and caspase-9, the up-regulation of Bax and the down-regulation of Bcl-2. In addition, compound 1 suppressed the activation of NF-κB, which acts as an inhibitor of apoptosis. Taken together, these results suggested that compound 1 could significantly induce apoptosis of HCT-8 cells through the suppression of NF-κB signaling pathway, and thus can be considered as a potential candidate for developing chemotherapeutic drugs against cancer. Full article
Open AccessArticle Cross-Coupling Reaction with Lithium Methyltriolborate
Molecules 2013, 18(1), 430-439; doi:10.3390/molecules18010430
Received: 4 December 2012 / Revised: 21 December 2012 / Accepted: 27 December 2012 / Published: 28 December 2012
Cited by 3 | PDF Full-text (215 KB)
Abstract
We newly developed lithium methyltriolborate as an air-stable white solid that is convenient to handle. The good performance of this triolborate for metal-catalyzed bond-forming reactions was demonstrated in palladium-catalyzed cross-coupling reactions with haloarenes. Cross-coupling reaction of [MeB(OCH2)3CCH3 [...] Read more.
We newly developed lithium methyltriolborate as an air-stable white solid that is convenient to handle. The good performance of this triolborate for metal-catalyzed bond-forming reactions was demonstrated in palladium-catalyzed cross-coupling reactions with haloarenes. Cross-coupling reaction of [MeB(OCH2)3CCH3]Li with aryl halides occurred in the presence of Pd(OAc)2/RuPhos complex in refluxing MeOH/H2O and the absence of bases. Full article
(This article belongs to the Special Issue Suzuki Reaction)
Open AccessArticle Optimization of Shikonin Homogenate Extraction from Arnebia euchroma Using Response Surface Methodology
Molecules 2013, 18(1), 466-481; doi:10.3390/molecules18010466
Received: 12 November 2012 / Revised: 21 December 2012 / Accepted: 26 December 2012 / Published: 2 January 2013
Cited by 3 | PDF Full-text (1337 KB)
Abstract
An efficient homogenate extraction technique was employed for extracting shikonin from Arnebia euchroma. The homogenate extraction procedure was optimized and compared with other conventional extraction techniques. The proposed method gave the best result with the highest extraction efficiency in the shortest [...] Read more.
An efficient homogenate extraction technique was employed for extracting shikonin from Arnebia euchroma. The homogenate extraction procedure was optimized and compared with other conventional extraction techniques. The proposed method gave the best result with the highest extraction efficiency in the shortest extraction time. Based on single-factor experiments, a three-factor-three-level experimental design has been developed by Box-Behnken design. The optimal conditions were 78% ethanol as solvent, homogenate extraction time of 4.2 min, 10.3 liquid to solid ratio and two extraction cycles. Moreover, the proposed method was validated by stability, repeatability and recovery experiments. The developed homogenate extraction method provided a good alternative for the extraction of shikonin from A. euchroma. The results indicated that the proposed homogenate extraction was a convenient, rapid and efficient sample preparation technique and was environmental friendly. Furthermore, homogenate extraction has superiority in the extraction of thermally sensitive compounds from plant matrices. Full article
Open AccessArticle Antioxidant Properties of cis-Z,Z'-3a.7a',7a.3a'-Dihydroxy-ligustilide on Human Umbilical Vein Endothelial Cells in Vitro
Molecules 2013, 18(1), 520-534; doi:10.3390/molecules18010520
Received: 16 November 2012 / Revised: 14 December 2012 / Accepted: 18 December 2012 / Published: 2 January 2013
Cited by 6 | PDF Full-text (1230 KB)
Abstract
A new chemical component, cis-Z,Z'-3a.7a',7a.3a'-dihydroxyligustilide, was isolated from Angelica sinensis and its structure elucidated from its NMR and MS spectra and confirmed by X-ray single crystal diffraction analysis. We also explored the antioxidative properties of cis-Z,Z'-3a.7a',7a.3a'-dihydroxyligustilide [...] Read more.
A new chemical component, cis-Z,Z'-3a.7a',7a.3a'-dihydroxyligustilide, was isolated from Angelica sinensis and its structure elucidated from its NMR and MS spectra and confirmed by X-ray single crystal diffraction analysis. We also explored the antioxidative properties of cis-Z,Z'-3a.7a',7a.3a'-dihydroxyligustilide on human umbilical vein endothelial cells (HUVECs) against injuries induced by hydrogen peroxide (H2O2) using an MTT assay and flow cytometry analysis. In addition, the activities of superoxide dismutase (SOD), malondialdehyde (MDA), lactate dehydrogenase (LDH), nitric oxide (NO) and reactive oxygen species (ROS) were determined. We found that cis-Z,Z'-3a.7a',7a.3a'-dihydroxyligustilide increased the viability of HUVECs injured by H2O2 in a dose-dependent manner, reduced the apoptosis of HUVEC, and enhanced HUVEC proliferation. Our results demonstrated the remarkable in vitro antioxidative activities of this compound, indicating that it could be a potential antioxidant with protective effects against H2O2-induced HUVEC injuries. Full article
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Open AccessArticle Enaminonitriles in Heterocyclic Synthesis: A Route to 1,3-Diaryl-4-aminopyrazole Derivatives
Molecules 2013, 18(1), 535-544; doi:10.3390/molecules18010535
Received: 29 October 2012 / Revised: 15 November 2012 / Accepted: 24 December 2012 / Published: 2 January 2013
Cited by 5 | PDF Full-text (195 KB)
Abstract
Benzylcyanide and 4-nitrobenzylcyanide condensed with triethyl orthoformate and piperidine or morpholine to yield 2-aryl-2-piperidinyl or 2-morpholinylacrylonitriles. These coupled with aromatic diazonium salts to yield the 2-arylhydrazno-2-arylethane nitriles in good yields. The latter were converted into 4-aminopyrazoles in good yields using the Thorpe-Ziegler [...] Read more.
Benzylcyanide and 4-nitrobenzylcyanide condensed with triethyl orthoformate and piperidine or morpholine to yield 2-aryl-2-piperidinyl or 2-morpholinylacrylonitriles. These coupled with aromatic diazonium salts to yield the 2-arylhydrazno-2-arylethane nitriles in good yields. The latter were converted into 4-aminopyrazoles in good yields using the Thorpe-Ziegler cyclization. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Effects of Spray-Drying and Choice of Solid Carriers on Concentrations of Labrasol® and Transcutol® in Solid Self-Microemulsifying Drug Delivery Systems (SMEDDS)
Molecules 2013, 18(1), 545-560; doi:10.3390/molecules18010545
Received: 14 November 2012 / Revised: 25 November 2012 / Accepted: 25 December 2012 / Published: 2 January 2013
Cited by 11 | PDF Full-text (544 KB)
Abstract
Solid self-microemulsifying drug delivery systems (SMEDDS) have been used increasingly for improving the bioavailability of hydrophobic drugs. Labrasol® and Transcutol® are used widely as surfactant and solubilizer in the formulation of solid SMEDDS. We investigated the effects of spray-drying and [...] Read more.
Solid self-microemulsifying drug delivery systems (SMEDDS) have been used increasingly for improving the bioavailability of hydrophobic drugs. Labrasol® and Transcutol® are used widely as surfactant and solubilizer in the formulation of solid SMEDDS. We investigated the effects of spray-drying and the use of different solid carriers on concentrations of Labrasol® and Transcutol® in solid SMEDDS with scutellarin as the formulated drug. Liquid and gas chromatography tandem mass spectrometry (LC-MS and GC-MS) methods were developed for measuring low concentrations of Labrasol® and Transcutol®. In the preparation of solid SMEDDS, lactose, hydroxypropylmethyl cellulose (HPMC) and microcrystalline cellulose (MCC) were used as solid carriers. Judging from the retention ratios of Labrasol® and Transcutol®, the droplet size of solid SMEDDS increased after spray-drying of liquid SMEDDS, and concentrations of these excipients decreased after the solidifying procedure. In such reduction, Lactose and HPMC were found to preserve Labrasol® and Transcutol® better than MCC during spray-drying, and the resultant droplet sizes were smaller than that of MCC. Labrasol® and Transcutol® showed good thermal stability at 60 °C degree for 10 days. It can be concluded that spray-drying could increase the droplet size of solid SMEDDS and decreased the concentration of Labrasol® and Transcutol® therein, while water-soluble solid carriers could preserve Labrasol® and Transcutol® better than insoluble carriers in the solid SMEDDS. Full article
(This article belongs to the Special Issue Phytochemicals: Analytical and Medicinal Chemistry)
Open AccessArticle The Sonodegradation of Caffeic Acid under Ultrasound Treatment: Relation to Stability
Molecules 2013, 18(1), 561-573; doi:10.3390/molecules18010561
Received: 17 October 2012 / Revised: 16 December 2012 / Accepted: 19 December 2012 / Published: 4 January 2013
Cited by 3 | PDF Full-text (315 KB)
Abstract
The degradation of caffeic acid under ultrasound treatment in a model system was investigated. The type of solvent and temperature were important factors in determining the outcome of the degradation reactions. Liquid height, ultrasonic intensity and duty cycle only affected degradation rate, [...] Read more.
The degradation of caffeic acid under ultrasound treatment in a model system was investigated. The type of solvent and temperature were important factors in determining the outcome of the degradation reactions. Liquid height, ultrasonic intensity and duty cycle only affected degradation rate, but did not change the nature of the degradation. The degradation rate of caffeic acid decreased with increasing temperature. Degradation kinetics of caffeic acid under ultrasound fitted a zero-order reaction from −5 to 25 °C. Caffeic acid underwent decomposition and oligomerization reactions under ultrasound. The degradation products were tentatively identified by FT-IR and HPLC-UV-ESIMS to include the corresponding decarboxylation products and their dimers. Full article
Open AccessArticle Comparative Evaluation of Different Co-Antioxidants on the Photochemical- and Functional-Stability of Epigallocatechin-3-gallate in Topical Creams Exposed to Simulated Sunlight
Molecules 2013, 18(1), 574-587; doi:10.3390/molecules18010574
Received: 15 November 2012 / Revised: 19 December 2012 / Accepted: 28 December 2012 / Published: 4 January 2013
Cited by 12 | PDF Full-text (294 KB)
Abstract
The catechin (−)-epigallocatechin-3-gallate (EGCG) exhibits high antioxidant activity and it has been reported to provide protection of the skin against damage induced by solar UV radiation. However, EGCG is highly unstable under sunlight. The present study aimed to compare the effectiveness of [...] Read more.
