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Molecules, Volume 21, Issue 6 (June 2016)

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Cover Story (view full-size image) Natural products have always been exploited to promote health and have served as a valuable source [...] Read more.
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Open AccessArticle Uprolides N, O and P from the Panamanian Octocoral Eunicea succinea
Molecules 2016, 21(6), 819; https://doi.org/10.3390/molecules21060819
Received: 11 May 2016 / Revised: 17 June 2016 / Accepted: 18 June 2016 / Published: 22 June 2016
Cited by 1 | PDF Full-text (1507 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Three new diterpenes, uprolide N (1), uprolide O (2), uprolide P (3) and a known one, dolabellane (4), were isolated from the CH2Cl2-MeOH extract of the gorgonian octocoral Eunicea succinea,
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Three new diterpenes, uprolide N (1), uprolide O (2), uprolide P (3) and a known one, dolabellane (4), were isolated from the CH2Cl2-MeOH extract of the gorgonian octocoral Eunicea succinea, collected from Bocas del Toro, on the Caribbean coast of Panama. Their structures were determined using spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HRMS) together with molecular modeling studies. Compounds 13 displayed anti-inflammatory properties by inhibiting production of Tumor Necrosis Factor (TNF) and Interleukin (IL)-6 induced by lipopolysaccharide (LPS) in murine macrophages. Full article
(This article belongs to the Special Issue Diterpene and Its Significance in Natural Medicine)
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Open AccessArticle Anti-Inflammatory Effects of Melandrii Herba Ethanol Extract via Inhibition of NF-κB and MAPK Signaling Pathways and Induction of HO-1 in RAW 264.7 Cells and Mouse Primary Macrophages
Molecules 2016, 21(6), 818; https://doi.org/10.3390/molecules21060818
Received: 20 April 2016 / Revised: 15 June 2016 / Accepted: 20 June 2016 / Published: 22 June 2016
Cited by 4 | PDF Full-text (2067 KB) | HTML Full-text | XML Full-text
Abstract
Melandrii Herba (MH) is a traditional Asian medicinal herb used to treat breast cancer, anuria, and diseases of lactation. However, its biological properties and molecular mechanisms have not been fully elucidated. The purpose of this study was to investigate the anti-inflammatory activity and
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Melandrii Herba (MH) is a traditional Asian medicinal herb used to treat breast cancer, anuria, and diseases of lactation. However, its biological properties and molecular mechanisms have not been fully elucidated. The purpose of this study was to investigate the anti-inflammatory activity and underlying molecular mechanism of MH ethanol extract (MHE) on the lipopolysaccharide (LPS)-mediated inflammatory response in macrophages. MHE cytotoxicity was determined using a cell counting kit (CCK) assay. The effects of MHE on the production of NO, inflammatory cytokines, and related proteins and mRNAs were determined using the Griess test, ELISA, Western blotting, and real-time RT-PCR, respectively. In addition, intracellular signaling pathways, such as NF-κB, MAPK, and HO-1, were analyzed using Western blotting. Our results revealed that MHE treatment significantly inhibited the secretion of NO and inflammatory cytokines, including TNF-α, IL-6, and IL-1β in macrophages, at sub-cytotoxic concentrations. Furthermore, MHE treatment inhibited iNOS expression and induced HO-1 expression. Finally, the transcriptional activities of NF-κB and MAPK activation were significantly suppressed by MHE in LPS-stimulated macrophages. The results indicate that MHE exerts anti-inflammatory effects by suppressing inflammatory mediator production via NF-κB and MAPK signaling pathways inhibition and induction of HO-1 expression in macrophages. Therefore, our results suggest the potential value of MHE as an inflammatory therapeutic agent developed from a natural substance. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis and Evaluation of 99mTc-Labeled Dimeric Folic Acid for FR-Targeting
Molecules 2016, 21(6), 817; https://doi.org/10.3390/molecules21060817
Received: 30 May 2016 / Revised: 17 June 2016 / Accepted: 20 June 2016 / Published: 22 June 2016
Cited by 4 | PDF Full-text (1663 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The folate receptor (FR) is overexpressed in a wide variety of human tumors. In our study, the multimeric concept was used to synthesize a dimeric folate derivative via a click reaction. The novel folate derivative (HYNIC-D1-FA2) was radiolabeled with
[...] Read more.
