Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Molecules, Volume 16, Issue 6 (June 2011), Pages 4328-5314

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-73
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Biomolecule Profiles in Inedible Wild Mushrooms with Antioxidant Value
Molecules 2011, 16(6), 4328-4338; doi:10.3390/molecules16064328
Received: 4 May 2011 / Revised: 19 May 2011 / Accepted: 20 May 2011 / Published: 25 May 2011
Cited by 24 | PDF Full-text (211 KB)
Abstract
The use of natural products isolated from mushrooms, included inedible species, against infection, cancer diseases and other oxidative-stress related diseases is one of the cornerstones of modern medicine. In the present work, the antioxidant molecule profiles of inedible mushroom species were evaluated [...] Read more.
The use of natural products isolated from mushrooms, included inedible species, against infection, cancer diseases and other oxidative-stress related diseases is one of the cornerstones of modern medicine. In the present work, the antioxidant molecule profiles of inedible mushroom species were evaluated and compared with those of edible species. The order of antioxidant abundance found in inedible wild mushrooms was: phenolics > flavonoids > ascorbic acid > tocopherols > carotenoids, similar to that of edible species. Furthermore the same energetic biomolecules were found including the disaccharide trehalose, the monosaccharide alcohol derivative mannitol and the fatty acids palmitic, oleic and linoleic acids. Fomitopsis pinicola revealed a very high phenolics concentration (388 mg GAE/g extract) and powerful antioxidant properties, mainly reducing power (EC50 value 60 μg/mL similar to the standard Trolox®). It could find applications in the prevention of free radical-related diseases as a source of bioactive compounds. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Synthesis, Characterization, and Antimicrobial Evaluation of Oxadiazole Congeners
Molecules 2011, 16(6), 4339-4347; doi:10.3390/molecules16064339
Received: 13 April 2011 / Revised: 10 May 2011 / Accepted: 19 May 2011 / Published: 25 May 2011
Cited by 7 | PDF Full-text (176 KB)
Abstract
A series of 1,3-oxazole, 1,3-thiazole, isomeric 1,2,4-oxadiazole, 1,3,4-oxadiazole, and 1,2,3,4-tetrazole heterocycles was synthesized. All the compounds shared as a common feature the presence of a 4-hydroxyphenyl substituent. The structures of the synthesized compounds were confirmed by MS, 1H-NMR, and elemental analysis. [...] Read more.
A series of 1,3-oxazole, 1,3-thiazole, isomeric 1,2,4-oxadiazole, 1,3,4-oxadiazole, and 1,2,3,4-tetrazole heterocycles was synthesized. All the compounds shared as a common feature the presence of a 4-hydroxyphenyl substituent. The structures of the synthesized compounds were confirmed by MS, 1H-NMR, and elemental analysis. In vitro antimicrobial activity for all the newly synthesized compounds at concentrations of 200-25 μg/mL was evaluated against Gram+ve organisms such as methicillin-resistant Staphylococcus aureus (MRSA), Gram–ve organisms such as Escherichia coli (E. coli), and the fungal strain Aspergillus niger (A. niger) by the cup plate method. Ofloxacin and ketoconazole (10 μg/mL) were used as reference standards for antibacterial and antifungal activity, respectively. Compounds 15, 16, and 20 showed notable antibacterial and antifungal activities at higher concentrations (200 μg/mL), whereas 17-19 were found to display significant antibacterial or antifungal activity (25-50 μg/mL) against the Gram+ve, Gram–ve bacteria, or fungal cells used in the present study. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Three New Cycloartenol Triterpenoid Saponins from the Roots of Cimicifuga simplex Wormsk
Molecules 2011, 16(6), 4348-4357; doi:10.3390/molecules16064348
Received: 3 May 2011 / Revised: 23 May 2011 / Accepted: 23 May 2011 / Published: 25 May 2011
Cited by 7 | PDF Full-text (196 KB)
Abstract
Three new cycloartenol triterpene saponins, named shengmaxinsides A-C, have been isolated from the ethyl acetate soluble fraction of an ethanol extract of Cimicifuga simplex Wormsk roots. Their structures were established by chemical tests and detailed spectroscopic analysis as 25-O-acetyl-7,8-didehydrocimigenol-3-O-β [...] Read more.
Three new cycloartenol triterpene saponins, named shengmaxinsides A-C, have been isolated from the ethyl acetate soluble fraction of an ethanol extract of Cimicifuga simplex Wormsk roots. Their structures were established by chemical tests and detailed spectroscopic analysis as 25-O-acetyl-7,8-didehydrocimigenol-3-O-β-D-galactopyranoside (1), 7,8-didehydrocimigenol-3-O-β-D-galactopyranoside (2) and 7,8-didehydro-24S-O-acetylhydroshengmanol-3-O-β-D-galactopyranoside (3), respectively. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Halomonas sp. OKOH—A Marine Bacterium Isolated from the Bottom Sediment of Algoa Bay—Produces a Polysaccharide Bioflocculant: Partial Characterization and Biochemical Analysis of Its Properties
Molecules 2011, 16(6), 4358-4370; doi:10.3390/molecules16064358
Received: 23 March 2011 / Revised: 19 May 2011 / Accepted: 20 May 2011 / Published: 25 May 2011
Cited by 18 | PDF Full-text (318 KB)
Abstract
A bioflocculant-producing bacterium isolated from seawater was identified based on 16S rRNA gene nucleotide sequence to have 99% similarity to that of Halomonas sp. Au160H and the nucleotide sequence was deposited as Halomonas sp. OKOH (Genbank accession number is HQ875722). Influences of [...] Read more.
A bioflocculant-producing bacterium isolated from seawater was identified based on 16S rRNA gene nucleotide sequence to have 99% similarity to that of Halomonas sp. Au160H and the nucleotide sequence was deposited as Halomonas sp. OKOH (Genbank accession number is HQ875722). Influences of carbon source, nitrogen source, salt ions and pH on flocculating activity were investigated. The bioflocculant was optimally produced when glucose (87% flocculating activity) and urea (88% flocculating activity) were used as sources of carbon and nitrogen, respectively. Also, initial pH of 7.0 and Ca2+ supported optimal production of the bioflocculant with flocculating activities of 87% respectively. Chemical analyses revealed the bioflocculant to be a polysaccharide. Full article
Open AccessCommunication Platycoside O, a New Triterpenoid Saponin from the Roots of Platycodon grandiflorum
Molecules 2011, 16(6), 4371-4378; doi:10.3390/molecules16064371
Received: 25 March 2011 / Revised: 13 May 2011 / Accepted: 18 May 2011 / Published: 26 May 2011
Cited by 9 | PDF Full-text (196 KB)
Abstract
A new unusual minor triterpenoid saponin, platycoside O (1), was isolated from the 75% EtOH extract obtained from the roots of Platycodon grandiflorum, together with four known saponins: platycoside M-3 (2), platycoside J (3), platycoside [...] Read more.
A new unusual minor triterpenoid saponin, platycoside O (1), was isolated from the 75% EtOH extract obtained from the roots of Platycodon grandiflorum, together with four known saponins: platycoside M-3 (2), platycoside J (3), platycoside F (4) and platycoside B (5). The structure of 1 was determined as 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-2β,3β,16α,23-tetrahydroxyolean-12-en-24-methoxyl, 24-oxo-28-oic acid 28-O-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside on the basis of spectral analysis and chemical evidence. Full article
Open AccessArticle Knoevenagel Reaction in [MMIm][MSO4]: Synthesis of Coumarins
Molecules 2011, 16(6), 4379-4388; doi:10.3390/molecules16064379
Received: 26 April 2011 / Revised: 18 May 2011 / Accepted: 19 May 2011 / Published: 27 May 2011
Cited by 22 | PDF Full-text (174 KB)
Abstract
The ionic liquid 1,3-dimethylimidazolium methyl sulfate, [MMIm][MSO4], together with a small amount of water (the amount taken up by the ionic liquid upon exposure to air), acts efficiently as both solvent and catalyst of the Knoevenagel condensation reactions of malononitrile [...] Read more.
The ionic liquid 1,3-dimethylimidazolium methyl sulfate, [MMIm][MSO4], together with a small amount of water (the amount taken up by the ionic liquid upon exposure to air), acts efficiently as both solvent and catalyst of the Knoevenagel condensation reactions of malononitrile with 4-substituted benzaldehydes, without the need for any other solvent or promoter, affording yields of 92%–99% within 2–7 min at room temperature. When L-proline is used as an additional promoter to obtain coumarins from o-hydroxybenzaldehydes, the reaction also proceeds in high yields. Work-up is very simple and the ionic liquid can be reused several times. Some of the coumarins obtained are described for the first time. Full article
Figures