The catechin (−)-epigallocatechin-3-gallate (EGCG) exhibits high antioxidant activity and it has been reported to provide protection of the skin against damage induced by solar UV radiation. However, EGCG is highly unstable under sunlight. The present study aimed to compare the effectiveness of the co-antioxidant agents vitamin E, butylated hydroxytoluene, vitamin C and a-lipoic acid for their potential to protect the catechin from photochemical degradation. Model creams (oil-in-water emulsions) containing EGCG (1%, w/w) alone or combined with equimolar concentrations of co-antioxidant were exposed to a solar simulator at an irradiance corresponding to natural sunlight. Photodegradation was evaluated by HPLC-UV and HPLC-ESI-MS/MS. Addition of the co-antioxidants vitamin C and a-lipoic acid to the formulation significantly reduced the light-induced decomposition of EGCG from 76.9 ± 4.6% to 20.4 ± 2.7% and 12.6 ± 1.6%, respectively. Conversely, butylated hydroxytoluene had no effect (EGCG loss, 78.1 ± 4.6%) and vitamin E enhanced the EGCG photolysis to 84.5 ± 3.4%. The functional stability of the catechin in the creams exposed to the solar simulator was also evaluated by measuring the in vitro antioxidant activity. Following irradiation, the reduction of the EGCG formulation antioxidant power was lower (21.8%) than the extent of degradation (76.9%), suggesting the formation of photoproducts with antioxidant properties. The influence of the examined co-antioxidants on the functional stability of the catechin under simulated sunlight paralleled that measured for the EGCG photodecomposition, a-lipoic acid exerting the greatest stabilising effect (antioxidant activity decrease, 1.4%). These results demonstrated that a-lipoic acid is an effective co-antioxidant agent for the stabilization of EGCG in dermatological products for skin photoprotection. Full article
(This article belongs to the Section Natural Products)
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Open AccessArticle Efficient Synthesis of a (Z)-3-Methyleneisoindolin-1-one Library Using Cu(OAc)2•H2O/DBU under Microwave Irradiation
Molecules 2013, 18(1), 654-665; doi:10.3390/molecules18010654
Received: 3 December 2012 / Revised: 21 December 2012 / Accepted: 27 December 2012 / Published: 4 January 2013
Cited by 9 | PDF Full-text (216 KB)
Abstract
Microwave-promoted efficient synthesis of a (Z)-3-methyleneisoindolin-1-one library from 2-bromobenzamides and terminal alkynes using Cu(OAc)2•H2O/DBU is described. Various benzamide substituents, ring substitutions, including heteroaryl, aryl acetylenes and aliphatic alkynes, could be applied to afford the desired products [...] Read more.
Microwave-promoted efficient synthesis of a (Z)-3-methyleneisoindolin-1-one library from 2-bromobenzamides and terminal alkynes using Cu(OAc)2•H2O/DBU is described. Various benzamide substituents, ring substitutions, including heteroaryl, aryl acetylenes and aliphatic alkynes, could be applied to afford the desired products in good to moderate yield with high stereoselectivity. It is noteworthy that DBU maybe play a dual role as not only the base, but also as a ligand for copper. The reaction is catalyzed by the complex of Cu(OAc)2•H2O and DBU without other additives. Full article
Open AccessArticle The Combination of Mitragynine and Morphine Prevents the Development of Morphine Tolerance in Mice
Molecules 2013, 18(1), 666-681; doi:10.3390/molecules18010666
Received: 17 October 2012 / Revised: 27 December 2012 / Accepted: 28 December 2012 / Published: 4 January 2013
Cited by 5 | PDF Full-text (266 KB)
Abstract
Mitragynine (MG) is the major active alkaloid found in Mitragyna speciosa Korth. In the present study, we investigated the enhancement of analgesic action of MG when combined with morphine and the effect of the combination on the development of tolerance towards morphine. [...] Read more.
Mitragynine (MG) is the major active alkaloid found in Mitragyna speciosa Korth. In the present study, we investigated the enhancement of analgesic action of MG when combined with morphine and the effect of the combination on the development of tolerance towards morphine. Mice were administered intraperitoneally with a dose of MG (15 and 25 mg/kg b.wt) combined with morphine (5 mg/kg b.wt) respectively for 9 days. The antinociceptive effect was evaluated by a hot plate test. The protein expression of cyclic adenosine monophosphate (cAMP) and cAMP response element binding (CREB) was analyzed by immunoblot. Toxicological parameters especially liver and kidney function tests were assessed after the combination treatment with MG and morphine. The concurrent administration of MG and morphine showed significant (p < 0.05) increase in latency time when compared to morphine alone group and the outstanding analgesic effects in the combination regimens were maintained until day 9. For the protein expression, there was a significant increment of cAMP and CREB levels (p < 0.05) in group treated with 5 mg/kg morphine but there was no significant change of these protein expressions when MG was combined with morphine. There was a significant changes in toxicological parameters of various treated groups. The combination treatment of MG and morphine effectively reduce the tolerance due to the chronic administration of morphine. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Diterpenoids with Anti-Inflammatory Activity from the Wood of Cunninghamia konishii
Molecules 2013, 18(1), 682-689; doi:10.3390/molecules18010682
Received: 11 December 2012 / Revised: 27 December 2012 / Accepted: 28 December 2012 / Published: 4 January 2013
Cited by 13 | PDF Full-text (252 KB)
Abstract
Two new diterpenoids, konishone (1) and 3b-hydroxy-5,6-dehydrosugiol (2), along with three known diterpenoids—hinokiol (3), sugiol (4), and 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial (5)—were isolated from the wood of Cunninghamia konishii. Compound 1 is a novel [...] Read more.
Two new diterpenoids, konishone (1) and 3b-hydroxy-5,6-dehydrosugiol (2), along with three known diterpenoids—hinokiol (3), sugiol (4), and 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial (5)—were isolated from the wood of Cunninghamia konishii. Compound 1 is a novel skeleton of the 7,20-dinorabietane-type diterpene. In addition, when RAW264.7 macrophages were treated with different concentrations of compounds 1, 3, and 5 together with LPS, a significant concentration-dependent inhibition of NO production was detected. The IC50 values for inhibition of nitrite production of compounds 1, 3, and 5 were about 9.8 ± 0.7, 7.9 ± 0.9, and 9.3 ± 1.3 μg/mL, respectively. This study presents the potential utilization of compounds 1, 3, and 5, as lead compounds for the development of anti-inflammatory drugs. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Curcumin Induces Cell Death and Restores Tamoxifen Sensitivity in the Antiestrogen-Resistant Breast Cancer Cell Lines MCF-7/LCC2 and MCF-7/LCC9
Molecules 2013, 18(1), 701-720; doi:10.3390/molecules18010701
Received: 2 November 2012 / Revised: 24 December 2012 / Accepted: 26 December 2012 / Published: 8 January 2013
Cited by 27 | PDF Full-text (1553 KB) | Supplementary Files
Abstract
Curcumin, a principal component of turmeric (Curcuma longa), has potential therapeutic activities against breast cancer through multiple signaling pathways. Increasing evidence indicates that curcumin reverses chemo-resistance and sensitizes cancer cells to chemotherapy and targeted therapy in breast cancer. To date, few studies [...] Read more.
Curcumin, a principal component of turmeric (Curcuma longa), has potential therapeutic activities against breast cancer through multiple signaling pathways. Increasing evidence indicates that curcumin reverses chemo-resistance and sensitizes cancer cells to chemotherapy and targeted therapy in breast cancer. To date, few studies have explored its potential antiproliferation effects and resistance reversal in antiestrogen-resistant breast cancer. In this study, we therefore investigated the efficacy of curcumin alone and in combination with tamoxifen in the established antiestrogen-resistant breast cancer cell lines MCF-7/LCC2 and MCF-7/LCC9. We discovered that curcumin treatment displayed anti-proliferative and pro-apoptotic activities and induced cell cycle arrest at G2/M phase. Of note, the combination of curcumin and tamoxifen resulted in a synergistic survival inhibition in MCF-7/LCC2 and MCF-7/LCC9 cells. Moreover, we found that curcumin targeted multiple signals involved in growth maintenance and resistance acquisition in endocrine resistant cells. In our cell models, curcumin could suppress expression of pro-growth and anti-apoptosis molecules, induce inactivation of NF-κB, Src and Akt/mTOR pathways and downregulate the key epigenetic modifier EZH2. The above findings suggested that curcumin alone and combinations of curcumin with endocrine therapy may be of therapeutic benefit for endocrine-resistant breast cancer. Full article
Open AccessArticle Synthesis and in Vitro Antiproliferative Activity of New Phenylaminoisoquinolinequinones against Cancer Cell Lines
Molecules 2013, 18(1), 721-734; doi:10.3390/molecules18010721
Received: 10 December 2012 / Revised: 27 December 2012 / Accepted: 31 December 2012 / Published: 8 January 2013
Cited by 3 | PDF Full-text (322 KB)
Abstract
A variety of phenylaminoisoquinolinequinones were synthesized and tested for their antiproliferative activity against three human-tumor derived cancer cell lines. The new aminoquinones were prepared from 4-methoxycarbonyl-3-methylisoquinoline-5,8-quinone (1) via acid-induced amination and bromination reactions. Remarkable differences in antiproliferative activity were observed [...] Read more.
A variety of phenylaminoisoquinolinequinones were synthesized and tested for their antiproliferative activity against three human-tumor derived cancer cell lines. The new aminoquinones were prepared from 4-methoxycarbonyl-3-methylisoquinoline-5,8-quinone (1) via acid-induced amination and bromination reactions. Remarkable differences in antiproliferative activity were observed depending upon the location and donor capacity of the substituted phenylamino group at the quinone nucleus. The effect of the substituents on the biological activity is discussed in terms of the donor-acceptor interactions which were evaluated through the redox properties of the aminoquinones. Full article
Open AccessArticle Benchmarking Ligand-Based Virtual High-Throughput Screening with the PubChem Database
Molecules 2013, 18(1), 735-756; doi:10.3390/molecules18010735
Received: 26 September 2012 / Revised: 11 October 2012 / Accepted: 17 December 2012 / Published: 8 January 2013
Cited by 20 | PDF Full-text (268 KB) | Supplementary Files
Abstract
With the rapidly increasing availability of High-Throughput Screening (HTS) data in the public domain, such as the PubChem database, methods for ligand-based computer-aided drug discovery (LB-CADD) have the potential to accelerate and reduce the cost of probe development and drug discovery efforts [...] Read more.
With the rapidly increasing availability of High-Throughput Screening (HTS) data in the public domain, such as the PubChem database, methods for ligand-based computer-aided drug discovery (LB-CADD) have the potential to accelerate and reduce the cost of probe development and drug discovery efforts in academia. We assemble nine data sets from realistic HTS campaigns representing major families of drug target proteins for benchmarking LB-CADD methods. Each data set is public domain through PubChem and carefully collated through confirmation screens validating active compounds. These data sets provide the foundation for benchmarking a new cheminformatics framework BCL::ChemInfo, which is freely available for non-commercial use. Quantitative structure activity relationship (QSAR) models are built using Artificial Neural Networks (ANNs), Support Vector Machines (SVMs), Decision Trees (DTs), and Kohonen networks (KNs). Problem-specific descriptor optimization protocols are assessed including Sequential Feature Forward Selection (SFFS) and various information content measures. Measures of predictive power and confidence are evaluated through cross-validation, and a consensus prediction scheme is tested that combines orthogonal machine learning algorithms into a single predictor. Enrichments ranging from 15 to 101 for a TPR cutoff of 25% are observed. Full article
(This article belongs to the Special Issue QSAR and Its Applications)
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Open AccessArticle In Vitro and in Vivo Anticancer Activity of Aconitine on Melanoma Cell Line B16
Molecules 2013, 18(1), 757-767; doi:10.3390/molecules18010757
Received: 11 November 2012 / Revised: 29 November 2012 / Accepted: 5 January 2013 / Published: 8 January 2013
Cited by 3 | PDF Full-text (1035 KB)
Abstract
The anti-tumor effect of aconitine in melanoma cell line B16 has been studied in this paper. We found that B16 cells showed significantly reduced growth rates and increased apoptotic effects in the presence of aconitine. Furthermore, aconitine inhibited the PI3K/AKT and MAPK/ERK1/2 [...] Read more.
