title: Hydroxylations and methylations of quercetin, fisetin, and catechin by Streptomyces griseus.
abstract: Preparative-scale biotransformation of quercetin (1), fisetin (7), and (+)-catechin (12) with Streptomyces griseus (ATCC 13273) resulted in the isolation and characterization of nine known hydroxylated and/or methylated (2--6, 8, 9, 11, 13a) metabolites and two previously unknown (10 and 14) metabolites. S.griseus catalyzed aromatic hydroxylations of rings A and B of quercetin and fisetin. Mono- and dimethoxy ring-B metabolites were obtained with all three substrates. Methylation appeared to occur only when catechol functional groups were present. Metabolite structures were established by FABMS, EIMS, and 1D and 2D NMR analysis.
authors.affiliation: Division of Medicinal and Natural Products Chemistry, Center for Biocatalysis and Bioprocessing, College of Pharmacy, The University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hosny
authors.forename: K
authors.initials: K
authors.lastname: Dhar
authors.forename: J P
authors.initials: JP
authors.lastname: Rosazza
mesh_terms: D002392:Catechin / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism*; D044948:Flavonols; D006900:Hydroxylation; D008745:Methylation; D011794:Quercetin / Q000378:metabolism*; D013057:Spectrum Analysis; D013302:Streptomyces / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D044948:Flavonols; D002392:Catechin; D011794:Quercetin; C017875:fisetin