Open AccessArticle In Vitro and In Vivo Antitumor Activity of Scutellaria barbate Extract on Murine Liver Cancer
Molecules 2011, 16(6), 4389-4400; doi:10.3390/molecules16064389
Received: 24 March 2011 / Revised: 10 May 2011 / Accepted: 23 May 2011 / Published: 27 May 2011
Cited by 18 | PDF Full-text (625 KB)
Abstract
In the present study, we investigated the in vitro and in vivo antitumor effects of crude extract of Scutellaria barbate (CE-SB) on mouse hepatoma H22 cells. The MTT assay was used to determine the growth inhibition of H22 cells in vitro. [...] Read more.
In the present study, we investigated the in vitro and in vivo antitumor effects of crude extract of Scutellaria barbate (CE-SB) on mouse hepatoma H22 cells. The MTT assay was used to determine the growth inhibition of H22 cells in vitro. The in vivo therapeutic effects of CE-SB were determined using H22 tumor bearing mice. Besides, the body weight, tumor weight, thymus index and spleen index of H22 bearing mice were also measured. The tumor inhibitory rate (IR) was calculated according to the mean weight of tumor (MWT). The phagocytotic function of macrophages was examined by observing peritoneal macrophages phagocytize chicken RBC. The results showed that CE-SB could inhibit the growth of hepatoma H22 Cells in vitro and in vivo. Furthermore, CE-SB could improve immune function of H22 tumor bearing mice. Together these results indicate that CE-SB has antitumor activity and seems to be safe and effective for the use of anti-tumor therapy. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Two New Acridone Alkaloids from Glycosmis macrantha
Molecules 2011, 16(6), 4401-4407; doi:10.3390/molecules16064401
Received: 24 February 2011 / Revised: 9 May 2011 / Accepted: 16 May 2011 / Published: 27 May 2011
Cited by 5 | PDF Full-text (194 KB)
Abstract
Extraction and chromatographic separation of the extracts of dried stem barks of Glycosmis macrantha lead to isolation of two new acridone alkaloids, macranthanine (1) and 7-hydroxynoracronycine (2), and a known acridone, atalaphyllidine (3). The structures of [...] Read more.
Extraction and chromatographic separation of the extracts of dried stem barks of Glycosmis macrantha lead to isolation of two new acridone alkaloids, macranthanine (1) and 7-hydroxynoracronycine (2), and a known acridone, atalaphyllidine (3). The structures of these alkaloids were determined by detailed spectral analysis and also by comparison with reported data. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Microwave-Assisted Extraction of Polyphenols from Camellia oleifera Fruit Hull
Molecules 2011, 16(6), 4428-4437; doi:10.3390/molecules16064428
Received: 24 March 2011 / Revised: 9 May 2011 / Accepted: 25 May 2011 / Published: 27 May 2011
Cited by 19 | PDF Full-text (315 KB)
Abstract
The abundant fruit hulls of tea-oil tree (Camellia oleifera) are still underutilized and wastefully discaded to pollute the environment. In order to solve this problem and better utilize the fruit hulls of C. oleifera, a microwave-assisted extraction system was [...] Read more.
The abundant fruit hulls of tea-oil tree (Camellia oleifera) are still underutilized and wastefully discaded to pollute the environment. In order to solve this problem and better utilize the fruit hulls of C. oleifera, a microwave-assisted extraction system was used to extract their polyphenols using water as the extraction solvent. A central composite design (CCD) was used to monitor the effects of three extraction processing parameters – liquid:solid ratio (mL/g), extraction time (min) and extraction temperature (°C) – on the polyphenol yield (%). The results showed that the optimal conditions were liquid:solid ratio of 15.33:1 (mL/g), extraction time of 35 min and extraction temperature of 76 °C. Validation tests indicated that under the optimized conditions the actual yield of polyphenols was 15.05 ± 0.04% with RSD = 0.21% (n = 5), which was in good agreement with the predicted yield. Phenolic compounds in the extracts were analysed by HPLC, and gallic acid was found to be the predominant constituent. The total flavonoid content in the extracts was determined and high total flavonoid content was revealed (140.06 mg/g dry material). Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Phytochemical Analysis and Antimicrobial Activities of Methanolic Extracts of Leaf, Stem and Root from Different Varieties of Labisa pumila Benth
Molecules 2011, 16(6), 4438-4450; doi:10.3390/molecules16064438
Received: 14 March 2011 / Revised: 2 May 2011 / Accepted: 4 May 2011 / Published: 27 May 2011
Cited by 39 | PDF Full-text (186 KB)
Abstract
A local herb, Kacip Fatimah, is famous amongst Malay women for its uses in parturition; however, its phytochemical contents have not been fully documented. Therefore, a study was performed to evaluate the phenolics, flavonoids, and total saponin contents, and antibacterial and antifungal [...] Read more.
A local herb, Kacip Fatimah, is famous amongst Malay women for its uses in parturition; however, its phytochemical contents have not been fully documented. Therefore, a study was performed to evaluate the phenolics, flavonoids, and total saponin contents, and antibacterial and antifungal properties of the leaf, stem and root of three varieties of Labisia pumila Benth. Total saponins were found to be higher in the leaves of all three varieties, compared to the roots and stems. Leaves of var. pumila exhibited significantly higher total saponin content than var. alata and lanceolata, with values of 56.4, 43.6 and 42.3 mg diosgenin equivalent/g dry weight, respectively. HPLC analyses of phenolics and flavonoids in all three varieties revealed the presence of gallic acid, caffeic acid, rutin, and myricetin in all plant parts. Higher levels of flavonoids (rutin, quercitin, kaempferol) were observed in var. pumila compared with alata and lanceolata, whereas higher accumulation of phenolics (gallic acid, pyrogallol) was recorded in var. alata, followed by pumila and lanceolata. Antibacterial activities of leaf, stem and root extracts of all varieties determined against both Gram positive (Micrococcus luteus, Bacillus subtilis B145, Bacillus cereus B43, Staphylococcus aureus S1431) and Gram negative (Enterobacter aerogenes, Klebsiella pneumonia K36, Escherichia coli E256, Pseudomonas aeruginosa PI96) pathogens showed that crude methanolic extracts are active against these bacteria at low concentrations, albeit with lower antibacterial activity compared to kanamycin used as the control. Antifungal activity of methanolic extracts of all plant parts against Fusarium sp., Candida sp. and Mucor using the agar diffusion disc exhibited moderate to appreciable antifungal activities compared to streptomycin used as positive control. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Bismuth Modified Carbon-Based Electrodes for the Determination of Selected Neonicotinoid Insecticides
Molecules 2011, 16(6), 4451-4466; doi:10.3390/molecules16064451
Received: 4 April 2011 / Revised: 19 May 2011 / Accepted: 24 May 2011 / Published: 27 May 2011
Cited by 25 | PDF Full-text (822 KB)
Abstract
Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE) and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential [...] Read more.
Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE) and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential pulse voltammetric (DPV) mode was applied to determine clothianidin in the concentration range from 2.5 to 23 μg cm−3 with a relative standard deviation (RSD) not exceeding 1.5%. The tricresyl phosphate-based carbon paste electrodes (TCP-CPEs), bulk modified with 5 and 20 w/w% of bismuth, showed a different analytical performance in the determination of imidacloprid, regarding the peak shape, potential window, and noise level. The TCP-CPE with 5% Bi was advantageous, and the developed DPV method based on it allowed the determination in the concentration range from 1.7 to 60 μg cm−3 with an RSD of 2.4%. To get a deeper insight into the morphology of the bismuth-based sensor surfaces, scanning electron microscopic measurements were performed of both the surface film and the bulk modified electrodes. Full article
Open AccessArticle A Novel Thiophene-Fused Polycyclic Aromatic with a Tetracene Core: Synthesis, Characterization, Optical and Electrochemical Properties
Molecules 2011, 16(6), 4467-4481; doi:10.3390/molecules16064467
Received: 9 May 2011 / Revised: 25 May 2011 / Accepted: 25 May 2011 / Published: 27 May 2011
Cited by 5 | PDF Full-text (964 KB)
Abstract
FeCl3-mediated oxidative cyclization was successfully used to construct an extended thiophene-pendant pyrene skeleton and synthesize a novel thiophene-fused polycyclic aromatic (THTP-C) with a tetracene core. The identity of the compound was confirmed by 1H-NMR, 13C-NMR, MS, and elemental [...] Read more.
FeCl3-mediated oxidative cyclization was successfully used to construct an extended thiophene-pendant pyrene skeleton and synthesize a novel thiophene-fused polycyclic aromatic (THTP-C) with a tetracene core. The identity of the compound was confirmed by 1H-NMR, 13C-NMR, MS, and elemental analysis. Meanwhile, a single crystal of THTP-C was obtained and analyzed by X-ray single-crystal diffraction. THTP-C has a “saddle” shaped π-conjugated 1-D supramolecular structure, and favors highly ordered self-assembly by π-π interactions as evidenced by its concentration-dependent 1H-NMR spectra in solution. The optical properties of THTP-C were investigated by ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy and its electrochemical properties were investigated by cyclic voltammetry (CV). The relatively large band gap (2.86 eV), low EHOMO level (−5.64 eV) and intermolecular π-π interactions imply that THTP-C has a high stability against photo-degradation and oxidation, and may be a promising candidate for stable hole-transporting materials. Full article
Open AccessArticle Pharmaceutical Composition of Hydrochlorothiazide:β-Cyclo-dextrin: Preparation by Three Different Methods, Physico-Chemical Characterization and In Vivo Diuretic Activity Evaluation
Molecules 2011, 16(6), 4482-4499; doi:10.3390/molecules16064482
Received: 29 April 2011 / Revised: 19 May 2011 / Accepted: 23 May 2011 / Published: 27 May 2011
Cited by 11 | PDF Full-text (595 KB)
Abstract
Hydrochlorothiazide is a common diuretic antihypertensive drug of the thiazide family. Its poor aqueous solubility is one of the reasons for its limited bioavailability after oral administration. This work aimed at the development of a hydrochlorothiazide:β-cyclodextrin (HTZ:β-CD) pharmaceutical composition in order to [...] Read more.
Hydrochlorothiazide is a common diuretic antihypertensive drug of the thiazide family. Its poor aqueous solubility is one of the reasons for its limited bioavailability after oral administration. This work aimed at the development of a hydrochlorothiazide:β-cyclodextrin (HTZ:β-CD) pharmaceutical composition in order to improve water solubility and bioavailability of the drug. The HTZ:β-CD complexes were prepared by three different methods: spray-drying, freeze-drying and fluid bed. Complexes were characterized by thermal analysis, Fourier transform-infrared (FTIR) spectroscopy, powder X-ray diffractometry, NMR (2D-ROESY), scanning electron microscopy (SEM), particle analysis and intrinsic dissolution. The findings reveal that three binary systems prepared presented better solubility results in comparison with free HTZ. Increased diuretic effect was observed to HTZ:β-CD obtained by fluid bed in comparison to free drug in rats. Results taken together suggest that pharmacological effect of HTZ in complex was increased by solubility improvement promoted by cyclodextrin. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Catalytic Synthesis of α-Oxoketene S,S-Acetals in a Wet Ionic Liquid [Bmim]Cl/H2O Homogeneous System
Molecules 2011, 16(6), 4500-4510; doi:10.3390/molecules16064500
Received: 23 March 2011 / Revised: 11 May 2011 / Accepted: 18 May 2011 / Published: 27 May 2011
Cited by 2 | PDF Full-text (237 KB)
Abstract
A clean, practical and environmentally friendly synthesis in a homogeneous system has been developed for α-oxoketene S,S-acetals. A mixture of [Bmim]Cl and water was used as medium. The best economical and practical molar ratio of [Bmim]Cl to substrate was 4 to [...] Read more.
A clean, practical and environmentally friendly synthesis in a homogeneous system has been developed for α-oxoketene S,S-acetals. A mixture of [Bmim]Cl and water was used as medium. The best economical and practical molar ratio of [Bmim]Cl to substrate was 4 to 1. With various types of 1,3-dicarbonyl compounds as substrate, the corresponding α-oxoketene S,S-acetals have been prepared under mild reaction conditions with yields of 53–74% after purification with silica gel column. [Bmim]Cl/water can be recycled several times. Full article
Figures