The anti-tumor effect of aconitine in melanoma cell line B16 has been studied in this paper. We found that B16 cells showed significantly reduced growth rates and increased apoptotic effects in the presence of aconitine. Furthermore, aconitine inhibited the PI3K/AKT and MAPK/ERK1/2 signaling pathways, thus regulating the levels of protein and mRNA of PCNA and apoptotic related signaling molecules. Above all, we found that aconitine showed an anti-melanoma effect in suppressing tumor growth in vivo. In conclusion, we show that aconitine may be a useful anticancer drug in the future. Full article
Open AccessArticle Effects of Selected Polysorbate and Sucrose Ester Emulsifiers on the Physicochemical Properties of Astaxanthin Nanodispersions
Molecules 2013, 18(1), 768-777; doi:10.3390/molecules18010768
Received: 7 December 2012 / Accepted: 31 December 2012 / Published: 9 January 2013
Cited by 9 | PDF Full-text (193 KB)
Abstract
The effects of selected nonionic emulsifiers on the physicochemical characteristics of astaxanthin nanodispersions produced by an emulsification/evaporation technique were studied. The emulsifiers used were polysorbates (Polysorbate 20, Polysorbate 40, Polysorbate 60 and Polysorbate 80) and sucrose esters of fatty acids (sucrose laurate, [...] Read more.
The effects of selected nonionic emulsifiers on the physicochemical characteristics of astaxanthin nanodispersions produced by an emulsification/evaporation technique were studied. The emulsifiers used were polysorbates (Polysorbate 20, Polysorbate 40, Polysorbate 60 and Polysorbate 80) and sucrose esters of fatty acids (sucrose laurate, palmitate, stearate and oleate). The mean particle diameters of the nanodispersions ranged from 70 nm to 150 nm, depending on the emulsifier used. In the prepared nanodispersions, the astaxanthin particle diameter decreased with increasing emulsifier hydrophilicity and decreasing carbon number of the fatty acid in the emulsifier structure. Astaxanthin nanodispersions with the smallest particle diameters were produced with Polysorbate 20 and sucrose laurate among the polysorbates and the sucrose esters, respectively. We also found that the Polysorbate 80- and sucrose oleate-stabilized nanodispersions had the highest astaxanthin losses (i.e., the lowest astaxanthin contents in the final products) among the nanodispersions. This work demonstrated the importance of emulsifier type in determining the physicochemical characteristics of astaxanthin nano-dispersions. Full article
Open AccessArticle Tricolorin A as a Natural Herbicide
Molecules 2013, 18(1), 778-788; doi:10.3390/molecules18010778
Received: 15 November 2012 / Revised: 3 January 2013 / Accepted: 5 January 2013 / Published: 9 January 2013
PDF Full-text (264 KB)
Abstract
Tricolorin A acts as pre- and post-emergence plant growth inhibitor. In pre-emergence it displays broad-spectrum weed control, inhibiting germination of both monocotyledonous (Lolium mutliflorum and Triticum vulgare) and dicotyledonous (Physalis ixocarpa and Trifolium alexandrinum) seeds, being the dicotyledonous [...] Read more.
Tricolorin A acts as pre- and post-emergence plant growth inhibitor. In pre-emergence it displays broad-spectrum weed control, inhibiting germination of both monocotyledonous (Lolium mutliflorum and Triticum vulgare) and dicotyledonous (Physalis ixocarpa and Trifolium alexandrinum) seeds, being the dicotyledonous seeds the most inhibited. Tricolorin A also inhibited seedling growth, and seed respiration, and since the concentrations required for inhibiting both germination and respiration were similar, we suggest that respiration is one of its targets. Tricolorin A at 60 µM acts as a post- emergence plant growth inhibitor by reducing dry plant biomass by 62%, 37%, 33%, and 22% for L. multiflorum, T. alexandrinum, T. vulgare, and P. ixocarpa, respectively, 18 days after its application. In order to determine the potency of tricolorin A as a plant growth inhibitor, paraquat was used as control; the results indicate that tricolorin A acts as a non-selective post-emergence plant growth inhibitor similar to paraquat, since both reduced the biomass production in P. ixocarpa and T. alexandrinum. Therefore, we suggest that tricolorin A will be a good biodegradable herbicide for weeds. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Investigation on the Interaction between Cyclophosphamide and Lysozyme in the Presence of Three Different Kind of Cyclodextrins: Determination of the Binding Mechanism by Spectroscopic and Molecular Modeling Techniques
Molecules 2013, 18(1), 789-813; doi:10.3390/molecules18010789
Received: 12 November 2012 / Revised: 24 December 2012 / Accepted: 4 January 2013 / Published: 11 January 2013
Cited by 29 | PDF Full-text (1923 KB)
Abstract
The interactions between cyclophosphamide (CYC) and lysozyme (LYZ) in the presence of different cyclodextrins (CDs) were investigated by UV absorption, fluorescence spectroscopy, circular dichroism (CD), and molecular modeling techniques under imitated physiological conditions. The UV absorption results showed the formation of complexes [...] Read more.
The interactions between cyclophosphamide (CYC) and lysozyme (LYZ) in the presence of different cyclodextrins (CDs) were investigated by UV absorption, fluorescence spectroscopy, circular dichroism (CD), and molecular modeling techniques under imitated physiological conditions. The UV absorption results showed the formation of complexes between CYC and LYZ in the presence of different CDs. Fluorescence data show that CYC has a stronger quenching effect on LYZ, and the red shifts suggested that the microenvironment of Trp residues was changed and became more hydrophilic. The interaction of CYC with LYZ and quenching properties of the complexes caused strong static fluorescence quenching in binary and ternary systems. The binding affinities as well as the number of binding sites were obtained from interaction between CYC and LYZ in the presence of different CDs as binary and ternary systems by modified Stern-Volmer plots. The Resonance Light Scattering (RLS) technique was utilized to investigate the effect of drug and CDs on conformational changes of LYZ as separate and simultaneous. The results suggested that the enhancement of RLS intensity was attributed to the formation of a complex between drug and protein in absence and presence of CDs. The effect of CYC and cyclodextrins on the conformation of LYZ was analyzed using synchronous fluorescence spectroscopy. Our results revealed that the fluorescence quenching of LYZ originated from the Trp and Tyr residues, and demonstrated conformational changes of LYZ with the addition of CYC and CDs. The molecular distances between the donor (LYZ) and acceptor (CYC and CDs) in binary and ternary systems were estimated according to Forster’s theory and showed static quenching for protein with CYC in the presence of CDs. The CD spectra indicated that the binding of the CYC induced secondary structural changes in LYZ in binary and ternary systems. Molecular modeling suggested the binding sites of CYC in the ternary systems differ from those in the binary systems. estimated the distance between CYC and Trp residues in binary and ternary systems in the presence of CDs and confirmed the experimental results. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle ‘One-pot’ Synthesis of Dihydrobenzo[4,5][1,3]oxazino[2,3-a] isoquinolines via a Silver(I)-Catalyzed Cascade Approach
Molecules 2013, 18(1), 814-831; doi:10.3390/molecules18010814
Received: 26 November 2012 / Revised: 4 January 2013 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 4 | PDF Full-text (318 KB) | Supplementary Files
Abstract
An efficient approach for the synthesis of biologically interesting fused tetracyclic isoquinolines in high yields and with a broad substrate scope has been developed. The strategy features an AgNO3 catalyzed ‘one-pot’ cascade process involving formation of two new C–N bonds and [...] Read more.
An efficient approach for the synthesis of biologically interesting fused tetracyclic isoquinolines in high yields and with a broad substrate scope has been developed. The strategy features an AgNO3 catalyzed ‘one-pot’ cascade process involving formation of two new C–N bonds and one new C–O bond. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Synthesis and Antibacterial Evaluation of Novel Heterocyclic Compounds Containing a Sulfonamido Moiety
Molecules 2013, 18(1), 832-844; doi:10.3390/molecules18010832
Received: 31 October 2012 / Revised: 4 January 2013 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 15 | PDF Full-text (294 KB)
Abstract
Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity [...] Read more.
Aiming for the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have high activities. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Chamaejasmine Arrests Cell Cycle, Induces Apoptosis and Inhibits Nuclear NF-κB Translocation in the Human Breast Cancer Cell Line MDA-MB-231
Molecules 2013, 18(1), 845-858; doi:10.3390/molecules18010845
Received: 19 November 2012 / Revised: 4 January 2013 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 10 | PDF Full-text (1119 KB)
Abstract
In this study, the anticancer activity of chamaejasmine was characterized in the human breast cancer cell line, MDA-MB-231. Cell viability and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Western blotting was performed to determine changes in levels [...] Read more.
In this study, the anticancer activity of chamaejasmine was characterized in the human breast cancer cell line, MDA-MB-231. Cell viability and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Western blotting was performed to determine changes in levels of various proteins. Results showed that treatment with chamaejasmine (4–16 μM) inhibited cell proliferation, which correlated with G2/M phase arrest and apoptosis in MDA-MB-231 cells. Chamaejasmine treatment of MDA-MB-231 cells resulted in induction of WAF1/p21 and KIP1/p27, decrease in cyclins A and cyclins B1. Cyclin-dependent kinase (cdk) 2 and cdc2 was also decreased after chamaejasmine treatment. Moreover, inhibition of nuclear translocation, phosphorylation of NF-κB, activation of IKKα and IKKβ, inhibition of phosphorylation and degradation of IκBα were also detected in this work. Our findings suggested that chamaejasmine could be explored as a preventive and perhaps as a chemotherapeutic agent in the management of breast cancer. Full article
Open AccessArticle Structural Characterization of de Novo Designed L5K5W Model Peptide Isomers with Potent Antimicrobial and Varied Hemolytic Activities
Molecules 2013, 18(1), 859-876; doi:10.3390/molecules18010859
Received: 4 December 2012 / Revised: 4 January 2013 / Accepted: 7 January 2013 / Published: 11 January 2013
Cited by 5 | PDF Full-text (599 KB)
Abstract
In an effort to develop short antimicrobial peptides with simple amino acid compositions, we generated a series of undecapeptide isomers having the L5K5W formula. Amino acid sequences were designed to be perfectly amphipathic when folded into a helical [...] Read more.
In an effort to develop short antimicrobial peptides with simple amino acid compositions, we generated a series of undecapeptide isomers having the L5K5W formula. Amino acid sequences were designed to be perfectly amphipathic when folded into a helical conformation by converging leucines onto one side and lysines onto the other side of the helical axis. The single tryptophans, whose positions were varied in the primary structures, were located commonly at the critical amphipathic interface in the helical wheel projection. Helical conformations and the tryptophanyl environments of the 11 L5K5W peptides were confirmed and characterized by circular dichroism, fluorescence and nuclear magnetic resonance spectroscopy. All of the isomers exhibited a potent, broad-spectrum of antibacterial activity with just a slight variance in individual potency, whereas their hemolytic activities against human erythrocytes were significantly diversified. Interestingly, helical dispositions and fluorescence blue shifts of the peptides in aqueous trifluoroethanol solutions, rather than in detergent micelles, showed a marked linear correlation with their hemolytic potency. These results demonstrate that our de novo design strategy for amphipathic helical model peptides is effective for developing novel antimicrobial peptides and their hemolytic activities can be estimated in correlation with structural parameters. Full article
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Open AccessArticle Synthesis, Crystal Structure, Vibration Spectral, and DFT Studies of 4-Aminoantipyrine and Its Derivatives
Molecules 2013, 18(1), 877-893; doi:10.3390/molecules18010877
Received: 26 November 2012 / Revised: 2 January 2013 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 21 | PDF Full-text (857 KB)
Abstract
Three compounds derived from 4-aminoantipyrine (AA) were synthesized and their structures confirmed by melting point, elemental analysis, FT-IR, and 1H-NMR. The molecular structures of the four compounds were characterized by single-crystal X-ray diffraction and calculated by using the density functional theory [...] Read more.
