- Polyphenols from the bark of Rhus verniciflua and their biological evaluation on antitumor and anti-inflammatory activities
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Bioassay-guided fractionation and chemical investigation of the extract of Rhus verniciflua bark resulted in the identification of six polyphenols, rhusopolyphenols A-F (1-6), together with four known compounds including (2R,3S,10S)-7,8,9,13-tetrahydroxy-2-(3,4-dihydroxyphenyl)-2,3-trans-3,4-cis-2,3, 10-trihydrobenzopyrano[3,4-c]-2-benzopyran-1-one (7), peapolyphenol C (8), cilicione-b (9) and (αR)- α,3,4,2',4'-pentahydroxydihydrochalcone (10). The structures of these polyphenols were elucidated by spectroscopic analysis, including 1D and 2D NMR, and HR-ESIMS, and their absolute configurations were further confirmed by a combination of chemical methods and CD data analysis. All isolates were evaluated for their antiproliferative activities against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15), and compounds 4-6, 9 and 10 showed antiproliferative activity against the tested cells, with IC50 values of 3.31-18.51 μM. On the basis of the expanded understanding that inflammation is a crucial cause of tumor progression, the anti-inflammatory activities of these compounds were determined by measuring nitric oxide (NO) levels in the medium of murine microglia BV-2 cells. Compounds 5 and 10 significantly inhibited NO production in lipopolysaccharide (LPS)-stimulated murine microglia BV-2 cells with IC 50 values of 28.90 and 12.70 μM, respectively.
- Kim, Ki Hyun,Moon, Eunjung,Choi, Sang Un,Kim, Sun Yeou,Lee, Kang Ro
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p. 113 - 121
(2013/10/21)
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- Bioactive flavonoids of the flowers of Butea monosperma
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One new dihydrochalcone, dihydromonospermoside (7), was isolated from the flowers of Butea monosperma together with three known chalcones, butein (2), monospermoside (4) and isoliquiritigenin (8), one flavone, 7,3',4'- trihydroxyflavone (6), four flavanon
- Chokchaisiri, Ratchanaporn,Suaisom, Channarong,Sriphota, Siriluk,Chindaduang, Anon,Chuprajob, Thipphawan,Suksamrarn, Apichart
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experimental part
p. 428 - 432
(2009/12/27)
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- Antioxidant study and assignments of NMR spectral data for 3′,4′,7-trihydroxyflavanone 3′,7-Di-O-β-D-glucopyranoside (butrin) and its hydrolyzed product
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The NMR spectral data including high resolution 1H, 13C and 2D NMR for butrin, 3′,4′,7-trihydroxyflavanone 3′,7-di-O-β-D-glucopyranoside, isolated from flowers of Butea monosperma, are reported here for the first time. Butrin was hydrolyzed using b-glucosidase to butin in high yield. They were subjected to free radical scavenging test using 2,2-diphenyl-1-picrylhydrazyl (DPPH) spectrophotometric assay. At a dose of 4 × 10-8 mol of tested compounds, the percentage of reduced DPPH for butin was 14.5% while no reduction was observed for butrin (0%).
- Jassbi, Amir Reza,Singh, Pahup,Krishna, Vivek,Gupta, Pradeep K.,Tahara, Satoshi
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p. 250 - 253
(2007/10/03)
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- Photochemical Deoxygenation of an α-Ketol: The Dihydroflavonol-Flavanone Conversion
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Irradiation of optically pure 2,3-trans-3-hydroxyflavanones in anhydrous ethyl acetate leads directly to free phenolic flavanone analogues with complete retention of configuration at C(2).Similarly their methyl ethers give the corresponding flavanones and flavones.The reaction represents the photochemical equivalent of a reduction under Clemmensen conditions.
- Westhuizen, Jan H. van der,Ferreira, Daneel,Roux, David G.
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p. 1003 - 1006
(2007/10/02)
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