Open AccessArticle Synthesis and Antimalarial Activity of Novel Dihydro-Artemisinin Derivatives
Molecules 2011, 16(6), 4527-4538; doi:10.3390/molecules16064527
Received: 18 April 2011 / Revised: 20 May 2011 / Accepted: 24 May 2011 / Published: 30 May 2011
Cited by 14 | PDF Full-text (284 KB)
Abstract
The Plasmodium falciparum cysteine protease falcipain-2, one of the most promising targets for antimalarial drug design, plays a key role in parasite survival as a major peptide hydrolase within the hemoglobin degradation pathway. In this work, a series of novel dihydroartemisinin derivatives [...] Read more.
The Plasmodium falciparum cysteine protease falcipain-2, one of the most promising targets for antimalarial drug design, plays a key role in parasite survival as a major peptide hydrolase within the hemoglobin degradation pathway. In this work, a series of novel dihydroartemisinin derivatives based on (thio)semicarbazone scaffold were designed and synthesized as potential falcipain-2 inhibitors. The in vitro biological assay indicated that most of the target compounds showed excellent inhibition activity against P. falciparum falcipain-2, with IC50 values in the 0.29–10.63 μM range. Molecular docking studies were performed to investigate the binding affinities and interaction modes for the inhibitors. The preliminary SARs were summarized and could serve as a foundation for further investigation in the development of antimalarial drugs. Full article
Open AccessArticle Phytochemical and Cytotoxic Investigations of Curcuma mangga Rhizomes
Molecules 2011, 16(6), 4539-4548; doi:10.3390/molecules16064539
Received: 29 March 2011 / Revised: 18 April 2011 / Accepted: 20 April 2011 / Published: 31 May 2011
Cited by 17 | PDF Full-text (170 KB)
Abstract
Investigations on the cytotoxic effects of the crude methanol and fractionated extracts (hexane, ethyl acetate) C. mangga against six human cancer cell lines, namely the hormone-dependent breast cell line (MCF-7), nasopharyngeal epidermoid cell line (KB), lung cell line (A549), cervical cell line [...] Read more.
Investigations on the cytotoxic effects of the crude methanol and fractionated extracts (hexane, ethyl acetate) C. mangga against six human cancer cell lines, namely the hormone-dependent breast cell line (MCF-7), nasopharyngeal epidermoid cell line (KB), lung cell line (A549), cervical cell line (Ca Ski), colon cell lines (HCT 116 and HT-29), and one non-cancer human fibroblast cell line (MRC-5) were conducted using an in-vitro neutral red cytotoxicity assay. The crude methanol and fractionated extracts (hexane and ethyl acetate) displayed good cytotoxic effects against MCF-7, KB, A549, Ca Ski and HT-29 cell lines, but exerted no damage on the MRC-5 line. Chemical investigation from the hexane and ethyl acetate fractions resulted in the isolation of seven pure compounds, namely (E)-labda-8(17),12-dien-15,16-dial (1), (E)-15,16-bisnor-labda-8(17),11-dien-13-on (2), zerumin A (3), β-sitosterol, curcumin, demethoxycurcumin and bis-demethoxycurcumin. Compounds 1 and 3 exhibited high cytotoxic effects against all six selected cancer cell lines, while compounds 2 showed no anti-proliferative activity on the tested cell lines. Compound 1 also demonstrated strong cytotoxicity against the normal cell line MRC-5. This paper reports for the first time the cytotoxic activities of C. mangga extracts on KB, A549, Ca Ski, HT-29 and MRC-5, and the occurrence of compound 2 and 3 in C. mangga. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Microwave Assisted Synthesis and Unusual Coupling of Some Novel Pyrido[3,2-f][1,4]thiazepines
Molecules 2011, 16(6), 4549-4559; doi:10.3390/molecules16064549
Received: 23 March 2011 / Revised: 7 May 2011 / Accepted: 25 May 2011 / Published: 31 May 2011
Cited by 8 | PDF Full-text (197 KB)
Abstract
3-Amino-3-thioxopropanamide (1) reacted with ethyl acetoacetate to form 6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide (2), which reacted with α-haloketones 3 to produce 2,3-disubstituted-8-hydroxy-6-methyl-2H,5H-pyrido[3,2-f]-[1,4]thiazepin-5-ones 4a-c. Benzoylation of 4c led to the formation of the dibenzoate derivative 9. Compounds 4a-c could be prepared [...] Read more.
3-Amino-3-thioxopropanamide (1) reacted with ethyl acetoacetate to form 6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide (2), which reacted with α-haloketones 3 to produce 2,3-disubstituted-8-hydroxy-6-methyl-2H,5H-pyrido[3,2-f]-[1,4]thiazepin-5-ones 4a-c. Benzoylation of 4c led to the formation of the dibenzoate derivative 9. Compounds 4a-c could be prepared stepwise through the formation of S-alkylated derivatives 10a-c. Compounds 2, 4a-c, 9 and 10a-c were prepared using microwave as a source of heat, and gave better yields in shorter times than those achieved by traditional methods. Coupling of 4a-c with arenediazonium chlorides proceeded unusually to give the 6-hydroxy-4-methyl-2-(arylazo)thieno[2,3-b]pyridin-3(2H)-one ring contraction products 14. Structures of the newly synthesized compounds were proven by spectral and chemical methods. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Open AccessCommunication Altholactone Displays Promising Antimicrobial Activity
Molecules 2011, 16(6), 4560-4566; doi:10.3390/molecules16064560
Received: 4 March 2011 / Revised: 9 May 2011 / Accepted: 19 May 2011 / Published: 3 June 2011
Cited by 4 | PDF Full-text (189 KB)
Abstract
The antimicrobial activity of altholactone, a naturally extracted styryllactone isolated from Goniothalamus malayanus, was determined against Gram positive (S. aureus ATTC 25923, S. aureus ATTC 25392, and E. faecalis ATTC 29212) and Gram negative (E. coli ATTC 35218, S. [...] Read more.
The antimicrobial activity of altholactone, a naturally extracted styryllactone isolated from Goniothalamus malayanus, was determined against Gram positive (S. aureus ATTC 25923, S. aureus ATTC 25392, and E. faecalis ATTC 29212) and Gram negative (E. coli ATTC 35218, S. typhi ATTC 14023 and P. aeruginosa ATCC 27853) reference bacteria and against the fungus C. albicans ATTC 10231. Different concentrations of altholactone (0, 12, 25, and 50 μg/mL) were used. Results revealed that altholactone inhibited the growth of all tested microbes except P. aeruginosa ATCC 27853 in a dose-dependant manner, with the highest cytotoxic effects occuring at 50 μg/mL. The average of the inhibition zones of the different concentrations was between 0–30 mm. Furthermore, altholactone-induced antimicrobial activity against the more sensitive microbes was assessed by measuring the minimal inhibitory concentration (MIC). Results indicated that Gram positive (S. aureus ATTC 25923, S. aureus ATTC 25392, and E. faecalis ATTC 29212) cells were more sensitive to altholactone than Gram negative ones (E. coli ATTC 35218, S. typhi ATTC 14023). C. albicans showed moderate sensitivity. These results indicate that altholactone might be a potential antimicrobial agent, particularly in ciprofloxacin-refractory S. aureus and E. faecalis infections. Further investigations are required to illustrate the mechanism(s) by which altholactone produces its antimicrobial effects. Full article
Open AccessArticle Fluorescent Probes Detecting the Phagocytic Phase of Apoptosis: Enzyme-Substrate Complexes of Topoisomerase and DNA
Molecules 2011, 16(6), 4599-4614; doi:10.3390/molecules16064599
Received: 28 April 2011 / Revised: 20 May 2011 / Accepted: 24 May 2011 / Published: 3 June 2011
Cited by 9 | PDF Full-text (529 KB)
Abstract
In apoptosis, the initial self-driven suicide phase generates cellular corpses which are digested in the phagolysosomes of professional and amateur phagocytes during the subsequent waste-management phase. This ensures the complete elimination of the genetic material which often contains pathological, viral or cancerous [...] Read more.
In apoptosis, the initial self-driven suicide phase generates cellular corpses which are digested in the phagolysosomes of professional and amateur phagocytes during the subsequent waste-management phase. This ensures the complete elimination of the genetic material which often contains pathological, viral or cancerous DNA sequences. Although the phagocytic phase is critical for the efficient execution of apoptosis, there are currently few methods specifically adapted for its detailed visualization in the fixed tissue section format. To resolve this we developed new fluorescent probes for in situ research. The probes selectively visualize active phagocytic cells of any lineage (professional, amateur phagocytes or surrounding tissue cells) which engulf and digest apoptotic cell DNA. These fluorescent probes are the covalently-bound enzyme-DNA intermediates produced in a topoisomerase reaction with specific “starting” oligonucleotides. They detect a specific marker of DNase II cleavage activity, which occurs exclusively in phagolysosomes of the cells that engulfed apoptotic nuclei. The probes provide snap-shot images of the digestion process occurring in cellular organelles responsible for the actual execution of phagocytic degradation of apoptotic cell corpses. We applied the probes for visualization of the phagocytic reaction in tissue sections of normal thymus and in several human lymphomas. We also discuss the nature, stability and properties of DNase II-type breaks as a marker of phagocytic activity. This development provides a useful fluorescent tool for studies of pathologies where clearance of dying cells is essential, such as cancers, inflammation, infection and auto-immune disorders. Full article
Open AccessArticle A High Molar Extinction Coefficient Mono-Anthracenyl Bipyridyl Heteroleptic Ruthenium(II) Complex: Synthesis, Photophysical and Electrochemical Properties
Molecules 2011, 16(6), 4615-4631; doi:10.3390/molecules16064615
Received: 27 April 2011 / Revised: 31 May 2011 / Accepted: 1 June 2011 / Published: 3 June 2011
Cited by 10 | PDF Full-text (360 KB)
Abstract
In our quest to develop good materials as photosensitizers for photovoltaic dye-sensitized solar cells (DSSCs), cis-dithiocyanato-4-(2,3-dimethylacrylic acid)-2,2'-bipyridyl-4-(9-anthracenyl-(2,3-dimethylacrylic)-2,2'-bipyridyl ruthenium(II) complex, a high molar extinction coefficient charge transfer sensitizer, was designed, synthesized and characterized by spectroscopy and electrochemical techniques. Earlier studies on heteroleptic [...] Read more.
In our quest to develop good materials as photosensitizers for photovoltaic dye-sensitized solar cells (DSSCs), cis-dithiocyanato-4-(2,3-dimethylacrylic acid)-2,2'-bipyridyl-4-(9-anthracenyl-(2,3-dimethylacrylic)-2,2'-bipyridyl ruthenium(II) complex, a high molar extinction coefficient charge transfer sensitizer, was designed, synthesized and characterized by spectroscopy and electrochemical techniques. Earlier studies on heteroleptic ruthenium(II) complex analogues containing functionalized oligo-anthracenyl phenanthroline ligands have been reported and documented. Based on a general linear correlation between increase in the length of π-conjugation bond and the molar extinction coefficients, herein, we report the photophysical and electrochemical properties of a Ru(II) bipyridyl complex analogue with a single functionalized anthracenyl unit. Interestingly, the complex shows better broad and intense metal-to ligand charge transfer (MLCT) band absorption with higher molar extinction coefficient (λmax = 518 nm, e = 44900 M−1cm−1), and appreciable photoluminescence spanning the visible region than those containing higher anthracenyl units. It was shown that molar absorption coefficient of the complexes may not be solely depended on the extended π-conjugation but are reduced by molecular aggregation in the molecules. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle New Catechol Derivatives of Safrole and Their Antiproliferative Activity towards Breast Cancer Cells
Molecules 2011, 16(6), 4632-4641; doi:10.3390/molecules16064632
Received: 13 April 2011 / Revised: 31 May 2011 / Accepted: 2 June 2011 / Published: 3 June 2011
Cited by 7 | PDF Full-text (191 KB)
Abstract
Catechols were synthesized from safrole. Nine derivatives were prepared and assessed for antiproliferative effects using different human cell lines. The in vitro growth inhibition assay was based on the sulphorhodamine dye to quantify cell viability. The derivatives 4-allylbenzene-1,2-diol (3), 4 [...] Read more.
Catechols were synthesized from safrole. Nine derivatives were prepared and assessed for antiproliferative effects using different human cell lines. The in vitro growth inhibition assay was based on the sulphorhodamine dye to quantify cell viability. The derivatives 4-allylbenzene-1,2-diol (3), 4 4-[3-(acetyloxy)propyl]-1,2-phenylene diacetate (6) and 4-[3-(acetyloxy)propyl]-5-nitro-1,2-phenylene diacetate (10) showed higher cytotoxicity than the parent compound 2 in tests performed on two breast cancer cell lines (MCF-7 and MDA-MB-231). The IC50 values of 40.2 ± 6.9 μM, 5.9 ± 0.8 μM and 33.8 ± 4.9 μM, respectively, were obtained without toxicity towards dermal human fibroblast (DHF cells). Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Triterpenoids from the Roots of Sanguisorba tenuifolia var. Alba
Molecules 2011, 16(6), 4642-4651; doi:10.3390/molecules16064642
Received: 15 April 2011 / Revised: 26 May 2011 / Accepted: 27 May 2011 / Published: 3 June 2011
Cited by 10 | PDF Full-text (233 KB)
Abstract
The ethyl acetate soluble fraction from the roots of Sanguisorba tenuifolia was found to have a hypoglucemic effect in alloxan-induced diabetic rats. Two new triterpenoids, identified as 2-oxo-3β,19α-dihydroxyolean-12-en-28-oic acid β-D-gluco-pyranosyl ester (1) and 2α,19 [...] Read more.
The ethyl acetate soluble fraction from the roots of Sanguisorba tenuifolia was found to have a hypoglucemic effect in alloxan-induced diabetic rats. Two new triterpenoids, identified as 2-oxo-3β,19α-dihydroxyolean-12-en-28-oic acid β-D-gluco-pyranosyl ester (1) and 2α,19α-dihydroxy-3-oxo-12-ursen-28-oic acid β-D-glucopyranosyl ester (4) were isolated from this fraction, along with thirteen known triterpenoids. Their structures were elucidated by chemical and spectroscopic methods. All these compounds demonstrated inhibitory activities against α-glucosidase with IC50 values in the 0.62-3.62 mM range. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle On the π Coordination of Organometallic Fullerene Complexes
Molecules 2011, 16(6), 4652-4659; doi:10.3390/molecules16064652
Received: 29 April 2011 / Revised: 26 May 2011 / Accepted: 27 May 2011 / Published: 3 June 2011
Cited by 5 | PDF Full-text (486 KB)
Abstract
Novel organometallic complexes of fullerene C80 and aryl ligands were simulated. The nature and characteristics of this family of complexes involving π coordination between the fullerene and a metal centre have been studied from a theoretical point of view. We are [...] Read more.
Novel organometallic complexes of fullerene C80 and aryl ligands were simulated. The nature and characteristics of this family of complexes involving π coordination between the fullerene and a metal centre have been studied from a theoretical point of view. We are particularly interested in complexes where η6 coordination is present, this being the strangest manifestation of known coordinations, and thus we have studied several known and simulated compounds of this kind in order to understand the lack of examples. The presence of other η6 or η5 ligands on the opposite side seems to be an important element aiding the stabilization of these complexes, also inducing the conductive and semiconductive behaviour of the studied species. Full article
(This article belongs to the Special Issue Organometallic Chemistry)
Open AccessArticle Synthesis and Antifungal Evaluation of 1-Aryl-2-dimethyl-aminomethyl-2-propen-1-one Hydrochlorides
Molecules 2011, 16(6), 4660-4671; doi:10.3390/molecules16064660
Received: 15 March 2011 / Revised: 27 May 2011 / Accepted: 31 May 2011 / Published: 3 June 2011
Cited by 7 | PDF Full-text (175 KB)
Abstract
The development of resistance to current antifungal therapeutics drives the search for new effective agents. The fact that several acetophenone-derived Mannich bases had shown remarkable antifungal activities in our previous studies led us to design and synthesize some acetophenone-derived Mannich bases, 1-8 [...] Read more.
The development of resistance to current antifungal therapeutics drives the search for new effective agents. The fact that several acetophenone-derived Mannich bases had shown remarkable antifungal activities in our previous studies led us to design and synthesize some acetophenone-derived Mannich bases, 1-8 and 2-acetylthiophene-derived Mannich base 9, 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochloride, to evaluate their antifungal activities. The designed chemical structures have α,β-unsaturated ketone moieties, which are responsible for the bioactivities of the Mannich bases. The aryl part was C6H5 (1); 4-CH3C6H4 (2); 4-CH3OC6H4 (3); 4-ClC6H4 (4); 4-FC6H4 (5); 4-BrC6H4 (6); 4-HOC6H4 (7); 4-NO2C6H4 (8); and C4H3S(2-yl) (9). In this study the designed compounds were synthesized by the conventional heating method and also by the microwave irradiation method to compare these methods in terms of reaction times and yields to find an optimum synthetic method, which can be applied for the synthesis of Mannich bases in further studies. Since there are limited number of studies reporting the synthesis of Mannich bases by microwave irradiation, this study may also contribute to the general literature on Mannich bases. Compound 7 was reported for the first time. Antifungal activities of all compounds and synthesis of the compounds by microwave irradiation were also reported for the first time by this study. Fungi (15 species) were used for antifungal activity test. Amphotericin B was tested as an antifungal reference compound. In conclusion, compounds 1-6, and 9, which had more potent (2–16 times) antifungal activity than the reference compound amphotericin B against some fungi, can be model compounds for further studies to develop new antifungal agents. In addition, microwave irradiation can be considered to reduce reaction period, while the conventional method can still be considered to obtain compounds with higher reaction yields in the synthesis of new Mannich bases. Full article
(This article belongs to the Special Issue Prodrugs)
Open AccessArticle Determining Optimum Conditions for Lipase-Catalyzed Synthesis of Triethanolamine (TEA)-Based Esterquat Cationic Surfactant by a Taguchi Robust Design Method
Molecules 2011, 16(6), 4672-4680; doi:10.3390/molecules16064672
Received: 12 April 2011 / Revised: 3 May 2011 / Accepted: 4 May 2011 / Published: 3 June 2011
Cited by 14 | PDF Full-text (255 KB)
Abstract
A Taguchi robust design method with an L9 orthogonal array was implemented to optimize experimental conditions for the biosynthesis of triethanolamine (TEA)-based esterquat cationic surfactants using an enzymatic reaction method. The esterification reaction conversion% was considered as the response. Enzyme amount, [...] Read more.
A Taguchi robust design method with an L9 orthogonal array was implemented to optimize experimental conditions for the biosynthesis of triethanolamine (TEA)-based esterquat cationic surfactants using an enzymatic reaction method. The esterification reaction conversion% was considered as the response. Enzyme amount, reaction time, reaction temperature and molar ratio of substrates, [oleic acid: triethanolamine (OA:TEA)] were chosen as main parameters. As a result of the Taguchi analysis in this study, the molar ratio of substrates was found to be the most influential parameter on the esterification reaction conversion%. The amount of enzyme in the reaction had also a significant effect on reaction conversion%. Full article
Open AccessArticle The 2-(Triphenylsilyl)ethoxycarbonyl-(“Tpseoc”-) Group: A New Silicon-Based, Fluoride Cleavable Oxycarbonyl Protecting Group Highly Orthogonal to the Boc-, Fmoc- and Cbz-Groups
Molecules 2011, 16(6), 4695-4718; doi:10.3390/molecules16064695
Received: 29 April 2011 / Revised: 30 May 2011 / Accepted: 31 May 2011 / Published: 7 June 2011
PDF Full-text (354 KB)
Abstract
Starting from 2-(triphenylsilyl)ethanol a new oxycarbonyl protecting group cleavable by fluoride ion induced Peterson-elimination has been developed. Known 2-(triphenylsilyl)ethanol has been prepared from commercially available triphenylvinyl-silane by a hydroboration-oxidation sequence using the sterically hindered borane reagent 9-BBN. The silyl alcohol was subsequently transformed into its chloroformate, imidazolylcarboxylic acid ester and p-nitrophenyl carbonate and used in standard protocols for the formation of carbamates and carbonates. The Tpseoc group proved to be highly resistant against acidic conditions applied in removal of tert-butyl esters and the t-Boc-group. It also withstood catalytic hydrogenation, treatment with morpholine, methylhydrazine and Pd-reagents/allyl-scavanger combinations, conditions required to cleave Cbz-, Fmoc-, phthalimide- and Alloc-groups. The Tpseoc-group is cleaved upon treatment with TBAF/CsF at 0 °C or r.t. with cleavage times reaching from < 10 min. to 24 h. Its orthogonality, ease of cleavage and UV-detectability makes the Tpseoc-group a promising alternative to other widely used silicon based amine protecting groups like the Teoc- and SES-groups. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Monasnicotinates A–D, Four New Pyridine Alkaloids from the Fungal Strain Monascus pilosus BCRC 38093
Molecules 2011, 16(6), 4719-4727; doi:10.3390/molecules16064719
Received: 4 May 2011 / Revised: 30 May 2011 / Accepted: 31 May 2011 / Published: 7 June 2011
Cited by 6 | PDF Full-text (242 KB)
Abstract
Four new pyridine derivatives, monasnicotinates A–D (14) were isolated from the red yeast rice of Monascus pilosus BCRC 38093. Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry. Their [...] Read more.
Four new pyridine derivatives, monasnicotinates A–D (14) were isolated from the red yeast rice of Monascus pilosus BCRC 38093. Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry. Their inhibitory effects on NO production was also evaluated. Full article
Figures