Three compounds derived from 4-aminoantipyrine (AA) were synthesized and their structures confirmed by melting point, elemental analysis, FT-IR, and 1H-NMR. The molecular structures of the four compounds were characterized by single-crystal X-ray diffraction and calculated by using the density functional theory (DFT) method with 6-31G (d) basis set. The calculated molecular geometries and the vibration frequencies of the AA derivatives in the ground state have been compared with the experimental data. The results show that the optimized geometries can reproduce well the crystal structural parameters, and the theoretical vibration frequencies show good agreement with the experimental data, although the experimental data are different from the theoretical ones due to the intermolecular forces. Besides, the molecular electrostatic potential (MEP) and the frontier molecular orbital (FMO) analysis of the compounds were investigated by theoretical calculations. Full article
(This article belongs to the Section Molecular Diversity)
Open AccessArticle Dibenzo[1,2,5]thiadiazepines Are Non-Competitive GABAA Receptor Antagonists
Molecules 2013, 18(1), 894-913; doi:10.3390/molecules18010894
Received: 14 December 2012 / Revised: 31 December 2012 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 1 | PDF Full-text (371 KB)
Abstract
A new process for obtaining dibenzo[c,f][1,2,5]thiadiazepines (DBTDs) and their effects on GABAA receptors of guinea pig myenteric neurons are described. Synthesis of DBTD derivatives began with two commercial aromatic compounds. An azide group was obtained after two sequential reactions, and the [...] Read more.
A new process for obtaining dibenzo[c,f][1,2,5]thiadiazepines (DBTDs) and their effects on GABAA receptors of guinea pig myenteric neurons are described. Synthesis of DBTD derivatives began with two commercial aromatic compounds. An azide group was obtained after two sequential reactions, and the central ring was closed via a nitrene to obtain the tricyclic sulfonamides (DBTDs). Whole-cell recordings showed that DBTDs application did not affect the holding current but inhibited the currents induced by GABA (IGABA), which are mediated by GABAA receptors. These DBTDs effects reached their maximum 3 min after application and were: (i) reversible, (ii) concentration-dependent (with a rank order of potency of 2c = 2d > 2b), (iii) mediated by a non-competitive antagonism, and (iv) only observed when applied extracellularly. Picrotoxin (which binds in the channel mouth) and DBTDs effects were not modified when both substances were simultaneous applied. Our results indicate that DBTD acted on the extracellular domain of GABAA channels but independent of the picrotoxin, benzodiazepine, and GABA binding sites. DBTDs used here could be the initial model for synthesizing new GABAA receptor inhibitors with a potential to be used as antidotes for positive modulators of these receptors or to induce experimental epilepsy. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Synthesis of 5α-Androstane-17-spiro-δ-lactones with a 3-Keto, 3-Hydroxy, 3-Spirocarbamate or 3-Spiromorpholinone as Inhibitors of 17β-Hydroxysteroid Dehydrogenases
Molecules 2013, 18(1), 914-933; doi:10.3390/molecules18010914
Received: 3 December 2012 / Revised: 24 December 2012 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 4 | PDF Full-text (315 KB)
Abstract
We synthesized two series of androstane derivatives as inhibitors of type 3 and type 5 17β-hydroxysteroid dehydrogenases (17β-HSDs). In the first series, four monospiro derivatives at position C17 were prepared from androsterone (ADT) or epi-ADT. After the protection of the alcohol [...] Read more.
We synthesized two series of androstane derivatives as inhibitors of type 3 and type 5 17β-hydroxysteroid dehydrogenases (17β-HSDs). In the first series, four monospiro derivatives at position C17 were prepared from androsterone (ADT) or epi-ADT. After the protection of the alcohol at C3, the C17-ketone was alkylated with the lithium acetylide of tetrahydro-2-(but-3-ynyl)-2-H-pyran, the triple bond was hydrogenated, the protecting groups hydrolysed and the alcohols oxidized to give the corresponding 3-keto-17-spiro-lactone derivative. The other three compounds were generated from this keto-lactone by reducing the ketone at C3, or by introducing one or two methyl groups. In the second series, two dispiro derivatives at C3 and C17 were prepared from epi-ADT. After introducing a spiro-δ-lactone at C17 and an oxirane at C3, an aminolysis of the oxirane with L-isoleucine methyl ester provided an amino alcohol, which was treated with triphosgene or sodium methylate to afford a carbamate- or a morpholinone-androstane derivative, respectively. These steroid derivatives inhibited 17β-HSD3 (14–88% at 1 μM; 46–94% at 10 μM) and 17β-HSD5 (54–73% at 0.3 μM; 91–92% at 3 μM). They did not produce any androgenic activity and did not bind steroid (androgen, estrogen, glucocorticoid and progestin) receptors, suggesting a good profile for prostate cancer therapy. Full article
(This article belongs to the Special Issue Spiro Compounds)
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Open AccessArticle Total Flavonoids of Scutellaria barbata Inhibit Invasion of Hepatocarcinoma via MMP/TIMP in Vitro
Molecules 2013, 18(1), 934-950; doi:10.3390/molecules18010934
Received: 28 November 2012 / Revised: 22 December 2012 / Accepted: 5 January 2013 / Published: 11 January 2013
Cited by 9 | PDF Full-text (831 KB)
Abstract
Metastasis is the major cause of cancer-related deaths. Targeting the process of metastasis has been proposed as a strategy to fight cancer. Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is used for treatment of many diseases, including [...] Read more.
Metastasis is the major cause of cancer-related deaths. Targeting the process of metastasis has been proposed as a strategy to fight cancer. Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is used for treatment of many diseases, including cancer. This study aimed to determine the anti-metastatic effect of total flavonoids of S. barbata (TF-SB) using the human hepatocarcinoma MHCC97H cell line with high metastatic potential. Our results show that TF-SB could significantly inhibit the proliferation and invasion of MHCC97H cells in a dose-dependent manner. MMP-2 and MMP-9 expression were obviously decreased after TF-SB treatment at both the mRNA and protein level. TIMP-1 and TIMP-2 expression were simultaneously increased. The present study indicates that TF-SB could reduce the metastatic capability of MHCC97H cell, probably through decrease of the MMP expression, and simultaneous increase of the TIMP expression. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Investigating the Antioxidant and Acetylcholinesterase Inhibition Activities of Gossypium herbaceam
Molecules 2013, 18(1), 951-962; doi:10.3390/molecules18010951
Received: 6 November 2012 / Revised: 30 December 2012 / Accepted: 4 January 2013 / Published: 14 January 2013
Cited by 11 | PDF Full-text (257 KB)
Abstract
Our previous research showed that standardized extract from the flowers of the Gossypium herbaceam labeled GHE had been used in clinical trials for its beneficial effects on brain functions, particularly in connection with age-related dementia and Alzheimer’s disease (AD). The aim of [...] Read more.
Our previous research showed that standardized extract from the flowers of the Gossypium herbaceam labeled GHE had been used in clinical trials for its beneficial effects on brain functions, particularly in connection with age-related dementia and Alzheimer’s disease (AD). The aim of this work was to determine the components of this herb and the individual constituents of GHE. In order to better understand this herb for AD treatment, we investigated the acetylcholinesterase (AChE) inhibition and antioxidant activity of GHE as well as the protective effects to PC12 cells against cytotoxicity induced by tertiary butyl hydroperoxide (tBHP) using in vitro assays. The antioxidant activities were assessed by measuring their capabilities for scavenging 1,1-diphenyl-2-picylhydrazyl (DPPH) and 2-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical as well as in inhibiting lipid peroxidation. Our data showed that GHE exhibited certain activities against AChE and also is an efficient free radical scavenger, which may be helpful in preventing or alleviating patients suffering from AD. Full article
Open AccessArticle Chemical Composition and Antibacterial Activity of Essential Oils from Different Parts of Leonurus japonicus Houtt.
Molecules 2013, 18(1), 963-973; doi:10.3390/molecules18010963
Received: 10 December 2012 / Revised: 30 December 2012 / Accepted: 4 January 2013 / Published: 14 January 2013
Cited by 17 | PDF Full-text (225 KB)
Abstract
The herb and fruits of Leonurus japonicus Houtt., named “Yimucao” and “Chongweizi”, respectively, in Chinese, have been widely used in China as gynecological medicines. The components of the essential oils obtained by hydrodistillation were investigated by GC-MS. The antibacterial activity of the [...] Read more.
The herb and fruits of Leonurus japonicus Houtt., named “Yimucao” and “Chongweizi”, respectively, in Chinese, have been widely used in China as gynecological medicines. The components of the essential oils obtained by hydrodistillation were investigated by GC-MS. The antibacterial activity of the essential oils was determined by micro-dilution assay. The results showed large variations in the chemical composition and antibacterial activity of the oils. The oil of “Yimucao” showed antibacterial activity against various Gram-positive bacteria and consisted mainly of sesquiterpenes and diterpenes, with phytone, phytol, caryophyllene oxide and β-caryophyllene being the most significant constituents, whereas the oil of “Chongweizi”, mainly made up of bornyl acetate and aliphatic hydrocarbons, was inactive in the antibacterial assay. Further study of the main compounds in “Yimucao oil” showed that β-caryophyllene had wide-spectrum activity against Gram-positive bacteria. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Comparative ANNs with Different Input Layers and GA-PLS Study for Simultaneous Spectrofluorimetric Determination of Melatonin and Pyridoxine HCl in the Presence of Melatonin’s Main Impurity
Molecules 2013, 18(1), 974-996; doi:10.3390/molecules18010974
Received: 19 October 2012 / Revised: 26 December 2012 / Accepted: 31 December 2012 / Published: 14 January 2013
Cited by 4 | PDF Full-text (455 KB)
Abstract
Melatonin (MLT) has many health implications, therefore it is important to develop specific analytical methods for the determination of MLT in the presence of its main impurity, N-{2-[1-({3-[2-(acetylamino)ethyl]-5-methoxy-1H-indol-2-yl}methyl)-5-methoxy-1H-indol-3-yl]ethyl}acetaamide (DMLT) and pyridoxine HCl (PNH) as a co-formulated drug. [...] Read more.
