- Phenolics from durian exert pronounced NO inhibitory and antioxidant activities
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Durian, known as the king of fruits, is native to Southeast Asia and popular in many countries. Bioactivity-guided fractionation of the peel of durian was applied to determine its bioactive constituents. Four novel phenolics, along with 16 known, were pur
- Feng, Jianying,Wang, Yihai,Yi, Xiaomin,Yang, Weimin,He, Xiangjiu
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p. 4273 - 4279
(2016/06/15)
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- New dammarane-type saponins from the roots of panax notoginseng
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Three new dammarane-type triterpenoid saponins, 1-3, were isolated and identified as (20S)-20-O-[β-D-xylopyranosyl-(1→6)-β-D- glucopyranosyl-(1→6)-β-D-glucopyranosyl]dammar-24-ene-3β, 6α,12β, 20-tetrol (1), (20S)-6-O-[(E)-but-2-enoyl-(1→6)-β- D-glucopyranosyl]dammar-24-ene-3β,6α,12β,20-tetrol (2), and (20S)-6-O-[β-D-xylopyranosyl-(1→2)-β-D-xylopyranosyl] dammar-24-ene-3β,6α,12β,20-tetrol (3) from the roots of Panax notoginseng (Burkill) F.H.Chen (Araliaceae). Their structures were elucidated on the basis of spectroscopic analyses, including 1D- and 2D-NMR techniques and HR-ESI-MS, as well as by acidic hydrolysis. Copyright
- Qiu, Li,Jiao, Yang,Huang, Gui-Kun,Xie, Ji-Zhao,Miao, Jian-Hua,Yao, Xin-Sheng
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p. 102 - 111
(2014/02/14)
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- Synthesis and biological evaluation of new carbohydrate-substituted indenoisoquinoline topoisomerase I inhibitors and improved syntheses of the experimental anticancer agents indotecan (LMP400) and indimitecan (LMP776)
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Carbohydrate moieties were strategically transported from the indolocarbazole topoisomerase I (Top1) inhibitor class to the indenoisoquinoline system in search of structurally novel and potent Top1 inhibitors. The syntheses and biological evaluation of 20 new indenoisoquinolines glycosylated with linear and cyclic sugar moieties are reported. Aromatic ring substitution with 2,3-dimethoxy-8,9-methylenedioxy or 3-nitro groups exerted strong effects on antiproliferative and Top1 inhibitory activities. While the length of the carbohydrate side chain clearly correlated with antiproliferative activity, the relationship between stereochemistry and biological activity was less clearly defined. Twelve of the new indenoisoquinolines exhibit Top1 inhibitory activity equal to or better than that of camptothecin. An advanced synthetic intermediate from this study was also used to efficiently prepare indotecan (LMP400) and indimitecan (LMP776), two anticancer agents currently under investigation in a Phase I clinical trial at the National Institutes of Health.
- Beck, Daniel E.,Agama, Keli,Marchand, Christophe,Chergui, Adel,Pommier, Yves,Cushman, Mark
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p. 1495 - 1512
(2014/03/21)
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- Alcohol-, diol-, and carbohydrate-substituted indenoisoquinolines as topoisomerase i inhibitors: Investigating the relationships involving stereochemistry, hydrogen bonding, and biological activity
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The DNA-relaxing enzyme topoisomerase I (Top1) can be inhibited by heterocyclic compounds such as indolocarbazoles and indenoisoquinolines. Carbohydrate and hydroxyl-containing side chains are essential for the biological activity of indolocarbazoles. The current study investigated how similar functionalities could be "translated" to the indenoisoquinoline system and how stereochemistry and hydrogen bonding affect biological activity. Herein is described the preparation and assay of indenoisoquinolines substituted with short-chain alcohols, diols, and carbohydrates. Several compounds (including those derived from sugars) display potent Top1 poisoning and antiproliferative activities. The Top1 poisoning activity of diol-substituted indenoisoquinolines is dependent upon stereochemistry. Although the effect is striking, molecular modeling and docking studies do not indicate any reason for the difference in activity due to similar calculated interactions between the ligand and Top1-DNA complex and ambiguity about the binding mode. A stereochemical dependence was also observed for carbohydrate-derived indenoisoquinolines. Although similar trends were observed in other classes of Top1 inhibitors, the exact nature of this effect has yet to be elucidated.