Open AccessArticle Antioxidant Capacity and Phenolic Content of Caesalpinia pyramidalis Tul. and Sapium glandulosum (L.) Morong from Northeastern Brazil
Molecules 2011, 16(6), 4728-4739; doi:10.3390/molecules16064728
Received: 24 March 2011 / Revised: 30 April 2011 / Accepted: 24 May 2011 / Published: 7 June 2011
Cited by 10 | PDF Full-text (176 KB)
Abstract
The aims of this study were to quantify the phenolic content and evaluate the antioxidant potential of extracts from the bark and leaves of C. pyramidalis and S. glandulosum. The total phenolic content (TPC) and total tannin content (TTC) were determined [...] Read more.
The aims of this study were to quantify the phenolic content and evaluate the antioxidant potential of extracts from the bark and leaves of C. pyramidalis and S. glandulosum. The total phenolic content (TPC) and total tannin content (TTC) were determined using the Folin-Ciocalteu method, and the total flavonoids content (TFC) was measured via complexation with aluminum chloride. The antioxidant activity was evaluated with DPPH (2.2-diphenyl-1-picrylhydrazyl) and FIC (ferrous ion chelating) assays. The TPC ranged between 135.55 ± 9.85 and 459.79 ± 11.65 tannic acid equivalents (TAE) in mg/g material (mg TAE/g). The leaves of both species contained high levels of tannins and flavonoids. The crude ethanol extracts (CEE) from the bark of C. pyramidalis showed high antioxidant activity when compared to ascorbic acid and rutin, whereas the CEE from the leaves was more efficient in chelating ferrous ions. C. pyramidalis had very high phenolic content and anti-radical activity, which indicates a need for further studies aimed at the purification and identification of compounds responsible for the antioxidant activity. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Synthesis of Gentiooligosaccharides of Genistein and Glycitein and Their Radical Scavenging and Anti-Allergic Activity
Molecules 2011, 16(6), 4740-4747; doi:10.3390/molecules16064740
Received: 19 April 2011 / Revised: 27 May 2011 / Accepted: 2 June 2011 / Published: 7 June 2011
PDF Full-text (168 KB)
Abstract
The synthesis of gentiooligosaccharides of genistein and glycitein using cultured cells of Eucalyptus perriniana as biocatalysts was investigated. The cells of E. perriniana glycosylated genistein and glycitein to give the corresponding 4'-O-b-glucosides, 7-O-b-glucosides, and [...] Read more.
The synthesis of gentiooligosaccharides of genistein and glycitein using cultured cells of Eucalyptus perriniana as biocatalysts was investigated. The cells of E. perriniana glycosylated genistein and glycitein to give the corresponding 4'-O-b-glucosides, 7-O-b-glucosides, and 7-O-b-gentiobiosides, which were two new compounds. The b-glucosides of genistein and glycitein showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity and superoxide-radical scavenging activity. On the other hand, 7-O-b-glucosides of genistein and glycitein and the 7-O-b-gentiobioside of glycitein exerted inhibitory effects on IgE antibody production. Full article
(This article belongs to the Special Issue Radical Chemistry)
Open AccessArticle Design and Synthesis of a Dual Linker for Solid Phase Synthesis of Oleanolic Acid Derivatives
Molecules 2011, 16(6), 4748-4763; doi:10.3390/molecules16064748
Received: 23 May 2011 / Revised: 27 May 2011 / Accepted: 30 May 2011 / Published: 8 June 2011
Cited by 4 | PDF Full-text (315 KB)
Abstract
A hydrophilic amino-terminated poly(ethylene glycol)-type dual linker for solid phase synthesis of oleanolic acid derivatives using trityl chloride resin was designed and synthesized for the first time. Model reactions in both liquid and solid phase were performed to show the feasibility of [...] Read more.
A hydrophilic amino-terminated poly(ethylene glycol)-type dual linker for solid phase synthesis of oleanolic acid derivatives using trityl chloride resin was designed and synthesized for the first time. Model reactions in both liquid and solid phase were performed to show the feasibility of its selective cleavage at two different sites. The biological assay results indicated that the long and flexible alkyl ether functionality in the linker is less likely to be critical for the binding event. Following the successful solid-phase synthesis of model compounds, the potential of this dual linker in reaction monitoring and target identification is deemed worthy of further study. Full article
Open AccessArticle Synthesis and Antimicrobial Activity of Some Novel 5-Alkyl-6-Substituted Uracils and Related Derivatives
Molecules 2011, 16(6), 4764-4774; doi:10.3390/molecules16064764
Received: 13 May 2011 / Revised: 31 May 2011 / Accepted: 1 June 2011 / Published: 8 June 2011
Cited by 9 | PDF Full-text (143 KB) | Supplementary Files
Abstract
6-Chloro-5-ethyl-, n-propyl- and isopropyluracils 5a-c were efficiently prepared from the corresponding 5-alkybarbituric acids 3a-c via treatment with phosphorus oxychloride and N,N-dimethylaniline to yield the corresponding 5-alkyl-2,4,6-trichloro-pyrimidines 4a-c, which were selectively hydrolyzed [...] Read more.
6-Chloro-5-ethyl-, n-propyl- and isopropyluracils 5a-c were efficiently prepared from the corresponding 5-alkybarbituric acids 3a-c via treatment with phosphorus oxychloride and N,N-dimethylaniline to yield the corresponding 5-alkyl-2,4,6-trichloro-pyrimidines 4a-c, which were selectively hydrolyzed by heating in 10% aqueous sodium hydroxide for 30 minutes. The reaction of compounds 5a-c with 1-substituted piperazines yielded the corresponding 5-alkyl-6-(4-substituted-1-piperazinyl)uracils 6a-j. The target 8-alkyltetrazolo[1,5-f]pyrimidine-5,7(3H,6H)-diones 7a-c were prepared via the reaction of 5a-c with sodium azide. Compounds 6a-j and 7a-c were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compound 6h displayed potent broad-spectrum antibacterial activity, while compound 6b showed moderate activity against the Gram-positive bacteria. All the tested compounds were practically inactive against Candida albicans. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Biologically Important Eremophilane Sesquiterpenes from Alaska Cedar Heartwood Essential Oil and Their Semi-Synthetic Derivatives
Molecules 2011, 16(6), 4775-4785; doi:10.3390/molecules16064775
Received: 11 April 2011 / Revised: 28 May 2011 / Accepted: 30 May 2011 / Published: 8 June 2011
Cited by 5 | PDF Full-text (173 KB)
Abstract
The essential oil of Alaska cedar heartwood is known to contain compounds which contribute to the remarkable durability of this species. While previous research has identified several compounds, a complete description of this oil has not been undertaken. In this research a [...] Read more.
The essential oil of Alaska cedar heartwood is known to contain compounds which contribute to the remarkable durability of this species. While previous research has identified several compounds, a complete description of this oil has not been undertaken. In this research a profile of the oil is given in which the major components are identified by GC, isolation and spectroscopic techniques. The major components of the steam distilled essential oil were identified as nootkatin, nootkatone, valencene, nootaktene, carvacrol, methyl carvacrol, nootkatol (2), and eremophil-1(10),11-dien-13-ol (3). The last two compounds were isolated for the first time from Alaska cedar in this research. The absolute stereochemistry at C-2 of nootkatol was shown to have the (S) configuration using the Mosher ester method. Assignment of stereochemistry for valencene-13-ol (3) was established by synthesis from valencene (6). Finally, two related sesquiterpenoids were synthesized from nootkatone and valencene. These sesquiterpenoids were nootkatone-1,10-11,12-diepoxide (5) and valencene-13-aldehyde (4), respectively. Full article
Open AccessArticle Synthesis and In Vitro Antiproliferative Activity of Novel Androst-5-ene Triazolyl and Tetrazolyl Derivatives
Molecules 2011, 16(6), 4786-4806; doi:10.3390/molecules16064786
Received: 12 May 2011 / Revised: 2 June 2011 / Accepted: 6 June 2011 / Published: 9 June 2011
Cited by 20 | PDF Full-text (258 KB)
Abstract
A straightforward and reliable method for the regioselective synthesis of steroidal 1,4-disubstituted triazoles and 1,5-disubstituted tetrazoles via copper(I)-catalyzed cycloadditions is reported. Heterocycle moieties were efficiently introduced onto the starting azide compound 3β-acetoxy-16β-azidomethylandrost-5-en-17β-ol through use of the “click” chemistry approach. The antiproliferative activities [...] Read more.
A straightforward and reliable method for the regioselective synthesis of steroidal 1,4-disubstituted triazoles and 1,5-disubstituted tetrazoles via copper(I)-catalyzed cycloadditions is reported. Heterocycle moieties were efficiently introduced onto the starting azide compound 3β-acetoxy-16β-azidomethylandrost-5-en-17β-ol through use of the “click” chemistry approach. The antiproliferative activities of the newly-synthesized triazoles were determined in vitro on three human gynecological cell lines (HeLa, MCF7 and A2780) using the microculture tetrazolium assay. Full article
Open AccessArticle Lichtheimia blakesleeana as a New Potencial Producer of Phytase and Xylanase
Molecules 2011, 16(6), 4807-4817; doi:10.3390/molecules16064807
Received: 19 May 2011 / Revised: 7 June 2011 / Accepted: 8 June 2011 / Published: 9 June 2011
Cited by 6 | PDF Full-text (295 KB)
Abstract
Brazil is known for its great potential for production of renewable resources such as agro-industrial residues. These residues can be used as alternative sources of new products. Meanwhile, solid-state fermentation, with its advantages of energy conservation and pollution reduction, has been identified [...] Read more.
Brazil is known for its great potential for production of renewable resources such as agro-industrial residues. These residues can be used as alternative sources of new products. Meanwhile, solid-state fermentation, with its advantages of energy conservation and pollution reduction, has been identified as a process of great potential for the production of bioactive compounds, especially enzymes. In the present work, a 23 factorial design was used to evaluate the effects of pH, temperature and moisture on the production of phytase and xylanase by Lichtheimia blakesleeana URM 5604 through the fermentation of citrus pulp. Statistical analyses of the results showed that the only the pH influenced the production of these enzymes, with the best phytase production (264.68 U/g) ocurring at pH 6.0, 34 °C, initial moisture 50%, after 48 hours of culture. The best conditions for xylanase production (397.82 U/g) were fermentation for 120 hours at pH 4.0, 26 °C and initial moisture of 70%. The best parameters for the simultaneous production of phytase (226.92 U/g) and xylanase (215.59 U/g) were determined to be initial moisture of 50%, pH 6.0, 26 °C, and 48 hours of fermentation. Full article
Open AccessArticle Effects of Fractionation and Combinatorial Evaluation of Tamarindus indica Fractions for Antibacterial Activity
Molecules 2011, 16(6), 4818-4827; doi:10.3390/molecules16064818
Received: 28 April 2011 / Revised: 7 June 2011 / Accepted: 8 June 2011 / Published: 9 June 2011
Cited by 4 | PDF Full-text (179 KB)
Abstract
Six fractions, named TiA – TiF, were obtained by fractionating the crude ethanol extract of the stem bark of Tamarindus indica using column chromatographic techniques. On TLC, fraction TiB showed five bands, TiC three bands, while TiD and TiE showed two bands [...] Read more.
Six fractions, named TiA – TiF, were obtained by fractionating the crude ethanol extract of the stem bark of Tamarindus indica using column chromatographic techniques. On TLC, fraction TiB showed five bands, TiC three bands, while TiD and TiE showed two bands each. TiC, TiD and TiE were re-eluted with different solvent systems to yield two fractions each, while TiB yielded four. These subfractions were designated B1-B4; C1-C2; D1-D2 and E1-E2, respectively. Tannins, flavonoids and alkaloids, among other components, were detected, albeit in different proportions with respect to fractions and subfractions and were compartmentalized with respect to the solvent systems used. The in vitro antibacterial activity of fractions and subfractions was tested separately and in combinations using the agar well diffusion technique. The susceptibly of test strains (expressed as %) were: 83.3% (TiA and TiB), 75.0% (crude extract and TiC), 66.7% (TiD), 50.0% (TiE) and 16.7% (TiF) when used singly, whereas in combination, the corresponding susceptibilities were 100% (CE), 83.3% (DE), 66.7% (AB, AF, BC, BD, DE and EF), 50% (AC and CD), 33.3% (BE and BF) and 16.7% (AD) against Gram negative bacteria strains and 100% (EF), 80% (DE), 60% (AB, BC and CE), 40% (AC, BD, BF, CF and DF) and 20% (AE, AF, BE and CD) against Gram positive strains. Percentage susceptibility with combinatorial use of re-fractions ranged from 85.7–57.1% and 60–40% against Gram negative and positive strains (TiB subfractions), respectively, 100–85.7% and 40–0% against Gram negative and positive strains (TiC, TiD and TiE sub-fractions). Full article
Open AccessArticle Flavonoids from Praxelis clematidea R.M. King and Robinson Modulate Bacterial Drug Resistance
Molecules 2011, 16(6), 4828-4835; doi:10.3390/molecules16064828
Received: 12 May 2011 / Revised: 2 June 2011 / Accepted: 7 June 2011 / Published: 10 June 2011
Cited by 19 | PDF Full-text (250 KB)
Abstract
Chemical studies of Praxelis clematidea R.M. King & Robinson resulted in the isolation of six flavones: Apigenine, genkwanine, 7,4’-dimethylapigenin, trimethylapigenin,cirsimaritin and tetramethylscutellarein, which were tested for their toxicity against Staphylococcus aureus SA-1199B, a strain possessing the NorA efflux pump. Efflux pumps are integral proteins of the bacterial membrane and are recognized as one of the main causes of bacterial drug resistance, since they expel antibiotics from the cell. The inhibition of this transporter is one form of modulating bacterial resistance to antimicrobial drugs. The flavones tested did not show any significant antibacterial activity against the Staphylococcus aureus strain used, but were able to modulate bacterial drug resistance. This property might be related to the degree of lipophilicity of the flavones conferred by the methoxyl groups, since 4’,5,6,7 tetramethoxyflavone the most methoxylated compound, reduced the minimal inhibitory concentration of the drug 16-fold. Full article
Open AccessArticle The Immuno-Regulatory Effects of Schisandra chinensis and Its Constituents on Human Monocytic Leukemia Cells
Molecules 2011, 16(6), 4836-4849; doi:10.3390/molecules16064836
Received: 19 April 2011 / Revised: 7 June 2011 / Accepted: 9 June 2011 / Published: 10 June 2011
Cited by 9 | PDF Full-text (943 KB)
Abstract
Many diseases occur when the immune system is weakened. Intracellular signals activate immuno-responsive cells to produce cytokines that modulate the immune response. Schisandra chinensis has been used traditionally to treat general fatigue, neurasthenia, and spontaneous sweating. In the present study, the effect [...] Read more.
Many diseases occur when the immune system is weakened. Intracellular signals activate immuno-responsive cells to produce cytokines that modulate the immune response. Schisandra chinensis has been used traditionally to treat general fatigue, neurasthenia, and spontaneous sweating. In the present study, the effect of constituents of S. chinensis on cytokine release by human monocytic leukemia cells (THP-1) was tested using microparticle-based flow cytometric analysis. Two major lignans, schizandrin (Sch) and gomisin A (Gom A), were identified and shown to induce interleukin (IL)-8, macrophage inflammatory protein-1β (MIP-1β), and granulocyte-macrophage-colony stimulating factor (GM-CSF) release by THP-1 cells. By reverse transcription polymerase chain reaction (RT-PCR) or quantitative real-time PCR, there was a dose-dependent increase of IL-8, MIP-1β and GM-CSF mRNA levels. Thus, Sch and Gom A from S. chinensis enhance cytokine release by THP-1 cells and this effect occurs through mRNA upregulation. Upregulation of MIP-1β and GM-CSF in particular may have clinical applications. Therefore, S. chinensis may be therapeutically beneficial by promoting humoral and cell-mediated immune responses. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Synthetic Studies on Bioactive Natural Polyketides: Intramolecular Nitrile Oxide-Olefin Cycloaddition Approach for Construction of a Macrolactone Skeleton of Macrosphelide B
Molecules 2011, 16(6), 4850-4860; doi:10.3390/molecules16064850
Received: 27 April 2011 / Revised: 26 May 2011 / Accepted: 7 June 2011 / Published: 10 June 2011
Cited by 5 | PDF Full-text (366 KB)
Abstract
Studies on the synthesis of macrosphelide B via an intramolecular nitrile oxide-olefin cycloaddition (INOC) is described. In particular, an asymmetric INOC approach using phase transfer catalysts seems to be a potentially efficient and versatile procedure for the construction of the macrolactone skeleton [...] Read more.
Studies on the synthesis of macrosphelide B via an intramolecular nitrile oxide-olefin cycloaddition (INOC) is described. In particular, an asymmetric INOC approach using phase transfer catalysts seems to be a potentially efficient and versatile procedure for the construction of the macrolactone skeleton of macrosphelide B in terms of facial selectivity. Our preliminary and unprecedented stereoselective procedure is anticipated to be usefully applied through further studies for the synthesis of the macrosphelide family. Full article
(This article belongs to the Special Issue Polyketide)
Open AccessArticle Comparison of Compositions and Antimicrobial Activities of Essential Oils from Chemically Stimulated Agarwood, Wild Agarwood and Healthy Aquilaria sinensis (Lour.) Gilg Trees
Molecules 2011, 16(6), 4884-4896; doi:10.3390/molecules16064884
Received: 17 March 2011 / Revised: 7 June 2011 / Accepted: 8 June 2011 / Published: 14 June 2011
Cited by 35 | PDF Full-text (252 KB)
Abstract
The composition and antimicrobial activity of the essential oils which were obtained from agarwood originated from Aquilaria sinensis (Lour.) Gilg stimulated by the chemical method (S1) were characterized, taking wild agarwood (S2) and healthy trees (S3) respectively as the positive and negative [...] Read more.
The composition and antimicrobial activity of the essential oils which were obtained from agarwood originated from Aquilaria sinensis (Lour.) Gilg stimulated by the chemical method (S1) were characterized, taking wild agarwood (S2) and healthy trees (S3) respectively as the positive and negative controls. The chemical composition of S1 was investigated by gas chromatography-mass spectrometry (GC-MS). The essential oil of S1 showed a similar composition to that of S2, being rich in sesquiterpenes and aromatic constituents. However, the essential oil of S3 was abundant in fatty acids and alkanes. Essential oils of S1 and S2 had better inhibition activities towards Bacillus subtilis and Staphyloccus aureus, compared with essential oil of S3. Escherichia coli was not sensitive to any of them. Full article
Open AccessArticle Synthesis and In Vitro Protein Tyrosine Kinase Inhibitory Activity of Furan-2-yl(phenyl)methanone Derivatives
Molecules 2011, 16(6), 4897-4911; doi:10.3390/molecules16064897
Received: 27 April 2011 / Revised: 1 June 2011 / Accepted: 7 June 2011 / Published: 14 June 2011
Cited by 4 | PDF Full-text (237 KB)
Abstract
A series of novel furan-2-yl(phenyl)methanone derivatives were synthesized, and their structures were established on the basis of 1H-NMR, 13C-NMR and mass spectral data. All the prepared compounds were screened for their in vitro protein tyrosine kinase inhibitory activity and several [...] Read more.
A series of novel furan-2-yl(phenyl)methanone derivatives were synthesized, and their structures were established on the basis of 1H-NMR, 13C-NMR and mass spectral data. All the prepared compounds were screened for their in vitro protein tyrosine kinase inhibitory activity and several new derivatives exhibited promising activity, which, in some cases, was identical to, or even better than that of genistein, a positive reference compound. The preliminary structure-activity relationships of these compounds were investigated and are discussed. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessCommunication Directed Formation of DNA Nanoarrays through Orthogonal Self-Assembly
Molecules 2011, 16(6), 4912-4922; doi:10.3390/molecules16064912
Received: 4 May 2011 / Revised: 31 May 2011 / Accepted: 10 June 2011 / Published: 15 June 2011
Cited by 11 | PDF Full-text (2447 KB) | Supplementary Files
Abstract
We describe the synthesis of terpyridine modified DNA strands which selectively form DNA nanotubes through orthogonal hydrogen bonding and metal complexation interactions. The short DNA strands are designed to self-assemble into long duplexes through a sticky-end approach. Addition of weakly binding metals [...] Read more.
We describe the synthesis of terpyridine modified DNA strands which selectively form DNA nanotubes through orthogonal hydrogen bonding and metal complexation interactions. The short DNA strands are designed to self-assemble into long duplexes through a sticky-end approach. Addition of weakly binding metals such as Zn(II) and Ni(II) induces the formation of tubular arrays consisting of DNA bundles which are 50-200 nm wide and 2-50 nm high. TEM shows additional long distance ordering of the terpy-DNA complexes into fibers. Full article
(This article belongs to the Special Issue Nucleoside Analogues)
Figures