Melatonin (MLT) has many health implications, therefore it is important to develop specific analytical methods for the determination of MLT in the presence of its main impurity, N-{2-[1-({3-[2-(acetylamino)ethyl]-5-methoxy-1H-indol-2-yl}methyl)-5-methoxy-1H-indol-3-yl]ethyl}acetaamide (DMLT) and pyridoxine HCl (PNH) as a co-formulated drug. This work describes simple, sensitive, and reliable four multivariate calibration methods, namely artificial neural network preceded by genetic algorithm (GA-ANN), principal component analysis (PCA-ANN) and wavelet transform procedures (WT-ANN) as well as partial least squares preceded by genetic algorithm (GA-PLS) for the spectrofluorimetric determination of MLT and PNH in the presence of DMLT. Analytical performance of the proposed methods was statistically validated with respect to linearity, accuracy, precision and specificity. The proposed methods were successfully applied for the assay of MLT in laboratory prepared mixtures containing up to 15% of DMLT and in commercial MLT tablets with recoveries of no less than 99.00%. No interference was observed from common pharmaceutical additives and the results compared favorably with those obtained by a reference method. Full article
Open AccessArticle Supercritical Carbon Dioxide Extraction of Seed Oil from Winter Melon (Benincasa hispida) and Its Antioxidant Activity and Fatty Acid Composition
Molecules 2013, 18(1), 997-1014; doi:10.3390/molecules18010997
Received: 8 October 2012 / Revised: 17 December 2012 / Accepted: 19 December 2012 / Published: 15 January 2013
Cited by 9 | PDF Full-text (705 KB)
Abstract
In the present study, supercritical carbon dioxide (SC-CO2) extraction of seed oil from winter melon (Benincasa hispida) was investigated. The effects of process variables namely pressure (150–300 bar), temperature (40–50 °C) and dynamic extraction time (60–120 min) on [...] Read more.
In the present study, supercritical carbon dioxide (SC-CO2) extraction of seed oil from winter melon (Benincasa hispida) was investigated. The effects of process variables namely pressure (150–300 bar), temperature (40–50 °C) and dynamic extraction time (60–120 min) on crude extraction yield (CEY) were studied through response surface methodology (RSM). The SC-CO2 extraction process was modified using ethanol (99.9%) as co-solvent. Perturbation plot revealed the significant effect of all process variables on the CEY. A central composite design (CCD) was used to optimize the process conditions to achieve maximum CEY. The optimum conditions were 244 bar pressure, 46 °C temperature and 97 min dynamic extraction time. Under these optimal conditions, the CEY was predicted to be 176.30 mg-extract/g-dried sample. The validation experiment results agreed with the predicted value. The antioxidant activity and fatty acid composition of crude oil obtained under optimized conditions were determined and compared with published results using Soxhlet extraction (SE) and ultrasound assisted extraction (UAE). It was found that the antioxidant activity of the extract obtained by SC-CO2 extraction was strongly higher than those obtained by SE and UAE. Identification of fatty acid composition using gas chromatography (GC) showed that all the extracts were rich in unsaturated fatty acids with the most being linoleic acid. In contrast, the amount of saturated fatty acids extracted by SE was higher than that extracted under optimized SC-CO2 extraction conditions. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Chitosan Rate of Uptake in HEK293 Cells is Influenced by Soluble versus Microparticle State and Enhanced by Serum-Induced Cell Metabolism and Lactate-Based Media Acidification
Molecules 2013, 18(1), 1015-1035; doi:10.3390/molecules18011015
Received: 16 November 2012 / Revised: 30 December 2012 / Accepted: 7 January 2013 / Published: 15 January 2013
Cited by 5 | PDF Full-text (2589 KB)
Abstract
Chitosan is a biocompatible polysaccharide composed of glucosamine and N-acetylglucosamine. The polymer has a unique behavior of fluctuating between soluble chains at pH 6 and insoluble microparticles at pH 7. The purpose of this study was to test the hypothesis that [...] Read more.
Chitosan is a biocompatible polysaccharide composed of glucosamine and N-acetylglucosamine. The polymer has a unique behavior of fluctuating between soluble chains at pH 6 and insoluble microparticles at pH 7. The purpose of this study was to test the hypothesis that chitosan structure, solubility state, and serum influence the rate of cell uptake. Chitosans with 80% and 95% degree of deacetylation (medium and low viscosity) were tagged with rhodamine and analyzed for particle size, media solubility, and uptake by HEK293 epithelial cells using live confocal microscopy and flow cytometry. In media pH 7.4 with or without 10% serum, chitosans fully precipitated into 0.5 to 1.4 µm diameter microparticles with a slight negative charge. During 24 h of culture in serum-free medium, chitosan particles remained extracellular. In cultures with serum, particles were taken up into intracellular vesicles in a serum dose-dependent manner. Opsonization of chitosan with serum, or replacement of serum by epidermal growth factor (EGF) failed to mediate serum-free chitosan particle uptake. Serum stimulated cells to acidify the media, partly by lactate generation. Media acidified to pH 6.5 by 7 mM lactate maintained 50% of chitosan in the soluble fraction, and led to minor uniform serum-free uptake in small vesicles. Conclusion: Media acidification mediates minor in vitro uptake of non-biofouled soluble chitosan chains, while serum-biofouled insoluble chitosan microparticles require sustained serum exposure to generate energy required for macropinocytosis. Full article
(This article belongs to the Special Issue Chitins and Chitosans)
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Open AccessArticle Comparative Analysis of Thermal Behavior, Isothermal Crystallization Kinetics and Polymorphism of Palm Oil Fractions
Molecules 2013, 18(1), 1036-1052; doi:10.3390/molecules18011036
Received: 5 November 2012 / Revised: 31 December 2012 / Accepted: 7 January 2013 / Published: 15 January 2013
Cited by 8 | PDF Full-text (511 KB)
Abstract
Thermal behavior of palm stearin (PS) and palm olein (PO) was explored by monitoring peak temperature transitions by differential scanning calorimetry (DSC). The fatty acid composition (FAC), isothermal crystallization kinetics studied by pulsed Nuclear Magnetic Resonance (pNMR) and isothermal microstructure were also [...] Read more.
Thermal behavior of palm stearin (PS) and palm olein (PO) was explored by monitoring peak temperature transitions by differential scanning calorimetry (DSC). The fatty acid composition (FAC), isothermal crystallization kinetics studied by pulsed Nuclear Magnetic Resonance (pNMR) and isothermal microstructure were also compared. The results indicated that the fatty acid composition had an important influence on the crystallization process. PS and PO both exhibited more multiple endotherms than exotherms which showed irregular peak shapes. An increasing in cooling rate, generally, was associated with an increase in peak size. Application of the Avaimi equation to isothermal crystallization of PS and PO revealed different nucleation and growth mechanisms based on the Avrami exponents. PS quickly reached the end of crystallization because of more saturated triacylglycerol (TAG). The Avrami index of PS were the same as PO under the same isothermal condition at lower temperatrue, indicating that the crystallization mechanism of the two samples based on super-cooling state were the same. According to the polarized light microscope (PLM) images, crystal morphology of PS and PO was different. With the temperature increased, the structure of crystal network of both PS and PO gradually loosened. Full article
Open AccessArticle Antiprotozoal Activity of Quinonemethide Triterpenes from Maytenus ilicifolia (Celastraceae)
Molecules 2013, 18(1), 1053-1062; doi:10.3390/molecules18011053
Received: 19 November 2012 / Revised: 18 December 2012 / Accepted: 21 December 2012 / Published: 15 January 2013
Cited by 10 | PDF Full-text (229 KB)
Abstract
The present study describes the leishmanicidal and trypanocidal activities of two quinonemethide triterpenes, maytenin (1) and pristimerin (2), isolated from Maytenus ilicifolia root barks (Celastraceae). The compounds were effective against the Trypanosomatidae Leishmania amazonensis and Leishmania chagasi and [...] Read more.
The present study describes the leishmanicidal and trypanocidal activities of two quinonemethide triterpenes, maytenin (1) and pristimerin (2), isolated from Maytenus ilicifolia root barks (Celastraceae). The compounds were effective against the Trypanosomatidae Leishmania amazonensis and Leishmania chagasi and Trypanosoma cruzi, etiologic agents of leishmaniasis and Chagas’ disease, respectively. The quinonemethide triterpenes 1 and 2 exhibited a marked in vitro leishmanicidal activity against promastigotes and amastigotes with 50% inhibitory concentration (IC50) values of less than 0.88 nM. Both compounds showed IC50 lower than 0.3 nM against Trypanosoma cruzi epimastigotes. The selectivity indexes (SI) based on BALB/c macrophages for L. amazonensis and L. chagasi were 243.65 and 46.61 for (1) and 193.63 and 23.85 for (2) indicating that both compounds presented high selectivity for Leishmania sp. The data here presented suggests that these compounds should be considered in the development of new and more potent drugs for the treatment of leishmaniasis and Chagas’ disease. Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
Open AccessArticle Optimization of Ultrasonic Assisted Extraction of Antioxidants from Black Soybean (Glycine max var) Sprouts Using Response Surface Methodology
Molecules 2013, 18(1), 1101-1110; doi:10.3390/molecules18011101
Received: 22 November 2012 / Revised: 24 December 2012 / Accepted: 28 December 2012 / Published: 16 January 2013
Cited by 16 | PDF Full-text (312 KB)
Abstract
Response surface methodology (RSM) using a central composite design (CCD) was employed to optimize the conditions for extraction of antioxidants from black soybean (Glycine max var) sprouts. Three influencing factors: liquid-solid ratio, period of ultrasonic assisted extraction and extraction temperature were [...] Read more.
Response surface methodology (RSM) using a central composite design (CCD) was employed to optimize the conditions for extraction of antioxidants from black soybean (Glycine max var) sprouts. Three influencing factors: liquid-solid ratio, period of ultrasonic assisted extraction and extraction temperature were investigated in the ultrasonic aqueous extraction. Then Response Surface Methodology (RSM) was applied to optimize the extraction process focused on DPPH radical-scavenging capacity of the antioxidants with respect to the above influencing factors. The best combination of each significant factor was determined by RSM design and optimum pretreatment conditions for maximum radical-scavenging capacity were established to be liquid-solid ratio of 29.19:1, extraction time of 32.13 min, and extraction temperature of 30 °C. Under these conditions, 67.60% of DPPH radical-scavenging capacity was observed experimentally, similar to the theoretical prediction of 66.36%. Full article
Open AccessArticle Solid Phase versus Solution Phase Synthesis of Heterocyclic Macrocycles
Molecules 2013, 18(1), 1111-1121; doi:10.3390/molecules18011111
Received: 11 November 2012 / Revised: 10 January 2013 / Accepted: 10 January 2013 / Published: 16 January 2013
Cited by 4 | PDF Full-text (371 KB) | Supplementary Files
Abstract
Comparing a solution phase route to a solid phase route in the synthesis of the cytotoxic natural product urukthapelstatin A (Ustat A) confirmed that a solid phase method is superior. The solution phase approach was tedious and involved cyclization of a ridged [...] Read more.
Comparing a solution phase route to a solid phase route in the synthesis of the cytotoxic natural product urukthapelstatin A (Ustat A) confirmed that a solid phase method is superior. The solution phase approach was tedious and involved cyclization of a ridged heterocyclic precursor, while solid phase allowed the rapid generation of a flexible linear peptide. Cyclization of the linear peptide was facile and subsequent generation of three oxazoles located within the structure of Ustat A proved relatively straightforward. Given the ease with which the oxazole Ustat A precursor is formed via our solid phase approach, this route is amenable to rapid analog synthesis. Full article
(This article belongs to the Special Issue Chemical Protein and Peptide Synthesis)
Open AccessCommunication Ligand Binding Affinities of Arctigenin and Its Demethylated Metabolites to Estrogen Receptor Alpha
Molecules 2013, 18(1), 1122-1127; doi:10.3390/molecules18011122
Received: 8 October 2012 / Revised: 10 January 2013 / Accepted: 14 January 2013 / Published: 16 January 2013
Cited by 6 | PDF Full-text (165 KB)
Abstract
Phytoestrogens are defined as plant-derived compounds with estrogen-like activities according to their chemical structures and activities. Plant lignans are generally categorized as phytoestrogens. It was reported that (−)-arctigenin, the aglycone of arctiin, was demethylated to (−)-dihydroxyenterolactone (DHENL) by Eubacterium (E.) sp. ARC-2. [...] Read more.