The folate receptor (FR) is overexpressed in a wide variety of human tumors. In our study, the multimeric concept was used to synthesize a dimeric folate derivative via a click reaction. The novel folate derivative (HYNIC-D1-FA2) was radiolabeled with 99mTc using tricine and trisodium triphenylphosphine-3,3′,3″-trisulfonate (TPPTS) as coligands (99mTc-HYNIC-D1-FA2) and its in vitro physicochemical properties, ex vivo biodistribution and in vivo micro-SPECT/CT imaging as a potential FR targeted agent were evaluated. It is a hydrophilic compound (log P = −2.52 ± 0.13) with high binding affinity (IC50 = 19.06 nM). Biodistribution in KB tumor-bearing mice showed that 99mTc-HYNIC-D1-FA2 had high uptake in FR overexpressed tumor and kidney at all time-points, and both of them could obviously be inhibited when blocking with free FA in the blocking studies. From the in vivo micro-SPECT/CT imaging results, good tumor uptake of 99mTc-HYNIC-D1-FA2 was observed in KB tumor-bearing mice and it could be blocked obviously. Based on the results, this new radiolabeled dimeric FA tracer might be a promising candidate for FR-targeting imaging with high affinity and selectivity. Full article
(This article belongs to the Special Issue Molecular Imaging Probes)
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Open AccessArticle Ultrahigh Pressure Processing Produces Alterations in the Metabolite Profiles of Panax ginseng
Molecules 2016, 21(6), 816; https://doi.org/10.3390/molecules21060816
Received: 25 May 2016 / Revised: 20 June 2016 / Accepted: 20 June 2016 / Published: 22 June 2016
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Abstract
Ultrahigh pressure (UHP) treatments are non-thermal processing methods that have customarily been employed to enhance the quality and productivity of plant consumables. We aimed to evaluate the effects of UHP treatments on ginseng samples (white ginseng: WG; UHP-treated WG: UWG; red ginseng: RG;
[...] Read more.
Ultrahigh pressure (UHP) treatments are non-thermal processing methods that have customarily been employed to enhance the quality and productivity of plant consumables. We aimed to evaluate the effects of UHP treatments on ginseng samples (white ginseng: WG; UHP-treated WG: UWG; red ginseng: RG; UHP-treated RG: URG; ginseng berries: GB; and UHP-treated GB: UGB) using metabolite profiling based on ultrahigh performance liquid chromatography-linear trap quadrupole-ion trap-tandem mass spectrometry (UHPLC-LTQ-IT-MS/MS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Multivariate data analyses revealed a clear demarcation among the GB and UGB samples, and the phenotypic evaluations correlated the highest antioxidant activities and the total phenolic and flavonoid compositions with the UGB samples. Overall, eight amino acids, seven organic acids, seven sugars and sugar derivatives, two fatty acids, three notoginsenosides, three malonylginsenosides, and three ginsenosides, were identified as significantly discriminant metabolites between the GB and UGB samples, with relatively higher proportions in the latter. Ideally, these metabolites can be used as quality biomarkers for the assessment of ginseng products and our results indicate that UHP treatment likely led to an elevation in the proportions of total extractable metabolites in ginseng samples. Full article
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Open AccessArticle Aza-Michael Mono-addition Using Acidic Alumina under Solventless Conditions
Molecules 2016, 21(6), 815; https://doi.org/10.3390/molecules21060815
Received: 20 May 2016 / Revised: 10 June 2016 / Accepted: 16 June 2016 / Published: 22 June 2016
Cited by 7 | PDF Full-text (1284 KB) | HTML Full-text | XML Full-text
Abstract
Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although
[...] Read more.
Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although others such as acrylonitrile, methyl acrylate and acrylamide were also utilized successfully. Bi-functional amines also gave the mono-adducts in good to excellent yields. Such compounds can serve as intermediates for the synthesis of anti-cancer and antibiotic drugs. Full article
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Open AccessArticle Essential Oil Variation from Twenty Two Genotypes of Citrus in Brazil—Chemometric Approach and Repellency Against Diaphorina citri Kuwayama
Molecules 2016, 21(6), 814; https://doi.org/10.3390/molecules21060814
Received: 21 May 2016 / Revised: 15 June 2016 / Accepted: 17 June 2016 / Published: 22 June 2016
Cited by 6 | PDF Full-text (1210 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities
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The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-β-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro
Molecules 2016, 21(6), 813; https://doi.org/10.3390/molecules21060813
Received: 5 May 2016 / Revised: 16 June 2016 / Accepted: 17 June 2016 / Published: 22 June 2016
Cited by 5 | PDF Full-text (8974 KB) | HTML Full-text | XML Full-text
Abstract
Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8), inverted phase contrast microscope and flow cytometry were used
[...] Read more.
Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8), inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS). In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS) in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb. Full article
(This article belongs to the Special Issue Diterpene and Its Significance in Natural Medicine)
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Open AccessArticle The Changes in Color, Soluble Sugars, Organic Acids, Anthocyanins and Aroma Components in “Starkrimson” during the Ripening Period in China
Molecules 2016, 21(6), 812; https://doi.org/10.3390/molecules21060812
Received: 23 May 2016 / Revised: 17 June 2016 / Accepted: 17 June 2016 / Published: 22 June 2016
Cited by 2 | PDF Full-text (1400 KB) | HTML Full-text | XML Full-text
Abstract
“Starkrimson” is a traditional apple cultivar that was developed a long time ago and was widely cultivated in the arid region of the northern Wei River of China. However, little information regarding the quality characteristics of “Starkrimson” fruit has been reported in this
[...] Read more.
“Starkrimson” is a traditional apple cultivar that was developed a long time ago and was widely cultivated in the arid region of the northern Wei River of China. However, little information regarding the quality characteristics of “Starkrimson” fruit has been reported in this area. To elucidate these characteristics, the color, soluble sugars, organic acids, anthocyanins and aroma components were measured during the ripening period through the use of high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The results indicated that the changes in anthocyanin contents took place later than the changes in the Commission International Eclairage (CIE) parameters. Meanwhile, cyanidin 3-galactoside (cy3-gal), fructose, sucrose, glucose and malic acid were the primary organic compounds, and 1-butanol-2-methyl-acetate, 2-hexenal and 1-hexanol were the most abundant aroma components in the skin. Furthermore, rapidly changing soluble sugars and organic acid synchronization took place in the early ripening period, while rapidly changing aroma components occurred later, on the basis of fresh weight. This result suggested that the production of aroma components might be a useful index of apple maturity. Full article
(This article belongs to the Special Issue Structure-Activity Relationship of Natural Products)
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Open AccessArticle Syk and IRAK1 Contribute to Immunopharmacological Activities of Anthraquinone-2-carboxlic Acid
Molecules 2016, 21(6), 809; https://doi.org/10.3390/molecules21060809
Received: 21 May 2016 / Revised: 16 June 2016 / Accepted: 18 June 2016 / Published: 22 June 2016
Cited by 5 | PDF Full-text (4164 KB) | HTML Full-text | XML Full-text
Abstract
Anthraquinone-2-carboxlic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA) was identified as one of the major anthraquinones in Brazilian taheebo. Since there was no report explaining its immunopharmacological actions, in this study, we aimed to investigate the molecular mechanism of AQCA-mediated anti-inflammatory activity using reporter gene assays,
[...] Read more.
Anthraquinone-2-carboxlic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA) was identified as one of the major anthraquinones in Brazilian taheebo. Since there was no report explaining its immunopharmacological actions, in this study, we aimed to investigate the molecular mechanism of AQCA-mediated anti-inflammatory activity using reporter gene assays, kinase assays, immunoblot analyses, and overexpression strategies with lipopolysaccharide (LPS)-treated macrophages. AQCA was found to suppress the release of nitric oxide (NO) and prostaglandin (PG) E2 from LPS-treated peritoneal macrophages without displaying any toxic side effects. Molecular analysis revealed that AQCA was able to inhibit the activation of the nuclear factor (NF)-κB and activator protein (AP)-1 pathways by direct suppression of upstream signaling enzymes including interleukin-1 receptor-associated kinase 1 (IRAK1) and spleen tyrosine kinase (Syk). Therefore, our data strongly suggest that AQCA-mediated suppression of inflammatory responses could be managed by a direct interference of signaling cascades including IRAK and Syk, linked to the activation of NF-κB and AP-1. Full article
(This article belongs to the Section Molecular Diversity)
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Open AccessArticle Novel 5-Substituted 2-(Aylmethylthio)-4-chloro-N-(5-aryl-1,2,4-triazin-3-yl)benzenesulfonamides: Synthesis, Molecular Structure, Anticancer Activity, Apoptosis-Inducing Activity and Metabolic Stability
Molecules 2016, 21(6), 808; https://doi.org/10.3390/molecules21060808
Received: 13 May 2016 / Revised: 8 June 2016 / Accepted: 17 June 2016 / Published: 22 June 2016
Cited by 8 | PDF Full-text (5550 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A series of novel 5-substituted 2-(arylmethylthio)-4-chloro-N-(5-aryl-1,2,4-triazin-3-yl) benzenesulfonamide derivatives 2760 have been synthesized by the reaction of aminoguanidines with an appropriate phenylglyoxal hydrate in glacial acetic acid. A majority of the compounds showed cytotoxic activity toward the human cancer cell
[...] Read more.