Open AccessArticle Derivatives of 10,16-Dihydroxyhexadecanoic Acid Isolated from Tomato (Solanum lycopersicum) as Potential Material for Aliphatic Polyesters
Molecules 2011, 16(6), 4923-4936; doi:10.3390/molecules16064923
Received: 6 May 2011 / Revised: 1 June 2011 / Accepted: 10 June 2011 / Published: 15 June 2011
Cited by 7 | PDF Full-text (177 KB) | Supplementary Files
Abstract
The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (or 10,16-dihydroxypalmitic acid; 10,16-DHPA), was isolated and used to efficiently synthesize two different monomers (16-hydroxy-10-oxo-hexadecanoic and 7-oxohexa-decanedioic acids) in addition to a dimer and linear and branched trimers. These compounds were fully characterized using [...] Read more.
The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (or 10,16-dihydroxypalmitic acid; 10,16-DHPA), was isolated and used to efficiently synthesize two different monomers (16-hydroxy-10-oxo-hexadecanoic and 7-oxohexa-decanedioic acids) in addition to a dimer and linear and branched trimers. These compounds were fully characterized using NMR and MS techniques and could be used as starting materials for the synthesis of a wide range of chemicals and bio-polyesters, particularly the latter due to their physical properties, non-toxicity, and relative abundance among raw materials. Full article
(This article belongs to the Section Molecular Diversity)
Figures

Open AccessArticle Microwave Assisted Synthesis of Some New Fused 1,2,4-Triazines Bearing Thiophene Moieties With Expected Pharmacological Activity
Molecules 2011, 16(6), 4937-4957; doi:10.3390/molecules16064937
Received: 1 April 2011 / Revised: 25 May 2011 / Accepted: 3 June 2011 / Published: 15 June 2011
Cited by 25 | PDF Full-text (298 KB)
Abstract
Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones, 1,3,4-thiadiazolo[2,3-c][1,2,4]triazinone and pyrazolo[5,1-c]-[1,2,4]triazine-7-carbonitrile, have been synthesized by treatment of 1 with bifunctional [...] Read more.
Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones, 1,3,4-thiadiazolo[2,3-c][1,2,4]triazinone and pyrazolo[5,1-c]-[1,2,4]triazine-7-carbonitrile, have been synthesized by treatment of 1 with bifunctional oxygen and halogen compounds, CS2/KOH and malononitrile via heterocyclization reactions, in addition to some uncondensed triazines. Structures of the products have been deduced from their elemental analysis and spectral data (IR, 1H-NMR, 13C-NMR). Select new synthesized compounds were screened as anticancer agents, with some showing activity as cytotoxic agents against different cancer cell lines. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Figures