Phytoestrogens are defined as plant-derived compounds with estrogen-like activities according to their chemical structures and activities. Plant lignans are generally categorized as phytoestrogens. It was reported that (−)-arctigenin, the aglycone of arctiin, was demethylated to (−)-dihydroxyenterolactone (DHENL) by Eubacterium (E.) sp. ARC-2. Through stepwise demethylation, E. sp. ARC-2 produced six intermediates, three mono-desmethylarctigenins and three di-desmethylarctigenins. In the present study, ligand binding affinities of (−)-arctigenin and its seven metabolites, including DHENL, were investigated for an estrogen receptor alpha, and found that demethylated metabolites had stronger binding affinities than (−)-arctigenin using a ligand binding screen assay method. The IC50 value of (2R,3R)-2-(4-hydroxy-3-methoxybenzyl)-3-(3,4-dihydroxybenzyl)-butyrolactone was 7.9 × 10−4 M. Full article
Open AccessArticle Antioxidant and Antimicrobial Activities of 7-Hydroxy-calamenene-Rich Essential Oils from Croton cajucara Benth.
Molecules 2013, 18(1), 1128-1137; doi:10.3390/molecules18011128
Received: 29 November 2012 / Revised: 4 January 2013 / Accepted: 11 January 2013 / Published: 16 January 2013
Cited by 9 | PDF Full-text (199 KB)
Abstract
Croton cajucara is a shrub native to the Amazon region locally known as “sacaca”. Two morphotypes are known: white and red “sacaca”. The essential oils (EO) obtained by hydrodistillation from leaves of the red morphotype were, in general, rich in 7-hydroxycalamenene (28.4%–37.5%). [...] Read more.
Croton cajucara is a shrub native to the Amazon region locally known as “sacaca”. Two morphotypes are known: white and red “sacaca”. The essential oils (EO) obtained by hydrodistillation from leaves of the red morphotype were, in general, rich in 7-hydroxycalamenene (28.4%–37.5%). The effectiveness of these EO regarding the antimicrobial activity against pathogenic microorganisms was initially investigated by the drop test method, showing significant inhibition zones. Among the microorganisms tested, the essential oils rich in 7-hydroxycalamenene were more effective against methicillin resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Mycobacterium tuberculosis, M. smegmatis, Mucor circinelloides and Rhizopus oryzae. The minimum inhibitory concentrations (MIC) of the oils were determined using the broth dilution assay. It was possible to observe that 7-hydroxycalamenene-rich oils presented high antimicrobial activity, with MIC of 4.76 × 10−3 μg/mL for MRSA, 4.88 μg/mL for M. tuberculosis, 39.06 μg/mL for M. smegmatis, and 0.152 μg/mL for R. oryzae and 3.63 × 10−8 μg/mL for M. circinelloides. The antioxidant activity of this EO suggests that 7-hydroxycalamenene provides more antioxidant activity according with EC50 less than 63.59 μg/mL. Considering the bioactive potential of EOs and 7-hydroxycalamenene could be of great interest for development of antimicrobials for therapeutic use in treatment of bacterial and fungal infections in humans and/or veterinary practice. Full article
(This article belongs to the Special Issue Antioxidants 2012)
Open AccessArticle Improvement of the Enzyme Performance of Trypsin via Adsorption in Mesoporous Silica SBA-15: Hydrolysis of BAPNA
Molecules 2013, 18(1), 1138-1149; doi:10.3390/molecules18011138
Received: 3 December 2012 / Revised: 9 January 2013 / Accepted: 10 January 2013 / Published: 16 January 2013
Cited by 6 | PDF Full-text (470 KB)
Abstract
The enzymatic performance of trypsin in hydrolysis of N-α-benzoyl-DL-arginine-4-nitroanilide (BAPNA) was improved by adsorption on Santa Barbara Amorphous (SBA)-15 mesoporous silica. The optimal immobilization conditions were screened and the properties of immobilized enzyme have also been studied. Under the optimal conditions, [...] Read more.
The enzymatic performance of trypsin in hydrolysis of N-α-benzoyl-DL-arginine-4-nitroanilide (BAPNA) was improved by adsorption on Santa Barbara Amorphous (SBA)-15 mesoporous silica. The optimal immobilization conditions were screened and the properties of immobilized enzyme have also been studied. Under the optimal conditions, the immobilized trypsin displays maximum specific activity (49.8 μmol/min/g). The results also indicate that the immobilized trypsin exhibits better storage stability. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Bioassay-Guided Isolation of DPP-4 Inhibitory Fractions from Extracts of Submerged Cultured of Inonotus obliquus
Molecules 2013, 18(1), 1150-1161; doi:10.3390/molecules18011150
Received: 21 November 2012 / Revised: 7 December 2012 / Accepted: 14 January 2013 / Published: 16 January 2013
Cited by 9 | PDF Full-text (280 KB)
Abstract
Inonotus obliquus is a medicinal mushroom used in Russian and Eastern European folk medicine for the treatment of gastrointestinal cancer, cardiovascular disease and diabetes. Previous studies in our laboratory have demonstrated that the mycelium powders of I. obliquus possess significant antihyperglycemic effects [...] Read more.
Inonotus obliquus is a medicinal mushroom used in Russian and Eastern European folk medicine for the treatment of gastrointestinal cancer, cardiovascular disease and diabetes. Previous studies in our laboratory have demonstrated that the mycelium powders of I. obliquus possess significant antihyperglycemic effects in a mouse model of diabetic disease induced by alloxan. However, the active ingredients of mycelium powders responsible for the diabetes activity have not been identified. This study aims to identify the active ingredients of I. obliquus mycelium powders by a bioassay-guided fractionation approach and explore the mechanism of action of these active ingredients by using a well-established DPP-4 (an important enzyme as a new therapeutic target for diabetes) inhibitory assay model. The results showed the chloroform extract of mycelium was potential inhibitory against DPP-4. Bioactivity guided fractionation led to the identification of 19 compounds using UPLC-Q-TOF-MS. Molecular docking between the compounds and DPP-4 revealed that compounds 5, 8, 9, 14, 15 may be the active components responsible for the DPP-4 inhibitory activity. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle A Facile Synthesis of Fully Protected meso-Diaminopimelic Acid (DAP) and Its Application to the Preparation of Lipophilic N-Acyl iE-DAP
Molecules 2013, 18(1), 1162-1173; doi:10.3390/molecules18011162
Received: 5 December 2012 / Revised: 8 January 2013 / Accepted: 9 January 2013 / Published: 16 January 2013
Cited by 7 | PDF Full-text (269 KB)
Abstract
Synthesis of beneficial protected meso-DAP 9 by cross metathesis of the Garner aldehyde-derived vinyl glycine 1b with protected allyl glycine 2 in the presence of Grubbs second-generation catalyst was performed. Preparation of lipophilic N-acyl iE-DAP as potent agonists of NOD [...] Read more.
Synthesis of beneficial protected meso-DAP 9 by cross metathesis of the Garner aldehyde-derived vinyl glycine 1b with protected allyl glycine 2 in the presence of Grubbs second-generation catalyst was performed. Preparation of lipophilic N-acyl iE-DAP as potent agonists of NOD 1-mediated immune response from 9 is described. Full article
(This article belongs to the Special Issue Chemical Protein and Peptide Synthesis)
Open AccessArticle Diastereoselective Synthesis of 5-Hydroxy-8-methoxy-1-oxaspiro[5,5]undeca-7,10-diene-9-one
Molecules 2013, 18(1), 1174-1180; doi:10.3390/molecules18011174
Received: 13 December 2012 / Revised: 10 January 2013 / Accepted: 14 January 2013 / Published: 17 January 2013
PDF Full-text (262 KB)
Abstract
A short five steps synthesis of the title compound from vanillin is described. The racemic spiroether 7 was obtained in 61% yield and in >99% diastereomeric excess (by 1H-NMR) from the corresponding phenolic derivative 3 by oxidation with lead (IV) acetate. [...] Read more.
A short five steps synthesis of the title compound from vanillin is described. The racemic spiroether 7 was obtained in 61% yield and in >99% diastereomeric excess (by 1H-NMR) from the corresponding phenolic derivative 3 by oxidation with lead (IV) acetate. Full article
Open AccessArticle Two Cerebrosides Isolated from the Seeds of Sterculia lychnophora and Their Neuroprotective Effect
Molecules 2013, 18(1), 1181-1187; doi:10.3390/molecules18011181
Received: 22 November 2012 / Revised: 25 December 2012 / Accepted: 8 January 2013 / Published: 17 January 2013
Cited by 2 | PDF Full-text (220 KB)
Abstract
Two cerebrosides named 1-O-b-D-glucopyranosyl-(2S,3R,4E,8Z)-2-[(2-hydroxyoctadecanoyl)amido]-4,8-octadecadiene-1,3-diol (1) and soya-cerebroside I (2) were isolated from the seeds of Sterculia lychnophora for the first time. Their structures were completely characterized [...] Read more.
Two cerebrosides named 1-O-b-D-glucopyranosyl-(2S,3R,4E,8Z)-2-[(2-hydroxyoctadecanoyl)amido]-4,8-octadecadiene-1,3-diol (1) and soya-cerebroside I (2) were isolated from the seeds of Sterculia lychnophora for the first time. Their structures were completely characterized by spectroscopic methods including IR, MS and NMR. Compound 1 exhibited moderate neuroprotective effect against SH-SY5Y cell damage induced by hydrogen peroxide. Full article
(This article belongs to the Section Natural Products)
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Open AccessArticle Protective Effect of Ginsenoside Rb1 Against Lung Injury Induced by Intestinal Ischemia-Reperfusion in Rats
Molecules 2013, 18(1), 1214-1226; doi:10.3390/molecules18011214
Received: 13 December 2012 / Revised: 5 January 2013 / Accepted: 11 January 2013 / Published: 17 January 2013
Cited by 12 | PDF Full-text (988 KB)
Abstract
Intestinal ischemia-reperfusion (I/R) is a critical event in the pathogenesis of multiple organ dysfunction syndromes (MODS). The lungs are some of the most vulnerable organs that are impacted by intestinal I/R. The aim of this study is to investigate whether ginsenoside Rb1 [...] Read more.
