Ombuin is an O-methylated flavonol, a type of flavonoid. It is the 4',7-O-methyl derivative of quercetin.
Ombuin can be found in species of the genus Erythroxylum. It can also be synthesized.Partial methylation of quercetin: Direct synthesis of tamarixetin, ombuin and ayanin. Koppaka V. Rao, Jacob A. Owoyale, Journal of Heterocyclic Chemistry, Volume 13 Issue 6, Pages 1293 - 1295 Ombuin 3-sulfate can be isolated from Flaveria chlorifolia.Ombuin 3-sulphate from Flaveria chloraefolia. Denis Barron and Ragai K. Ibrahim, Phytochemistry, Volume 27, Issue 7, 1988, pages 2362-2363,
Glycosides Ombuin-3-rutinoside can be isolated from Phytolacca dioica, the ombu tree. (German) Ombuin-3-O-rhamnosylglucoside can be found in Erythroxylum rufum.Flavonoids of Erythroxylum rufum and Erythroxylum ulei. Bruce A. Bohm, David W. Phillips and Fred R. Gander, J. Nat. Prod., 1981, volume 44, issue 6, pages 676–679, Other glycosides (ombuosides) : Ombuin 3-galactoside (C23H24O12, CAS number 69168-13-4) Ombuin 3-glucoside (C23H24O12, CAS number 158642-42-3)
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