Open AccessArticle Anti-Migration Effects of Gekko Sulfated Glycopeptide on Human Hepatoma SMMC-7721 Cells
Molecules 2011, 16(6), 4958-4970; doi:10.3390/molecules16064958
Received: 30 May 2011 / Revised: 11 June 2011 / Accepted: 14 June 2011 / Published: 16 June 2011
Cited by 9 | PDF Full-text (2005 KB)
Abstract
Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Previous studies showed that the Gekko sulfated polysaccharide-protein complex suppressed the proliferation and migration of hepatoma cells. Gekko sulfated glycopeptide α was obtained from [...] Read more.
Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Previous studies showed that the Gekko sulfated polysaccharide-protein complex suppressed the proliferation and migration of hepatoma cells. Gekko sulfated glycopeptide α was obtained from Gekko sulfated polysaccharide-protein complex using papain hydrolysis. Gekko sulfated glycopeptide α inhibited the proliferation and migration of SMMC-7721 cells. The secretion of IL-8 and the concentration of intracellular calcium were decreased after Gekko sulfated glycopeptide α exposure. SMMC-7721 cells in the control group showed abnormal features, with a polygonal shape, whereas this changed to a spindle shape after the treatment with Gekko sulfated glycopeptide α. Actin filaments were distributed diffusely along the cell membrane in control cells, whereas those were polymerized and preferentially accumulated in the cytoplasm of treated cells. Microtubules distributed in the cytoplasm of untreated cells were located diffusely whereas those in treated cells were polymerized. Therefore, Gekko sulfated glycopeptide α inhibit the migration of hepatoma cells via reducing the secretion of IL-8 and the concentration of intracellular calcium, as well as regulating the reorganization of cytoskeleton. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Epitope Prediction Based on Random Peptide Library Screening: Benchmark Dataset and Prediction Tools Evaluation
Molecules 2011, 16(6), 4971-4993; doi:10.3390/molecules16064971
Received: 28 February 2011 / Revised: 1 June 2011 / Accepted: 10 June 2011 / Published: 16 June 2011
Cited by 12 | PDF Full-text (279 KB) | Supplementary Files
Abstract
Epitope prediction based on random peptide library screening has become a focus as a promising method in immunoinformatics research. Some novel software and web-based servers have been proposed in recent years and have succeeded in given test cases. However, since the number [...] Read more.
Epitope prediction based on random peptide library screening has become a focus as a promising method in immunoinformatics research. Some novel software and web-based servers have been proposed in recent years and have succeeded in given test cases. However, since the number of available mimotopes with the relevant structure of template-target complex is limited, a systematic evaluation of these methods is still absent. In this study, a new benchmark dataset was defined. Using this benchmark dataset and a representative dataset, five examples of the most popular epitope prediction software products which are based on random peptide library screening have been evaluated. Using the benchmark dataset, in no method did performance exceed a 0.42 precision and 0.37 sensitivity, and the MCC scores suggest that the epitope prediction results of these software programs are greater than random prediction about 0.09–0.13; while using the representative dataset, most of the values of these performance measures are slightly improved, but the overall performance is still not satisfactory. Many test cases in the benchmark dataset cannot be applied to these pieces of software due to software limitations. Moreover chances are that these software products are overfitted to the small dataset and will fail in other cases. Therefore finding the correlation between mimotopes and genuine epitope residues is still far from resolved and much larger dataset for mimotope-based epitope prediction is desirable. Full article
Open AccessArticle Effects of Acute Gamma Irradiation on Physiological Traits and Flavonoid Accumulation of Centella asiatica
Molecules 2011, 16(6), 4994-5007; doi:10.3390/molecules16064994
Received: 8 April 2011 / Revised: 21 May 2011 / Accepted: 1 June 2011 / Published: 17 June 2011
Cited by 13 | PDF Full-text (218 KB)
Abstract
In the present study, two accessions of Centella asiatica (CA03 and CA23) were subjected to gamma radiation to examine the response of these accessions in terms of survival rate, flavonoid contents, leaf gas exchange and leaf mass. Radiation Sensitivity Tests revealed that based on the survival rate, the LD50 (gamma doses that killed 50% of the plantlets) of the plantlets were achieved at 60 Gy for CA03 and 40 Gy for CA23. The nodal segments were irradiated with gamma rays at does of 30 and 40 Gy for Centella asiatica accession ‘CA03’ and 20 and 30 Gy for accession ‘CA23. The nodal segment response to the radiation was evaluated by recording the flavonoid content, leaf gas exchange and leaf biomass. The experiment was designed as RCBD with five replications. Results demonstrated that the irradiated plantlets exhibited greater total flavonoid contents (in eight weeks) significantly than the control where the control also exhibited the highest total flavonoid contents in the sixth week of growth; 2.64 ± 0.02 mg/g DW in CA03 and 8.94 ± 0.04 mg/g DW in CA23. The total flavonoid content was found to be highest after eight weeks of growth, and this, accordingly, stands as the best time for leaf harvest. Biochemical differentiation based on total flavonoid content revealed that irradiated plantlets in CA23 at 20 and 30 Gy after eight weeks contained the highest total flavonoid concentrations (16.827 ± 0.02; 16.837 ± 0.008 mg/g DW, respectively) whereas in CA03 exposed to 30 and 40 Gy was found to have the lowest total flavonid content (5.83 ± 0.11; 5.75 ± 0.03 mg/g DW). Based on the results gathered in this study, significant differences were found between irradiated accessions and control ones in relation to the leaf gas. The highest PN and gs were detected in CA23 as control followed by CA23 irradiated to 20Gy (CA23G20) and CA23G30 and the lowest PN and gs were observed in CA03 irradiated to 40Gy (CA03G40). Moreover, there were no significant differences in terms of PN and gs among the irradiated plants in each accession. The WUE of both irradiated accessions of Centella asiatica were reduced as compared with the control plants (p < 0.01) while Ci and E were enhanced. There were no significant differences in the gas exchange parameters among radiated plants in each accession. Moreover, malondialdehyde (MDA) of accessions after gamma treatments were significantly higher than the control, however, flavonoids which were higher concentration in irradiated plants can scavenge surplus free radicals. Therefore, the findings of this study have proven an efficient method of in vitro mutagenesis through gamma radiation based on the pharmaceutical demand to create economically superior mutants of C. asiatica. In other words, the results of this study suggest that gamma irradiation on C. asiatica can produce mutants of agricultural and economical importance. Full article
Open AccessArticle Enantioselective Evans-Tishchenko Reduction of b-Hydroxyketone Catalyzed by Lithium Binaphtholate
Molecules 2011, 16(6), 5008-5019; doi:10.3390/molecules16065008
Received: 1 June 2011 / Revised: 10 June 2011 / Accepted: 15 June 2011 / Published: 17 June 2011
Cited by 4 | PDF Full-text (211 KB)
Abstract Lithium diphenylbinaphtholate catalyzed the enantioselective Evans-Tishchenko reduction of achiral b-hydroxyketones to afford monoacyl-protected 1,3-diols with high stereoselectivities. In the reaction of racemic b-hydroxyketones, kinetic optical resolution occurred in a highly stereoselective manner. Full article
(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)
Open AccessArticle Ru/Me-BIPAM-Catalyzed Asymmetric Addition of Arylboronic Acids to Aliphatic Aldehydes and α-Ketoesters
Molecules 2011, 16(6), 5020-5034; doi:10.3390/molecules16065020
Received: 31 May 2011 / Revised: 13 June 2011 / Accepted: 15 June 2011 / Published: 17 June 2011
Cited by 34 | PDF Full-text (266 KB)
Abstract A ruthenium-catalyzed asymmetric arylation of aliphatic aldehydes and α-ketoesters with arylboronic acids has been developed, giving chiral alkyl(aryl)methanols and α-hydroxy esters in good yields. The use of a chiral bidentate phosphoramidite ligand (Me-BIPAM) achieved excellent enantioselectivities. Full article
(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)
Figures