Intestinal ischemia-reperfusion (I/R) is a critical event in the pathogenesis of multiple organ dysfunction syndromes (MODS). The lungs are some of the most vulnerable organs that are impacted by intestinal I/R. The aim of this study is to investigate whether ginsenoside Rb1 can ameliorate remote lung injury induced by intestinal I/R. Adult male Wistar rats were randomly divided into four groups: (1) a control, sham-operated group (sham group); (2) an intestinal I/R group subjected to 1 h intestinal ischemia and 2 h reperfusion (I/R group); (3) a group treated with 20 mg/kg ginsenoside Rb1 before reperfusion (Rb1-20 group); and (4) a group treated with 40 mg/kg ginsenoside Rb1 before reperfusion (Rb1-40 group). Intestinal and lung histology was observed. The malondialdehyde (MDA) levels in intestinal tissues were measured. Myeloperoxidase (MPO), TNF-α, MDA levels, wet/dry weight ratio and immunohistochemical expression of intracellular adhesion molecule-1 (ICAM-1) in lung tissues were assayed. In addition, a western blot of lung NF-kB was performed. Results indicated that intestinal I/R induced intestinal and lung injury, which was characterized by increase of MDA levels and pathological scores in intestinal tissues and MPO, TNF-α , MDA levels, wet/dry weight ratio and ICAM-1, NF-kB expression in the lung tissues. Ginsenoside Rb1 (20, 40 mg/kg) ameliorated intestinal and lung injury, decreased MPO, TNF-α, MDA levels, wet/dry weight ratio, ICAM-1 and NF-kB expression in lung tissues. In conclusion, ginsenoside Rb1 ameliorated the lung injuries by decreasing the NF-kB activation-induced inflammatory response. Full article
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Open AccessArticle A New Phenolic Glycoside from Chamaecyparis obtusa var. breviramea f. crippsii
Molecules 2013, 18(1), 1255-1261; doi:10.3390/molecules18011255
Received: 19 November 2012 / Revised: 7 December 2012 / Accepted: 26 December 2012 / Published: 18 January 2013
Cited by 7 | PDF Full-text (235 KB)
Abstract
A new phenolic glycoside, 3-methoxyphenol 1-O-α-L-rhamnopyranosyl-(1→6)- O-β-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics [...] Read more.
A new phenolic glycoside, 3-methoxyphenol 1-O-α-L-rhamnopyranosyl-(1→6)- O-β-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics 211. Their structures were determined mainly by means of MS, 1D- and 2D-NMR data. Cytotoxicities of compounds 3 and 511 were tested on BGC-823, Hela and A549 cancer cell lines, the results showed that compound 8 was bioactive and its IC50 values were 6.9, 29.7 and 52.9 μM, respectively. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle A New Triterpenoid from Teucrium viscidum
Molecules 2013, 18(1), 1262-1269; doi:10.3390/molecules18011262
Received: 3 December 2012 / Revised: 1 January 2013 / Accepted: 7 January 2013 / Published: 21 January 2013
Cited by 8 | PDF Full-text (280 KB) | Supplementary Files
Abstract
A new ursane-type triterpenoid, 3β-hydroxy-urs-30-p-Z-hydroxycinnamoyloxy-12-en-28-oic-acid (1), together with three known triterpenoids, 3β-hydroxy-urs-30-p-E-hydroxycinnamoyloxy-12-en-28-oic-acid (2), 2α,3β,19α-trihydroxy-urs-12-en-28-oic-acid (3), and ursolic acid [...] Read more.
A new ursane-type triterpenoid, 3β-hydroxy-urs-30-p-Z-hydroxycinnamoyloxy-12-en-28-oic-acid (1), together with three known triterpenoids, 3β-hydroxy-urs-30-p-E-hydroxycinnamoyloxy-12-en-28-oic-acid (2), 2α,3β,19α-trihydroxy-urs-12-en-28-oic-acid (3), and ursolic acid (4), four known lignans, pinoresinol (5), 9α-hydroxypinoresinol (6), (+)-medioresinol (7), and (+)-kobusin (8), and two steroids, β-sitosterol (9), and daucosterol (10), were isolated from the whole parts of Teucrium viscidum. Their structures were established by a combination of spectroscopic data analysis, besides comparison with literature data. Compounds 14 were evaluated for their inhibitory activities against 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1). Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
Open AccessArticle Photochemical Synthesis and Properties of 1,6- and 1,8-Naphthalenophanes
Molecules 2013, 18(1), 1314-1324; doi:10.3390/molecules18011314
Received: 20 December 2012 / Revised: 9 January 2013 / Accepted: 15 January 2013 / Published: 21 January 2013
Cited by 3 | PDF Full-text (302 KB)
Abstract
Various 1,6- and 1,8-naphthalenophanes were synthesized by using the Photo-Dehydro-Diels-Alder (PDDA) reaction of bis-ynones. These compounds are easily accessible from w-(3-iodophenyl)carboxylic acids in three steps. The obtained naphthalenophanes are axially chiral and the activation barrier for the atropisomerization could be determined in [...] Read more.
Various 1,6- and 1,8-naphthalenophanes were synthesized by using the Photo-Dehydro-Diels-Alder (PDDA) reaction of bis-ynones. These compounds are easily accessible from w-(3-iodophenyl)carboxylic acids in three steps. The obtained naphthalenophanes are axially chiral and the activation barrier for the atropisomerization could be determined in some cases by means of dynamic NMR (DNMR) and/or dynamic HPLC (DHPLC) experiments. Full article
(This article belongs to the Special Issue New Trends in Photochemistry)
Open AccessArticle Chemical Constituents of Caesalpinia decapetala (Roth) Alston
Molecules 2013, 18(1), 1325-1336; doi:10.3390/molecules18011325
Received: 19 December 2012 / Revised: 19 December 2012 / Accepted: 20 December 2012 / Published: 22 January 2013
Cited by 19 | PDF Full-text (276 KB)
Abstract
The current study targets the chemical constituents of Caesalpinia decapetala (Roth) Alston and investigates the bioactivities of the isolated compounds. Fourteen known compounds were isolated using column chromatography, and structural identification was performed by physical and spectral analyses. The biological activities of [...] Read more.
The current study targets the chemical constituents of Caesalpinia decapetala (Roth) Alston and investigates the bioactivities of the isolated compounds. Fourteen known compounds were isolated using column chromatography, and structural identification was performed by physical and spectral analyses. The biological activities of the compounds were also evaluated by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2,2-diphenlyl-1-picrylhydrazyl (DPPH) assays. Emodin (6), baicalein (9), and apigenin (12) displayed antitumor activities against the MGC-803 cell line, while quercetin (2), rutin (5), baicalein (9), and epicatechin (13) showed stronger DPPH scavenging activities compared with ascorbic acid. Andrographolide (1), quercetin (2), bergenin (4), rutin (5), emodin (6), betulin (7), baicalein (9), polydatin (10), salicin (11), and apigenin (12), were obtained from C. decapetala (Roth) Alston for the first time. Full article
(This article belongs to the Section Natural Products)

Review

Jump to: Research

Open AccessReview Anti-Infectious Agents against MRSA
Molecules 2013, 18(1), 204-224; doi:10.3390/molecules18010204
Received: 16 October 2012 / Revised: 3 December 2012 / Accepted: 14 December 2012 / Published: 24 December 2012
Cited by 15 | PDF Full-text (770 KB)
Abstract
Clinically useful antibiotics, β-lactams and vancomycin, are known to inhibit bacterial cell wall peptidoglycan synthesis. Methicillin-resistant Staphylococcus aureus (MRSA) has a unique cell wall structure consisting of peptidoglycan and wall teichoic acid. In recent years, new anti-infectious agents (spirohexaline, tripropeptin C, DMPI, [...] Read more.
Clinically useful antibiotics, β-lactams and vancomycin, are known to inhibit bacterial cell wall peptidoglycan synthesis. Methicillin-resistant Staphylococcus aureus (MRSA) has a unique cell wall structure consisting of peptidoglycan and wall teichoic acid. In recent years, new anti-infectious agents (spirohexaline, tripropeptin C, DMPI, CDFI, cyslabdan, 1835F03, and BPH-652) targeting MRSA cell wall biosynthesis have been discovered using unique screening methods. These agents were found to inhibit important enzymes involved in cell wall biosynthesis such as undecaprenyl pyrophosphate (UPP) synthase, FemA, flippase, or UPP phosphatase. In this review, the discovery, the mechanism of action, and the future of these anti-infectious agents are described. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessReview Chiral Peptide Nucleic Acids with a Substituent in the N-(2-Aminoethy)glycine Backbone
Molecules 2013, 18(1), 287-310; doi:10.3390/molecules18010287
Received: 14 December 2012 / Revised: 19 December 2012 / Accepted: 19 December 2012 / Published: 27 December 2012
Cited by 18 | PDF Full-text (522 KB)
Abstract
A peptide nucleic acid (PNA) is a synthetic nucleic acid mimic in which the sugar-phosphate backbone is replaced by a peptide backbone. PNAs hybridize to complementary DNA and RNA with higher affinity and superior sequence selectivity compared to DNA. PNAs are resistant [...] Read more.
A peptide nucleic acid (PNA) is a synthetic nucleic acid mimic in which the sugar-phosphate backbone is replaced by a peptide backbone. PNAs hybridize to complementary DNA and RNA with higher affinity and superior sequence selectivity compared to DNA. PNAs are resistant to nucleases and proteases and have a low affinity for proteins. These properties make PNAs an attractive agent for biological and medical applications. To improve the antisense and antigene properties of PNAs, many backbone modifications of PNAs have been explored under the concept of preorganization. This review focuses on chiral PNAs bearing a substituent in the N-(2-aminoethyl)glycine backbone. Syntheses, properties, and applications of chiral PNAs are described. Full article
(This article belongs to the Special Issue Chemical Protein and Peptide Synthesis)
Open AccessReview Molecular Mechanism Underlying Anti-Inflammatory and Anti-Allergic Activities of Phytochemicals: An Update
Molecules 2013, 18(1), 322-353; doi:10.3390/molecules18010322
Received: 13 September 2012 / Revised: 6 December 2012 / Accepted: 14 December 2012 / Published: 27 December 2012
Cited by 36 | PDF Full-text (416 KB)
Abstract
The resort worldwide to edible medicinal plants for medical care has increased significantly during the last few years. Currently, there is a renewed interest in the search for new phytochemicals that could be developed as useful anti-inflammatory and anti-allergic agents to reduce [...] Read more.
The resort worldwide to edible medicinal plants for medical care has increased significantly during the last few years. Currently, there is a renewed interest in the search for new phytochemicals that could be developed as useful anti-inflammatory and anti-allergic agents to reduce the risk of many diseases. The activation of nuclear transcription factor-kappa B (NF-κB) has now been linked to a variety of inflammatory diseases, while data from numerous studies underline the importance of phytochemicals in inhibiting the pathway that activates this transcription factor. Moreover, the incidence of type I allergic disorders has been increasing worldwide, particularly, the hypersensitivity to food. Thus, a good number of plant products with anti-inflammatory and anti-allergic activity have been documented, but very few of these compounds have reached clinical use and there is scant scientific evidence that could explain their mode of action. Therefore, this paper intends to review the most salient recent reports on the anti-inflammatory and anti-allergic properties of phytochemicals and the molecular mechanisms underlying these properties. Full article
(This article belongs to the Section Natural Products)
Open AccessReview Semi-Synthesis of Labeled Proteins for Spectroscopic Applications
Molecules 2013, 18(1), 440-465; doi:10.3390/molecules18010440
Received: 28 November 2012 / Revised: 21 December 2012 / Accepted: 24 December 2012 / Published: 2 January 2013
Cited by 6 | PDF Full-text (1437 KB)
Abstract
Since the introduction of SPPS by Merrifield in the 60s, peptide chemists have considered the possibility of preparing large proteins. The introduction of native chemical ligation in the 90s and then of expressed protein ligation have opened the way to the preparation [...] Read more.