- Peterson, Katherine E.,Cinelli, Maris A.,Morrell, Andrew E.,Mehta, Akhil,Dexheimer, Thomas S.,Agama, Keli,Antony, Smitha,Pommier, Yves,Cushman, Mark
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experimental part
p. 4937 - 4953
(2011/09/21)
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- Antioxidant activity of a water-soluble polysaccharide purified from Pteridium aquilinum
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A water-soluble crude polysaccharide, obtained from fern Pteridium aquilinum, was fractionated by DEAE-Sepharose Fast-Flow column chromatography, and purified by Sephacryl S-400 HR column chromatography. The average molecular weight (Mw) of the purified polysaccharide (PLP) is 458,000 Da. The monosaccharide components of PLP were characterized by gas chromatography (GC), and the majority of the monosaccharide components was glucose (relative mass 58.1%) with low levels of galactose, mannose, rhamnose, and arabinose (relative mass 18.7%, 6.8%, 10.2%, and 6.1%, respectively). The Fourier-transform infrared spectra (FTIR) of PLP revealed typical characteristics of polysaccharides. On the basis of the ferric-reducing antioxidant power assay (FRAP), DPPH radical-scavenging, the superoxide radical assay, and self-oxidation of 1,2,3-phentriol assay, the antioxidant activities of PLP were investigated. The purified polysaccharide was demonstrated to have strong reductive power (FRAP value: 827.6 μmol/L), moderate scavenging activities against DPPH radicals (83.1%) and superoxide radicals (60.5%), and moderate inhibiting power for self-oxidation of 1,2,3-phentriol (52.4%).
- Xu, Wentao,Zhang, Fangfang,Luo, YunBo,Ma, Liyan,Kou, Xiaohong,Huang, Kunlun
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experimental part
p. 217 - 222
(2009/04/11)
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- Five furostanol saponins from fruits of Tribulus terrestris and their cytotoxic activities
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Two new furostanol saponins, terrestroside A, 3-O-{β-D-xylopyranosyl- (1 → 3)-[ β-D-xylopyranosyl(1 → 2)] β - D-glucopyranosyl(1 → 4)-[α-L-rhamnopyranosyl(1 → 2)] β- D-galactopyranosy}-26- O -β D-glucopyranosyl-L-5a-furost-20(22)-en-(25R)-3,26-diol (1) an
- Wang, Jue,Zu, Xuyu,Jiang, Yuyang
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experimental part
p. 1436 - 1444
(2010/04/23)
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- Isolation, structure determination, and sensory activity of mouth-drying and astringent nitrogen-containing phytochemicals isolated from red currants (Ribes rubrum)
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Application of chromatographic separation and taste dilution analyses recently revealed, besides a series of flavon-3-ol glycosides and (E)/(Z)-aconitic acid, four nitrogen-containing phytochemicals as the key astringent and mouth-drying compounds in red currants (Ribes rubrum). The isolation and structure determination of the astringent indoles 3-carboxymethyl-indole-1-N-β-D-glucopyranoside (1) and 3- methylcarboxymethyl-indole-1-N-β-D-glucopyranoside (2), as well as the astringent, noncya-nogenic nitriles 2-(4-hydroxybenzoyloxymethyl)-4-β-D- glucopyranosyloxy-2(E)-butenenitrile (3) and 2-(4-hydroxy-3- methoxybenzoyloxymethyl)-4-β-D-glucopyranosyloxy-2(E)-butenenitrile (4) by means of 1D/2D NMR, LC-MS/MS, and UV-vis spectroscopy are reported. The structures of compounds 1 and 2 were confirmed by synthesis. Using the recently developed half-tongue test, human recognition thresholds for the astringent and mouth-drying nitrogen compounds were determined to be between 0.0003 and 5.9 μmol/L (water). In particular, the extraordinarily low threshold of 0.0003 μmol/L evaluated for the indole 1 represents the lowest recognition threshold of any astringent phytochemical reported to date.
- Schwarz, Bernd,Hofmann, Thomas
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experimental part
p. 1405 - 1410
(2009/10/01)
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