A series of novel 5-substituted 2-(arylmethylthio)-4-chloro-N-(5-aryl-1,2,4-triazin-3-yl) benzenesulfonamide derivatives 2760 have been synthesized by the reaction of aminoguanidines with an appropriate phenylglyoxal hydrate in glacial acetic acid. A majority of the compounds showed cytotoxic activity toward the human cancer cell lines HCT-116, HeLa and MCF-7, with IC50 values below 100 μM. It was found that for the analogues 3638 the naphthyl moiety contributed significantly to the anticancer activity. Cytometric analysis of translocation of phosphatidylserine as well as mitochondrial membrane potential and cell cycle revealed that the most active compounds 37 (HCT-116 and HeLa) and 46 (MCF-7) inhibited the proliferation of cells by increasing the number of apoptotic cells. Apoptotic-like, dose dependent changes in morphology of cell lines were also noticed after treatment with 37 and 46. Moreover, triazines 37 and 46 induced caspase activity in the HCT-116, HeLa and MCF-7 cell lines. Selected compounds were tested for metabolic stability in the presence of pooled human liver microsomes and NADPH, both R2 and Ar = 4-CF3-C6H4 moiety in 2-(R2-methylthio)-N-(5-aryl-1,2,4-triazin-3-yl)benzenesulfonamides simultaneously increased metabolic stability. The results pointed to 37 as a hit compound with a good cytotoxicity against HCT-116 (IC50 = 36 μM), HeLa (IC50 = 34 μM) cell lines, apoptosis-inducing activity and moderate metabolic stability. Full article
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Open AccessReview Natural Products to Counteract the Epidemic of Cardiovascular and Metabolic Disorders
Molecules 2016, 21(6), 807; https://doi.org/10.3390/molecules21060807
Received: 1 April 2016 / Revised: 9 June 2016 / Accepted: 13 June 2016 / Published: 22 June 2016
Cited by 32 | PDF Full-text (1020 KB) | HTML Full-text | XML Full-text
Abstract
Natural products have always been exploited to promote health and served as a valuable source for the discovery of new drugs. In this review, the great potential of natural compounds and medicinal plants for the treatment or prevention of cardiovascular and metabolic disorders,
[...] Read more.
Natural products have always been exploited to promote health and served as a valuable source for the discovery of new drugs. In this review, the great potential of natural compounds and medicinal plants for the treatment or prevention of cardiovascular and metabolic disorders, global health problems with rising prevalence, is addressed. Special emphasis is laid on natural products for which efficacy and safety have already been proven and which are in clinical trials, as well as on plants used in traditional medicine. Potential benefits from certain dietary habits and dietary constituents, as well as common molecular targets of natural products, are also briefly discussed. A glimpse at the history of statins and biguanides, two prominent representatives of natural products (or their derivatives) in the fight against metabolic disease, is also included. The present review aims to serve as an “opening” of this special issue of Molecules, presenting key historical developments, recent advances, and future perspectives outlining the potential of natural products for prevention or therapy of cardiovascular and metabolic disease. Full article
(This article belongs to the Special Issue Effects of Natural Products in the Context of Cardiometabolic Disease)
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Open AccessReview Exploiting the Biosynthetic Potential of Type III Polyketide Synthases
Molecules 2016, 21(6), 806; https://doi.org/10.3390/molecules21060806
Received: 20 May 2016 / Revised: 15 June 2016 / Accepted: 17 June 2016 / Published: 22 June 2016
Cited by 8 | PDF Full-text (9927 KB) | HTML Full-text | XML Full-text
Abstract
Polyketides are structurally and functionally diverse secondary metabolites that are biosynthesized by polyketide synthases (PKSs) using acyl-CoA precursors. Recent studies in the engineering and structural characterization of PKSs have facilitated the use of target enzymes as biocatalysts to produce novel functionally optimized polyketides.
[...] Read more.
Polyketides are structurally and functionally diverse secondary metabolites that are biosynthesized by polyketide synthases (PKSs) using acyl-CoA precursors. Recent studies in the engineering and structural characterization of PKSs have facilitated the use of target enzymes as biocatalysts to produce novel functionally optimized polyketides. These compounds may serve as potential drug leads. This review summarizes the insights gained from research on type III PKSs, from the discovery of chalcone synthase in plants to novel PKSs in bacteria and fungi. To date, at least 15 families of type III PKSs have been characterized, highlighting the utility of PKSs in the development of natural product libraries for therapeutic development. Full article
(This article belongs to the Special Issue Polyketides)
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Open AccessArticle Synthesis of Chiral, Enantiopure Allylic Amines by the Julia Olefination of α-Amino Esters
Molecules 2016, 21(6), 805; https://doi.org/10.3390/molecules21060805
Received: 24 May 2016 / Revised: 14 June 2016 / Accepted: 14 June 2016 / Published: 21 June 2016
PDF Full-text (4150 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The four-step conversion of a series of N-Boc-protected l-amino acid methyl esters into enantiopure N-Boc allylamines by a modified Julia olefination is described. Key steps include the reaction of a lithiated phenylalkylsulfone with amino esters, giving chiral β-ketosulfones, and the
[...] Read more.