Open AccessArticle Synthetic Dye - Inorganic Salt Hybrid Colorants for Application in Thermoplastics
Molecules 2011, 16(6), 5035-5053; doi:10.3390/molecules16065035
Received: 22 February 2011 / Revised: 13 June 2011 / Accepted: 16 June 2011 / Published: 17 June 2011
Cited by 2 | PDF Full-text (2708 KB)
Abstract
Common synthetic dyes, e.g., Weak Acid Pink Red B (APRB, C.I. 18073), Mordant Blue 9 (MB, C.I.14855) and Acid Brilliant Blue 6B (ABB6B, C.I. 42660), can be removed from water by in situ hybridization with CaCO3, BaSO4 and Ca [...] Read more.
Common synthetic dyes, e.g., Weak Acid Pink Red B (APRB, C.I. 18073), Mordant Blue 9 (MB, C.I.14855) and Acid Brilliant Blue 6B (ABB6B, C.I. 42660), can be removed from water by in situ hybridization with CaCO3, BaSO4 and Ca3(PO4)2 and the resulting hybrids thus prepared used as plastic colorants. All the hybrids can be processed into polypropylene (PP) at 200 °C with good color intensity, color brightness and homogeneous dispersion. The BaSO4-MB hybrid exhibits better migration resistance to acid and alkali, and stronger covering power than the BaSO4-MB mixture. The thermal stability and UV resistance of the Ca3(PO4)2-ABB6B hybrid are better than those of the Ca3(PO4)2-ABB6B mixture. The crystallinity of PP is enhanced by incorporation of these hybrids and the use of these hybrids as colorants in PP instead of the dyes alone is determined to be feasible. Full article
Open AccessArticle Cholesterol-Lowering Activity of the Major Polyphenols in Grape Seed
Molecules 2011, 16(6), 5054-5061; doi:10.3390/molecules16065054
Received: 8 April 2011 / Revised: 13 June 2011 / Accepted: 16 June 2011 / Published: 17 June 2011
Cited by 38 | PDF Full-text (262 KB)
Abstract
The major polyphenols in grape seed have been shown to have beneficial health effects in the prevention of dyslipidemia and cardiovascular diseases. In this present study, we investigated the cholesterol-lowering activity of three major polyphenolic compounds found in grape seed. The results [...] Read more.
The major polyphenols in grape seed have been shown to have beneficial health effects in the prevention of dyslipidemia and cardiovascular diseases. In this present study, we investigated the cholesterol-lowering activity of three major polyphenolic compounds found in grape seed. The results showed that gallic acid, catechin, and epicatechin significantly inhibited pancreatic cholesterol esterase in a concentration-dependent manner. Moreover, they bound to taurocholic acid, taurodeoxycholic acid, and glycodeoxycholic acid at levels ranging from 38.6% to 28.2%. At the concentration of 0.2 mg/mL, gallic acid, catechin, and epicatechin reduced the formation of cholesterol micelles 27.26 ± 2.17%, 11.88 ± 0.75%, and 19.49 ± 3.71%, respectively. These findings clearly demonstrate that three major polyphenolic compounds present in a particular grape seed have cholesterol-lowering activity by inhibiting pancreatic cholesterol esterase, binding of bile acids, and reducing solubility of cholesterol in micelles which may result in delayed cholesterol absorption. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Two-Carbon Homologation of Aldehydes and Ketones to α,β-Unsaturated Aldehydes
Molecules 2011, 16(6), 5062-5078; doi:10.3390/molecules16065062
Received: 28 April 2011 / Revised: 31 May 2011 / Accepted: 13 June 2011 / Published: 17 June 2011
Cited by 4 | PDF Full-text (206 KB)
Abstract
Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle [...] Read more.
Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two-step process worked with a variety of aldehydes and ketones. Overall isolated yields of unsaturated aldehyde products ranged from 71% to 86% after the condensation and deprotection steps. Full article
(This article belongs to the Special Issue Protecting Group in Organic Synthesis)
Open AccessArticle Nematocidal Flavone-C-Glycosides against the Root-Knot Nematode (Meloidogyne incognita) from Arisaema erubescens Tubers
Molecules 2011, 16(6), 5079-5086; doi:10.3390/molecules16065079
Received: 20 May 2011 / Revised: 7 June 2011 / Accepted: 15 June 2011 / Published: 20 June 2011
Cited by 14 | PDF Full-text (252 KB)
Abstract
A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall.) Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita). From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided [...] Read more.
A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall.) Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita). From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided fractionation. The compounds were identified as schaftoside and isoschaftoside on the basis of their phytochemical and spectral data. Schaftoside and isoschaftoside possessed strong nematicidal activity against M. incognita (LC50 = 114.66 μg/mL and 323.09 μg/mL, respectively) while the crude extract of A. erubescens exhibited nematicidal activity against the root-knot nematode with a LC50 value of 258.11 μg/mL. Full article
Open AccessArticle Crystallization and Characterization of an Inflammatory Lectin Purified from the Seeds of Dioclea wilsonii
Molecules 2011, 16(6), 5087-5103; doi:10.3390/molecules16065087
Received: 14 April 2011 / Revised: 7 June 2011 / Accepted: 17 June 2011 / Published: 20 June 2011
Cited by 12 | PDF Full-text (699 KB)
Abstract
DwL, a lectin extracted from the seeds of Dioclea wilsonii, is a metalloprotein with strong agglutinating activity against rabbit and ABO erythrocytes, inhibited by glucose and mannose. DwL was purified by affinity chromatography on a Sephadex G-50 column and ion exchange [...] Read more.
DwL, a lectin extracted from the seeds of Dioclea wilsonii, is a metalloprotein with strong agglutinating activity against rabbit and ABO erythrocytes, inhibited by glucose and mannose. DwL was purified by affinity chromatography on a Sephadex G-50 column and ion exchange chromatography on a HiTrap SP XL column. SDS-PAGE revealed three electrophoretic bands corresponding to the α (25,634 ± 2 Da), β (12,873 ± 2 Da) and γ (12,779 ± 2 Da) chains. Protein sequencing was done by Tandem Mass Spectrometry. The primary sequence featured 237 amino acids and was highly homologous to other reported Diocleinae lectins. A complete X-ray dataset was collected at 2.0 Å for X-Man-complexed DWL crystals produced by the vapor diffusion method. The crystals were orthorhombic and belonged to the space group I222, with the unit-cell parameters a = 59.6, b = 67.9 and c = 109.0 Å. DWL differed in potency from other ConA-like lectins and was found to induce neutrophil migration in rats, making it particularly useful in structural/functional studies of this class of proteins. Full article
Open AccessArticle Characteristic Aroma Compounds from Different Pineapple Parts
Molecules 2011, 16(6), 5104-5112; doi:10.3390/molecules16065104
Received: 2 April 2011 / Revised: 10 June 2011 / Accepted: 15 June 2011 / Published: 20 June 2011
Cited by 16 | PDF Full-text (175 KB)
Abstract
Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp [...] Read more.
Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp were higher than those found in core. In pulp, the characteristic aroma compounds were ethyl 2-methylbutanoate, ethyl hexanoate, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), decanal, ethyl 3-(methylthio)propionate, ethyl butanoate, and ethyl (E)-3-hexenoate; while in core the main compounds were ethyl 2-methylbutanoate, ethyl hexanoate and DMHF. The highest odor units were found to correspond to ethyl 2-methylbutanoate, followed by ethyl hexanoate and DMHF. The odor units found for pulp were higher than those for core. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Methoxymethyl (MOM) Group Nitrogen Protection of Pyrimidines Bearing C-6 Acyclic Side-Chains
Molecules 2011, 16(6), 5113-5129; doi:10.3390/molecules16065113
Received: 26 May 2011 / Revised: 15 June 2011 / Accepted: 16 June 2011 / Published: 20 June 2011
Cited by 5 | PDF Full-text (221 KB)
Abstract
Novel N-methoxymethylated (MOM) pyrimidine (4-13) and pyrimidine-2,4-diones (15-17) nucleoside mimetics in which an isobutyl side-chain is attached at the C-6 position of the pyrimidine moiety were synthesized. Synthetic methods via O-persilylated or [...] Read more.
Novel N-methoxymethylated (MOM) pyrimidine (4-13) and pyrimidine-2,4-diones (15-17) nucleoside mimetics in which an isobutyl side-chain is attached at the C-6 position of the pyrimidine moiety were synthesized. Synthetic methods via O-persilylated or N-anionic uracil derivatives have been evaluated for the synthesis of N-1- and/or N-3-MOM pyrimidine derivatives with C-6 acyclic side-chains. A synthetic approach using an activated N-anionic pyrimidine derivative afforded the desired N,N-1,3-diMOM and N-1-MOM pyrimidines 4 and 5 in good yield. Introduction of fluorine into the side-chain was performed with DAST as the fluorinating reagent to give a N,N-1,3-diMOM pyrimidine 13 with a 1-fluoro-3-hydroxyisobutyl moiety at C-6. Conformational study of the monotritylated N-1-MOM pyrimidine 12 by the use of the NOE experiments revealed the predominant conformation of the compound to be one where the hydroxymethyl group in the C-6 side-chain is close to the N-1-MOM moiety, while the OMTr is in proximity to the CH3-5 group. Contrary to this no NOE enhancements between the N-1-MOM group and hydroxymethyl or fluoromethyl protons in 13 were observed, which suggested a nonrestricted rotation along the C-6 side-chain. Fluorinated N,N-1,3-diMOM pyrimidine 13 emerged as a model compound for development of tracer molecules for non-invasive imaging of gene expression using positron emission tomography (PET). Full article
Open AccessArticle Synthesis and Cytotoxic Evaluation of Novel N-Methyl-4-phenoxypicolinamide Derivatives
Molecules 2011, 16(6), 5130-5141; doi:10.3390/molecules16065130
Received: 1 June 2011 / Revised: 9 June 2011 / Accepted: 10 June 2011 / Published: 20 June 2011
Cited by 2 | PDF Full-text (292 KB)
Abstract
A series of N-methyl-4-phenoxypicolinamide derivatives were synthesized and evaluated in vitro for their cytotoxic activity against A549, H460 and HT29 cell lines. Pharmacological data indicated that some of the target compounds possessed marked antiproliferative activity, superior to that of the reference [...] Read more.
A series of N-methyl-4-phenoxypicolinamide derivatives were synthesized and evaluated in vitro for their cytotoxic activity against A549, H460 and HT29 cell lines. Pharmacological data indicated that some of the target compounds possessed marked antiproliferative activity, superior to that of the reference drug sorafenib. As the most promising compound, 8e exhibited potent cytotoxicity with the IC50 value of 3.6, 1.7 and 3.0 μM against A549, H460 and HT-29 cell lines, respectively. Full article
Open AccessArticle Reactions of Some New Thienothiophene Derivatives
Molecules 2011, 16(6), 5142-5148; doi:10.3390/molecules16065142
Received: 30 May 2011 / Revised: 15 June 2011 / Accepted: 15 June 2011 / Published: 21 June 2011
Cited by 5 | PDF Full-text (170 KB)
Abstract Facile and convenient syntheses of bisdimethylthieno[2,3-b]thiophen-2,5-diyl bis(oxazole-2-amine), bis(1H-imidazol-2-amine), bis((3a)-H-indole),[1,2-a]pyrimidine), bis(1H-imidazo[1,2-b][1,2,4]triazole) and bis(9H-benzo[d]imidazo[1,2-a]imidazole) derivatives incorporating a thieno[2,3-b]thiophene moiety from the versatile and readily accessible 1,1'(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)-bis(2-bromo-ethanone) (1) are described. Full article
(This article belongs to the Special Issue Chemical Libraries)
Open AccessArticle Phytochemical Analysis and In Vitro Antimicrobial and Free-Radical-Scavenging Activities of the Essential Oils from Euryops arabicus and Laggera decurrens
Molecules 2011, 16(6), 5149-5158; doi:10.3390/molecules16065149
Received: 23 May 2011 / Revised: 13 June 2011 / Accepted: 17 June 2011 / Published: 21 June 2011
Cited by 5 | PDF Full-text (118 KB)
Abstract
The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the [...] Read more.
The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the identification of 48 and 44 compounds for both plants, respectively. The essential oil of E. arabicus was rich in oxygenated sesquiterpenes (39.9%). The oil also contained a high content of sesquiterpene hydrocarbons (24.1%). Compounds such as caryophyllene oxide (8.6%), T-cadinol (7.0%), spathulenol (5.2%), (E)-β-caryophyllene (6.0%) and 2-epi-(E)-β-caryophyllene (6.0%) were the main constituents of the oil. Oxygenated monoterpenes also predominated in L. decurrens (46.3%). The thymoquinone-derivative, 3-methoxy-2-methyl-5-(1-methylethyl)-2,5-cyclohexadiene-1,4-dione (28.1%), thymol (5.7%) and eudesma-11-en-4a-ol (7.0%) were the most abundant constituents. Both essential oils showed antimicrobial activity with MIC-values between 0.13–5.25 mg/mL. Furthermore, only the essential oil of L. decurrens exhibited a strong antioxidant activity (91%) at 500 µg/mL. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Inhibitory Activity of Flavonoids against Class I Phosphatidylinositol 3-Kinase Isoforms
Molecules 2011, 16(6), 5159-5167; doi:10.3390/molecules16065159
Received: 3 June 2011 / Revised: 16 June 2011 / Accepted: 17 June 2011 / Published: 21 June 2011
Cited by 12 | PDF Full-text (182 KB)
Abstract
Class I PI3 Kinase (PI3K) phosphorylates phosphatidylinositol 4,5-bisphophate (PIP2) to generate the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) and therefore plays an important role in fundamental cellular responses such as proliferation. There are four isoforms of class I PI3K which are known to [...] Read more.
Class I PI3 Kinase (PI3K) phosphorylates phosphatidylinositol 4,5-bisphophate (PIP2) to generate the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) and therefore plays an important role in fundamental cellular responses such as proliferation. There are four isoforms of class I PI3K which are known to have different functions and relate to various diseases such as cancer and inflammation. Flavonoids are abundant in fruits, vegetables and plant-derived beverages such as tea. So far, various pharmacological effects of flavonoids have been reported. We previously reported that the flavonoid baicalein exhibits potent PI3K-inhibitory activity. Recently we examined the inhibitory activity of eighteen flavonoids against PI3Ka by using an in vitro homogenous time resolved fluorescence (HTRF) kinase assay, and deduced their structure-activity relationships by comparing the activities of the analogues. Our result suggests that the number of hydroxyl groups in the A and B rings might promote the activity, while loss of C2-C3 double bond might reduce the activity. Furthermore, the activity against 4 class I PI3K isoforms of some selected flavonoids was investigated, and the results indicate that the flavonoids seem to exhibit more potent activity on PI3Ka and d isoforms compared with that on PI3Kb and g isoforms. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Identification of N6,N6-Dimethyladenosine in Transfer RNA from Mycobacterium bovis Bacille Calmette-Guérin
Molecules 2011, 16(6), 5168-5181; doi:10.3390/molecules16065168
Received: 4 May 2011 / Revised: 3 June 2011 / Accepted: 10 June 2011 / Published: 21 June 2011
Cited by 5 | PDF Full-text (408 KB) | Supplementary Files
Abstract
There are more than 100 different ribonucleoside structures incorporated as post-transcriptional modifications, mainly in tRNA and rRNA of both prokaryotes and eukaryotes, and emerging evidence suggests that these modifications function as a system in the translational control of cellular responses. However, our [...] Read more.
There are more than 100 different ribonucleoside structures incorporated as post-transcriptional modifications, mainly in tRNA and rRNA of both prokaryotes and eukaryotes, and emerging evidence suggests that these modifications function as a system in the translational control of cellular responses. However, our understanding of this system is hampered by the paucity of information about the complete set of RNA modifications present in individual organisms. To this end, we have employed a chromatography-coupled mass spectrometric approach to define the spectrum of modified ribonucleosides in microbial species, starting with Mycobacterium bovis BCG. This approach revealed a variety of ribonucleoside candidates in tRNA from BCG, of which 12 were definitively identified based on comparisons to synthetic standards and 5 were tentatively identified by exact mass comparisons to RNA modification databases. Among the ribonucleosides observed in BCG tRNA was one not previously described in tRNA, which we have now characterized as N6,N6-dimethyladenosine. Full article
(This article belongs to the Special Issue Nucleoside Analogues)
Open AccessArticle Synthesis of Some Novel Pyrazolo[1,5-a]pyrimidine Derivatives and Their Application as Disperse Dyes
Molecules 2011, 16(6), 5182-5193; doi:10.3390/molecules16065182
Received: 1 June 2011 / Revised: 9 June 2011 / Accepted: 15 June 2011 / Published: 22 June 2011
Cited by 10 | PDF Full-text (223 KB)
Abstract
A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hydrazone product with hydrazine hydrate. The pyrazolohydrazone 6 is then treated with either 2,4-pentandione [...] Read more.
A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hydrazone product with hydrazine hydrate. The pyrazolohydrazone 6 is then treated with either 2,4-pentandione and enaminonitrile or aryl-substituted enaminoketones to give the target pyrazolo[1,5-a]pyrimidine dyes 7 and 15a-d. Structural assignments to the dyes were made using NMR spectroscopic methods. A new high temperature method, using microwave heating, was employed to apply these dyes to polyester fibers. Most of the dyed fabrics tested displayed moderate light fastness and excellent washing fastness properties. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Microwave-Assisted Solution-Phase Synthesis and DART-Mass Spectrometric Monitoring of a Combinatorial Library of Indolin-2,3-dione Schiff Bases with Potential Antimycobacterial Activity
Molecules 2011, 16(6), 5194-5206; doi:10.3390/molecules16065194
Received: 9 May 2011 / Revised: 12 June 2011 / Accepted: 21 June 2011 / Published: 22 June 2011
Cited by 7 | PDF Full-text (307 KB)
Abstract
A combinatorial library composed of eleven hydrazides A-K and eleven indolin-1,2-dione derivatives 1-11 has been designed to formally generate sublibraries of 22 mixtures, M1-M22 comprising of 121 Schiff bases, A-K(1-11). The designed library has been synthesized [...] Read more.
A combinatorial library composed of eleven hydrazides A-K and eleven indolin-1,2-dione derivatives 1-11 has been designed to formally generate sublibraries of 22 mixtures, M1-M22 comprising of 121 Schiff bases, A-K(1-11). The designed library has been synthesized by the solution-phase method and microwave-assisted synthetic techniques. The formation of individual compounds of each mixture was confirmed by Direct Analysis in Real Time (DART) as ionization technique connected to an Ion Trap as a mass detector. The synthesized mixtures were evaluated for their antimycobacterial activity against four Mycobacterium strains; M. intercellulari, M. xenopi, M. cheleneoi and M. smegmatis. Variable antimycobacterial activity was revealed with the investigated mixtures and maximum activity was shown by M8, M10, M11, and M15 with MIC values of 1.5, 3.1, 6.2 and 0.09 μg/mL, respectively. Application of the indexed method of analysis on these active mixtures revealed that compounds D8, D10 and D11 may contribute to the activity of the tested mixtures. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Synthesis and Characterization of (Z)-5-Arylmethylidene-rhodanines with Photosynthesis-Inhibiting Properties
Molecules 2011, 16(6), 5207-5227; doi:10.3390/molecules16065207
Received: 16 May 2011 / Revised: 15 June 2011 / Accepted: 21 June 2011 / Published: 22 June 2011
Cited by 7 | PDF Full-text (219 KB)
Abstract
A series of rhodanine derivatives was prepared. The synthetic approach, analytical and spectroscopic data of all synthesized compounds are presented. Lipophilicity of all the discussed rhodanine derivatives was analyzed using the RP-HPLC method. The compounds were tested for their ability to inhibit [...] Read more.
A series of rhodanine derivatives was prepared. The synthetic approach, analytical and spectroscopic data of all synthesized compounds are presented. Lipophilicity of all the discussed rhodanine derivatives was analyzed using the RP-HPLC method. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts and reduce chlorophyll content in freshwater alga Chlorella vulgaris. Structure-activity relationships between the chemical structure, physical properties and biological activities of the evaluated compounds are discussed. For majority of the tested compounds the lipophilicity of the compound and not electronic properties of the R1 substituent were decisive for PET-inhibiting activity. The most potent PET inhibitor was (5Z)-5-(4-bromobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC50 = 3.0 μmol/L) and the highest antialgal activity was exhibited by (5Z)-5-(4-chlorobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC50 = 1.3 μmol/L). Full article
(This article belongs to the Special Issue ECSOC-11)
Open AccessArticle Maleimido-Functionalized NOTA Derivatives as Bifunctional Chelators for Site-Specific Radiolabeling
Molecules 2011, 16(6), 5228-5240; doi:10.3390/molecules16065228
Received: 24 May 2011 / Revised: 10 June 2011 / Accepted: 17 June 2011 / Published: 22 June 2011
Cited by 4 | PDF Full-text (187 KB)
Abstract
Two basic and simple synthetic routes for mono- and bis-maleimide bearing 1,4,7-triazacyclononane-N,N’,N’’-triacetic acid (NOTA) chelators as new bifunctional chelators are described. The syntheses are characterized by their simplicity and short reaction times, as well as practical [...] Read more.
Two basic and simple synthetic routes for mono- and bis-maleimide bearing 1,4,7-triazacyclononane-N,N’,N’’-triacetic acid (NOTA) chelators as new bifunctional chelators are described. The syntheses are characterized by their simplicity and short reaction times, as well as practical purification methods and acceptable to very good chemical yields. The usefulness of these two synthetic pathways is demonstrated by the preparation of a set of mono- and bis-maleimide functionalized NOTA derivatives. In conclusion, these two methods can easily be expanded to the syntheses of further tailored maleimide-NOTA chelators for diverse applications. Full article
(This article belongs to the Section Organic Synthesis)
Figures

