- Synthesis of quercetin glycosides and their melanogenesis stimulatory activity in B16 melanoma cells
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4′-O-β-d-Glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl- (1→4)-β-d-glucopyra-noside (3) was isolated from Helminthostachys zeylanica root extract as a melanogenesis acceleration compound and was synthesized using rutin as the starting material Related compounds were also synthesized to understand the structure-activity relationships in melanin biosynthesis Melanogenesis activities of the glycosides were determined by measuring intracellular melanin content in B16 melanoma cells Among the synthesized quercetin glycosides, quercetin-3-O-β-d-glucopyranoside (1), quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (2), and 3 showed more potent intracellular melanogenesis acceleration activities than theophyline used as positive control in a dose-dependent manner with no cytotoxic effect
- Yamauchi, Kosei,Mitsunaga, Tohru,Batubara, Irmanida
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p. 937 - 944
(2014/02/14)
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- An expeditious synthesis of quercetin 3-O-β-d-glucuronide from rutin
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We report the synthesis of the major human metabolite of quercetin, quercetin 3-O-β-d-glucuronide, from rutin (quercetin-3-rutinoside), which is commercially available at low cost. This straightforward synthesis is based on the key intermediate 3′,4′,5,7-tetra-O-benzyl-quercetin which is obtained in only two steps by the total benzylation of rutin followed by acid hydrolysis of the rutinoside residue. Glycosylation of the free 3 hydroxyl group by 1-bromo-3,4,6-tetra-O-acetyl-α-d-glucopyranoside yields the protected glucoside. TEMPO-mediated oxidation of primary alcohol on the deprotected glucoside gives access to the benzylated glucuronide. Removal of the benzyl groups which protect the quercetin hydroxyl groups by H2 (10% Pd/C) yields quercetin 3-O-β-d-glucuronide.
- Kajjout, Mohammed,Zemmouri, Rajae,Rolando, Christian
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p. 4738 - 4740
(2011/10/02)
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