The four-step conversion of a series of N-Boc-protected l-amino acid methyl esters into enantiopure N-Boc allylamines by a modified Julia olefination is described. Key steps include the reaction of a lithiated phenylalkylsulfone with amino esters, giving chiral β-ketosulfones, and the reductive elimination of related α-acetoxysulfones. The overall transformation takes place under mild conditions, with good yields, and without loss of stereochemical integrity, being in this respect superior to the conventional Julia reaction of α-amino aldehydes. Full article
(This article belongs to the Special Issue Synthesis of Bioactive Compounds from the Chiral Pool)
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Open AccessArticle Flavonoid Glycosides and Their Derivatives from the Herbs of Scorzonera austriaca Wild
Molecules 2016, 21(6), 803; https://doi.org/10.3390/molecules21060803
Received: 22 May 2016 / Revised: 15 June 2016 / Accepted: 17 June 2016 / Published: 21 June 2016
Cited by 2 | PDF Full-text (622 KB) | HTML Full-text | XML Full-text
Abstract
Five flavonoid glycosides and two derivatives were isolated from the herbs of Scorzonera austriaca Wild by silica gel column chromatography and preparative HPLC. Their structures were identified, using chemical and spectroscopic methods, as 5,7,4′-trihydroxyflavone 6-C-(2''-O-β-d-glucopyranosyl β-d
[...] Read more.
Five flavonoid glycosides and two derivatives were isolated from the herbs of Scorzonera austriaca Wild by silica gel column chromatography and preparative HPLC. Their structures were identified, using chemical and spectroscopic methods, as 5,7,4′-trihydroxyflavone 6-C-(2''-O-β-d-glucopyranosyl β-d-glucopyranoside) (1), 5,7,3′,4′-tetrahydroxyflavone 6-C-(2''-O-β-d-glucopyranosyl β-d-glucopyranoside) (2), quercetin 3-O-rutinoside (3), 5,7,4′-trihydroxyflavone 6-C-β-d-glucopyranoside (4), 3′-methoxy-5,7,4′-trihydroxyflavone 6-C-β-d-glucopyranoside (5), 5,7,4′-trihydroxyflavone 8-C-(6''-O-trans-caffeoyl β-d-glucopyranoside) (6), and 5,7,3′,4′-tetrahydroxyflavone 8-C-(6''-O-trans-caffeoyl β-d-glucopyranoside) (7). Compounds 6 and 7 are new flavonoid glycoside derivatives, and compounds 15 were isolated from the herbs of Scorzonera austriaca for the first time. Compounds 6 and 7 were also assayed for their hepatoprotective activities with rat hepatocytes in vitro. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis and Characterization of a Novel Borazine-Type UV Photo-Induced Polymerization of Ceramic Precursors
Molecules 2016, 21(6), 801; https://doi.org/10.3390/molecules21060801
Received: 20 March 2016 / Revised: 25 May 2016 / Accepted: 7 June 2016 / Published: 21 June 2016
Cited by 2 | PDF Full-text (2686 KB) | HTML Full-text | XML Full-text
Abstract
A preceramic polymer of B,B′,B′′-(dimethyl)ethyl-acrylate-silyloxyethyl-borazine was synthesized by three steps from a molecular single-source precursor and characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectrometry. Six-member borazine rings and acrylate groups were effectively introduced into the preceramic polymer to activate
[...] Read more.
A preceramic polymer of B,B′,B′′-(dimethyl)ethyl-acrylate-silyloxyethyl-borazine was synthesized by three steps from a molecular single-source precursor and characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectrometry. Six-member borazine rings and acrylate groups were effectively introduced into the preceramic polymer to activate UV photo-induced polymerization. Photo-Differential Scanning Calorimetry (Photo-DSC) and real-time FTIR techniques were adapted to investigate the photo-polymerization process. The results revealed that the borazine derivative exhibited dramatic activity by UV polymerization, the double-bond conversion of which reached a maximum in 40 s. Furthermore, the properties of the pyrogenetic products were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), which proved the ceramic annealed at 1100 °C retained the amorphous phase. Full article
(This article belongs to the Section Molecular Diversity)
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