Open AccessArticle Acute Oral Toxicity of Methanolic Seed Extract of Cassia fistula in Mice
Molecules 2011, 16(6), 5268-5282; doi:10.3390/molecules16065268
Received: 23 May 2011 / Accepted: 22 June 2011 / Published: 23 June 2011
Cited by 22 | PDF Full-text (653 KB)
Abstract
Background and objective: Cassia fistula is widely used in traditional medicine to treat various types of ailments. The evaluation of toxic properties of C. fistula is crucial when considering public health protection because exposure to plant extracts can result in undesirable effects [...] Read more.
Background and objective: Cassia fistula is widely used in traditional medicine to treat various types of ailments. The evaluation of toxic properties of C. fistula is crucial when considering public health protection because exposure to plant extracts can result in undesirable effects on consumers. Hence, in this study the acute oral toxicity of C. fistula seeds extract was investigated in mice. Results: Oral administration of crude extract at the highest dose of 5000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that C. fistula in nontoxic. Throughout 14 days of the treatment no changes in behavioural pattern, clinical sign and body weight of mice in both control and treatment groups. Also there were no any significant elevations observed in the biochemical analysis of the blood serum. Further, histopathological examination revealed normal architecture and no significant adverse effects observed on the kidney, heart, liver, lung and spleen. Conclusions: Overall, the results suggest that, the oral administration of C. fistula methanolic seeds extract did not produce any significant toxic effect in mice. Hence, the extract can be utilized for pharmaceutical formulations. Full article
(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)
Open AccessArticle Enantio and Diastereoselective Addition of Phenylacetylene to Racemic α-chloroketones
Molecules 2011, 16(6), 5298-5314; doi:10.3390/molecules16065298
Received: 26 May 2011 / Revised: 17 June 2011 / Accepted: 22 June 2011 / Published: 23 June 2011
Cited by 4 | PDF Full-text (235 KB)
Abstract
In this report, we have presented the first diastereoselective addition of phenylacetylene to chiral racemic chloroketones. The addition is controlled by the reactivity of the chloroketones that allowed the stereoselective reaction to be performed at –20 °C. Chiral racemic chloroketones are used [...] Read more.
In this report, we have presented the first diastereoselective addition of phenylacetylene to chiral racemic chloroketones. The addition is controlled by the reactivity of the chloroketones that allowed the stereoselective reaction to be performed at –20 °C. Chiral racemic chloroketones are used in the reaction. By carefully controlling the temperature and the reaction time we were able to isolate the corresponding products in moderate yields and with good, simple and predictable facial stereoselection. Our reaction is a rare example of the use of chiral ketones in an enantioselective alkynylation reaction and opens new perspectives for the formation of chiral quaternary stereocenters. Full article
(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)
Figures

Review

Jump to: Research

Open AccessReview Targeting Oncogenic Protein-Protein Interactions by Diversity Oriented Synthesis and Combinatorial Chemistry Approaches
Molecules 2011, 16(6), 4408-4427; doi:10.3390/molecules16064408
Received: 10 March 2011 / Revised: 4 May 2011 / Accepted: 25 May 2011 / Published: 27 May 2011
Cited by 13 | PDF Full-text (501 KB)
Abstract
We are currently witnessing a decline in the development of efficient new anticancer drugs, despite the salient efforts made on all fronts of cancer drug discovery. This trend presumably relates to the substantial heterogeneity and the inherent biological complexity of cancer, which [...] Read more.
We are currently witnessing a decline in the development of efficient new anticancer drugs, despite the salient efforts made on all fronts of cancer drug discovery. This trend presumably relates to the substantial heterogeneity and the inherent biological complexity of cancer, which hinder drug development success. Protein-protein interactions (PPIs) are key players in numerous cellular processes and aberrant interruption of this complex network provides a basis for various disease states, including cancer. Thus, it is now believed that cancer drug discovery, in addition to the design of single-targeted bioactive compounds, should also incorporate diversity-oriented synthesis (DOS) and other combinatorial strategies in order to exploit the ability of multi-functional scaffolds to modulate multiple protein-protein interactions (biological hubs). Throughout the review, we highlight the chemistry driven approaches to access diversity space for the discovery of small molecules that disrupt oncogenic PPIs, namely the p53-Mdm2, Bcl-2/Bcl-xL-BH3, Myc-Max, and p53-Mdmx/Mdm2 interactions. Full article
(This article belongs to the Special Issue Diversity Oriented Synthesis)
Figures

Open AccessReview Locked and Unlocked Nucleosides in Functional Nucleic Acids
Molecules 2011, 16(6), 4511-4526; doi:10.3390/molecules16064511
Received: 3 May 2011 / Revised: 19 May 2011 / Accepted: 25 May 2011 / Published: 27 May 2011
Cited by 23 | PDF Full-text (188 KB)
Abstract
Nucleic acids are able to adopt a plethora of structures, many of which are of interest in therapeutics, bio- or nanotechnology. However, structural and biochemical stability is a major concern which has been addressed by incorporating a range of modifications and nucleoside [...] Read more.
Nucleic acids are able to adopt a plethora of structures, many of which are of interest in therapeutics, bio- or nanotechnology. However, structural and biochemical stability is a major concern which has been addressed by incorporating a range of modifications and nucleoside derivatives. This review summarizes the use of locked nucleic acid (LNA) and un-locked nucleic acid (UNA) monomers in functional nucleic acids such as aptamers, ribozymes, and DNAzymes. Full article
(This article belongs to the Special Issue Nucleoside Analogues)
Open AccessReview Curcumin: An Anti-Inflammatory Molecule from a Curry Spice on the Path to Cancer Treatment
Molecules 2011, 16(6), 4567-4598; doi:10.3390/molecules16064567
Received: 9 May 2011 / Revised: 25 May 2011 / Accepted: 26 May 2011 / Published: 3 June 2011
Cited by 163 | PDF Full-text (356 KB)
Abstract
Oxidative damage and inflammation have been pointed out in preclinical studies as the root cause of cancer and other chronic diseases such as diabetes, hypertension, Alzheimer’s disease, etc. Epidemiological and clinical studies have suggested that cancer could be prevented or significantly [...] Read more.
Oxidative damage and inflammation have been pointed out in preclinical studies as the root cause of cancer and other chronic diseases such as diabetes, hypertension, Alzheimer’s disease, etc. Epidemiological and clinical studies have suggested that cancer could be prevented or significantly reduced by treatment with anti-oxidant and anti-inflammatory drugs, therefore, curcumin, a principal component of turmeric (a curry spice) showing strong anti-oxidant and anti-inflammatory activities, might be a potential candidate for the prevention and/or treatment of cancer and other chronic diseases. However, curcumin, a highly pleiotropic molecule with an excellent safety profile targeting multiple diseases with strong evidence on the molecular level, could not achieve its optimum therapeutic outcome in past clinical trials, largely due to its low solubility and poor bioavailability. Curcumin can be developed as a therapeutic drug through improvement in formulation properties or delivery systems, enabling its enhanced absorption and cellular uptake. This review mainly focuses on the anti-inflammatory potential of curcumin and recent developments in dosage form and nanoparticulate delivery systems with the possibilities of therapeutic application of curcumin for the prevention and/or treatment of cancer. Full article
Open AccessReview Synthetic Routes and Biological Evaluation of Largazole and Its Analogues as Potent Histone Deacetylase Inhibitors
Molecules 2011, 16(6), 4681-4694; doi:10.3390/molecules16064681
Received: 25 April 2011 / Revised: 13 May 2011 / Accepted: 18 May 2011 / Published: 7 June 2011
Cited by 11 | PDF Full-text (420 KB)
Abstract
Natural products with interesting biological properties and structural diversity have often served as valuable lead drug candidates for the treatment of various human diseases. Largazole, isolated from the marine cyanobacterium Symploca sp. has exhibited potent inhibitory activity against many cancer cell lines. [...] Read more.
Natural products with interesting biological properties and structural diversity have often served as valuable lead drug candidates for the treatment of various human diseases. Largazole, isolated from the marine cyanobacterium Symploca sp. has exhibited potent inhibitory activity against many cancer cell lines. Besides, it shows remarkable selectivity between transformed and nontransformed cells, which is the main disadvantage of other antitumor natural products such as paclitaxel and actinomycin D. Due to its potential as a potent and selective anticancer drug candidate, a great deal of attention has been focused on largazole and its analogues. It is the aim of this review to highlight synthetic aspects of largazole and its analogues as well as their preliminary structure–activity relationship studies. Full article
Open AccessReview Recent Advances in the Studies on Luotonins
Molecules 2011, 16(6), 4861-4883; doi:10.3390/molecules16064861
Received: 12 April 2011 / Revised: 8 June 2011 / Accepted: 10 June 2011 / Published: 14 June 2011
Cited by 22 | PDF Full-text (812 KB)
Abstract
Luotonins are alkaloids from the aerial parts of Peganum nigellastrum Bunge. that display three major skeleton types. Luotonins A, B, and E are pyrroloquinazolino-quinoline alkaloids, luotonins C and D are canthin-6-one alkaloids, and luotonin F is a 4(3H)-quinazolinone alkaloid. All [...] Read more.
Luotonins are alkaloids from the aerial parts of Peganum nigellastrum Bunge. that display three major skeleton types. Luotonins A, B, and E are pyrroloquinazolino-quinoline alkaloids, luotonins C and D are canthin-6-one alkaloids, and luotonin F is a 4(3H)-quinazolinone alkaloid. All six luotonins have shown promising cytotoxicities towards selected human cancer cell lines, especially against leukemia P-388 cells. Luotonin A is the most active one, with its activity stemming from topoisomerase I-dependent DNA-cleavage. Such intriguing biological activities and unique structures have led not only to the development of synthetic methods for the efficient synthesis of these compounds, but also to interest in structural modifications for improving the biological properties. Recent progress in the study of luotonins is covered. Full article
Open AccessReview Recent Advances in the Synthesis of N-Containing Heteroaromatics via Heterogeneously Transition Metal Catalysed Cross-Coupling Reactions
Molecules 2011, 16(6), 5241-5267; doi:10.3390/molecules16065241
Received: 31 May 2011 / Revised: 20 June 2011 / Accepted: 21 June 2011 / Published: 23 June 2011
Cited by 20 | PDF Full-text (845 KB)
Abstract
N-containing heteroaromatics are important substructures found in numerous natural or synthetic alkaloids. The diversity of the structures encountered, as well as their biological and pharmaceutical relevance, have motivated research aimed at the development of new economical, efficient and selective synthetic strategies to [...] Read more.
N-containing heteroaromatics are important substructures found in numerous natural or synthetic alkaloids. The diversity of the structures encountered, as well as their biological and pharmaceutical relevance, have motivated research aimed at the development of new economical, efficient and selective synthetic strategies to access these compounds. Over more than 100 years of research, this hot topic has resulted in numerous so-called “classical synthetic methods” that have really contributed to this important area. However, when the selective synthesis of highly functional heteroaromatics like indoles, quinolones, indoxyls, etc. is considered these methods remain limited. Recently transition metal-catalysed (TM-catalysed) procedures for the synthesis of such compounds and further transformations, have been developed providing increased tolerance toward functional groups and leading generally to higher reaction yields. Many of these methods have proven to be the most powerful and are currently applied in target- or diversity-oriented syntheses. This review article aims at reporting the recent developments devoted to this important area, focusing on the use of heterogeneous catalysed procedures that include either the formation of the heterocyclic ring towards the nuclei or their transformations to highly substituted compounds. Full article
(This article belongs to the Special Issue Cross-Coupling Reactions in Organic Synthesis)
Figures

Open AccessReview The Main Anticancer Bullets of the Chinese Medicinal Herb, Thunder God Vine
Molecules 2011, 16(6), 5283-5297; doi:10.3390/molecules16065283
Received: 18 April 2011 / Revised: 17 June 2011 / Accepted: 20 June 2011 / Published: 23 June 2011
Cited by 47 | PDF Full-text (341 KB)
Abstract
The thunder god vine or Tripterygium wilfordii Hook. F. is a representative Chinese medicinal herb which has been used widely and successfully for centuries in treating inflammatory diseases. More than 100 components have been isolated from this plant, and most of them [...] Read more.
The thunder god vine or Tripterygium wilfordii Hook. F. is a representative Chinese medicinal herb which has been used widely and successfully for centuries in treating inflammatory diseases. More than 100 components have been isolated from this plant, and most of them have potent therapeutic efficacy for a variety of autoimmune and inflammatory diseases. In the past four decades, the anticancer activities of the extracts from this medicinal herb have attracted intensive attention by researchers worldwide. The diterpenoid epoxide triptolide and the quinone triterpene celastrol are two important bioactive ingredients that show a divergent therapeutic profile and can perturb multiple signal pathways. Both compounds promise to turn traditional medicines into modern drugs. In this review, we will mainly address the anticancer activities and mechanisms of action of these two agents and briefly describe some other antitumor components of the thunder god vine. Full article
(This article belongs to the collection Bioactive Compounds)

Journal Contact

MDPI AG
Molecules Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
molecules@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Molecules
Back to Top