Since the introduction of SPPS by Merrifield in the 60s, peptide chemists have considered the possibility of preparing large proteins. The introduction of native chemical ligation in the 90s and then of expressed protein ligation have opened the way to the preparation of synthetic proteins without size limitations. This review focuses on semi-synthetic strategies useful to prepare proteins decorated with spectroscopic probes, like fluorescent labels and stable isotopes, and their biophysical applications. We show that expressed protein ligation, combining the advantages of organic chemistry with the easy and size limitless recombinant protein expression, is an excellent strategy for the chemical synthesis of labeled proteins, enabling a single protein to be functionalized at one or even more distinct positions with different probes. Full article
(This article belongs to the Special Issue Chemical Protein and Peptide Synthesis)
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Open AccessReview Access to Any Site Directed Stable Isotope (2H, 13C, 15N, 17O and 18O) in Genetically Encoded Amino Acids
Molecules 2013, 18(1), 482-519; doi:10.3390/molecules18010482
Received: 25 October 2012 / Revised: 10 December 2012 / Accepted: 24 December 2012 / Published: 2 January 2013
Cited by 2 | PDF Full-text (474 KB)
Abstract
Proteins and peptides play a preeminent role in the processes of living cells. The only way to study structure-function relationships of a protein at the atomic level without any perturbation is by using non-invasive isotope sensitive techniques with site-directed stable isotope incorporation [...] Read more.
Proteins and peptides play a preeminent role in the processes of living cells. The only way to study structure-function relationships of a protein at the atomic level without any perturbation is by using non-invasive isotope sensitive techniques with site-directed stable isotope incorporation at a predetermined amino acid residue in the protein chain. The method can be extended to study the protein chain tagged with stable isotope enriched amino acid residues at any position or combinations of positions in the system. In order to access these studies synthetic methods to prepare any possible isotopologue and isotopomer of the 22 genetically encoded amino acids have to be available. In this paper the synthetic schemes and the stable isotope enriched building blocks that are available via commercially available stable isotope enriched starting materials are described. Full article
(This article belongs to the Special Issue Chemical Protein and Peptide Synthesis)
Open AccessReview Crossed and Linked Histories of Tetrapyrrolic Macrocycles and Their Use for Engineering Pores within Sol-Gel Matrices
Molecules 2013, 18(1), 588-653; doi:10.3390/molecules18010588
Received: 26 October 2012 / Revised: 20 December 2012 / Accepted: 25 December 2012 / Published: 4 January 2013
Cited by 8 | PDF Full-text (1857 KB)
Abstract
The crossed and linked histories of tetrapyrrolic macrocycles, interwoven with new research discoveries, suggest that Nature has found in these structures a way to ensure the continuity of life. For diverse applications porphyrins or phthalocyanines must be trapped inside solid networks, but [...] Read more.
The crossed and linked histories of tetrapyrrolic macrocycles, interwoven with new research discoveries, suggest that Nature has found in these structures a way to ensure the continuity of life. For diverse applications porphyrins or phthalocyanines must be trapped inside solid networks, but due to their nature, these compounds cannot be introduced by thermal diffusion; the sol-gel method makes possible this insertion through a soft chemical process. The methodologies for trapping or bonding macrocycles inside pristine or organo-modified silica or inside ZrO2 xerogels were developed by using phthalocyanines and porphyrins as molecular probes. The sizes of the pores formed depend on the structure, the cation nature, and the identities and positions of peripheral substituents of the macrocycle. The interactions of the macrocyclic molecule and surface Si-OH groups inhibit the efficient displaying of the macrocycle properties and to avoid this undesirable event, strategies such as situating the macrocycle far from the pore walls or to exchange the Si-OH species by alkyl or aryl groups have been proposed. Spectroscopic properties are better preserved when long unions are established between the macrocycle and the pore walls, or when oligomeric macrocyclic species are trapped inside each pore. When macrocycles are trapped inside organo-modified silica, their properties result similar to those displayed in solution and their intensities depend on the length of the alkyl chain attached to the matrix. These results support the prospect of tuning up the pore size, surface area, and polarity inside the pore cavities in order to prepare efficient catalytic, optical, sensoring, and medical systems. The most important feature is that research would confirm again that tetrapyrrolic macrocycles can help in the development of the authentic pore engineering in materials science. Full article
(This article belongs to the Special Issue Tetrapyrroles, Porphyrins and Phthalocyanines)
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Open AccessReview Antioxidant Action and Therapeutic Efficacy of Allium sativum L.
Molecules 2013, 18(1), 690-700; doi:10.3390/molecules18010690
Received: 23 November 2012 / Revised: 14 December 2012 / Accepted: 28 December 2012 / Published: 4 January 2013
Cited by 33 | PDF Full-text (164 KB)
Abstract
Allium sativum (L.) is rich in antioxidants which help destroy free radicals particles that can damage cell membranes and DNA, and may contribute to the aging process as well as the development of a number of conditions, including heart disease and cancer. [...] Read more.
Allium sativum (L.) is rich in antioxidants which help destroy free radicals particles that can damage cell membranes and DNA, and may contribute to the aging process as well as the development of a number of conditions, including heart disease and cancer. Antioxidants neutralize free radicals and may reduce or even help prevent some of the damage they cause over time. The antioxidant activity of fresh Allium sativum L. (garlic) is well known and is mainly due to unstable and irritating organosulphur compounds. Fresh garlic extracted over a prolonged period (up to 20 months) produces odourless aged garlic extract (AGE) containing stable and water soluble organosulphur compounds that prevent oxidative damage by scavenging free radicals. The aim of this review was to understand the mechanism of antioxidant action and therapeutic efficacy of garlic. Full article
(This article belongs to the Special Issue Antioxidants 2012)
Open AccessReview Frontiers and Approaches to Chemical Synthesis of Oligodeoxyribonucleotides
Molecules 2013, 18(1), 1063-1075; doi:10.3390/molecules18011063
Received: 18 December 2012 / Revised: 9 January 2013 / Accepted: 11 January 2013 / Published: 15 January 2013
Cited by 8 | PDF Full-text (218 KB)
Abstract
The advantages and disadvantages of existing approaches to the synthesis of oligodeoxyribonucleotides (ODN) are discussed focusing on large-scale methods. The liquid phase and solid supported synthesis and the synthesis on soluble polymers are discussed. Different problems concerning the methods and implementation of [...] Read more.
The advantages and disadvantages of existing approaches to the synthesis of oligodeoxyribonucleotides (ODN) are discussed focusing on large-scale methods. The liquid phase and solid supported synthesis and the synthesis on soluble polymers are discussed. Different problems concerning the methods and implementation of the ODN synthesis are outlined depending on goals of using target oligomers. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessReview Evolution of Analysis of Polyhenols from Grapes, Wines, and Extracts
Molecules 2013, 18(1), 1076-1100; doi:10.3390/molecules18011076
Received: 18 December 2012 / Revised: 7 January 2013 / Accepted: 14 January 2013 / Published: 16 January 2013
Cited by 30 | PDF Full-text (588 KB)
Abstract
Grape and wine phenolics are structurally diverse, from simple molecules to oligomers and polymers usually designated as tannins. They have an important impact on the organoleptic properties of wines, that’s why their analysis and quantification are of primordial importance. The extraction of [...] Read more.
Grape and wine phenolics are structurally diverse, from simple molecules to oligomers and polymers usually designated as tannins. They have an important impact on the organoleptic properties of wines, that’s why their analysis and quantification are of primordial importance. The extraction of phenolics from grapes and from wines is the first step involved in the analysis. Then, several analytical methods have been developed for the determination of total content of phenolic, while chromatographic and spectrophotometric analyses are continuously improved in order to achieve adequate separation of phenolic molecules, their subsequent identification and quantification. This review provides a summary of evolution of analysis of polyphenols from grapes, wines and extracts. Full article
(This article belongs to the Special Issue Methods in Polyphenol Analysis)
Open AccessReview Suzuki-Miyaura Cross-Coupling in Acylation Reactions, Scope and Recent Developments
Molecules 2013, 18(1), 1188-1213; doi:10.3390/molecules18011188
Received: 19 December 2012 / Revised: 8 January 2013 / Accepted: 9 January 2013 / Published: 17 January 2013
Cited by 37 | PDF Full-text (472 KB)
Abstract
Since the first report and due to its handiness and wide scope, the Suzuki-Miyaura (SM) cross coupling reaction has become a routine methodology in many laboratories worldwide. With respect to other common transition metal catalyzed cross couplings, the SM reaction has been [...] Read more.
Since the first report and due to its handiness and wide scope, the Suzuki-Miyaura (SM) cross coupling reaction has become a routine methodology in many laboratories worldwide. With respect to other common transition metal catalyzed cross couplings, the SM reaction has been so far less exploited as a tool to introduce an acyl function into a specific substrate. In this review, the various approaches found in the literature will be considered, starting from the direct SM acylative coupling to the recent developments of cross coupling between boronates and acyl chlorides or anhydrides. Special attention will be dedicated to the use of masked acyl boronates, alkoxy styryl and alkoxy dienyl boronates as coupling partners. A final section will be then focused on the acyl SM reaction as key synthetic step in the framework of natural products synthesis. Full article
(This article belongs to the Special Issue Suzuki Reaction)
Open AccessReview A Review on Anti-Inflammatory Activity of Monoterpenes
Molecules 2013, 18(1), 1227-1254; doi:10.3390/molecules18011227
Received: 22 December 2012 / Revised: 4 January 2013 / Accepted: 5 January 2013 / Published: 18 January 2013
Cited by 40 | PDF Full-text (266 KB) | Supplementary Files
Abstract
Faced with the need to find new anti-inflammatory agents, great effort has been expended on the development of drugs for the treatment of inflammation. This disorder reduces the quality of life and overall average productivity, causing huge financial losses. In this review [...] Read more.
Faced with the need to find new anti-inflammatory agents, great effort has been expended on the development of drugs for the treatment of inflammation. This disorder reduces the quality of life and overall average productivity, causing huge financial losses. In this review the anti-inflammatory activity of 32 bioactive monoterpenes found in essential oils is discussed. The data demonstrate the pharmacological potential of this group of natural chemicals to act as anti-inflammatory drugs. Full article
(This article belongs to the Section Natural Products)
Open AccessReview Chemistry and Applications of Polysaccharide Solutions in Strong Electrolytes/Dipolar Aprotic Solvents: An Overview
Molecules 2013, 18(1), 1270-1313; doi:10.3390/molecules18011270
Received: 26 October 2012 / Revised: 2 January 2013 / Accepted: 9 January 2013 / Published: 21 January 2013
Cited by 10 | PDF Full-text (989 KB)
Abstract
Biopolymers and their derivatives are being actively investigated as substitutes for petroleum-based polymers. This has generated an intense interest in investigating new solvents, in particular for cellulose, chitin/chitosan, and starch. This overview focuses on recent advances in the dissolution and derivatization of [...] Read more.
Biopolymers and their derivatives are being actively investigated as substitutes for petroleum-based polymers. This has generated an intense interest in investigating new solvents, in particular for cellulose, chitin/chitosan, and starch. This overview focuses on recent advances in the dissolution and derivatization of these polysaccharides in solutions of strong electrolytes in dipolar aprotic solvents. A brief description of the molecular structures of these biopolymers is given, with emphases on the properties that are relevant to derivatization, namely crystallinity and accessibility. The mechanism of cellulose dissolution is then discussed, followed by a description of the strategies employed for the synthesis of cellulose derivatives (carboxylic acid esters, and ethers) under homogeneous reaction conditions. The same sequence of presentation has been followed for chitin/chitosan and starch. Future perspectives for this subject are summarized, in particular with regard to compliance with the principles of green chemistry. Full article
(This article belongs to the Special Issue Advances in Carbohydrate Chemistry 2012)
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