title: Biotransformation of polymethoxylated flavonoids: access to their 4'-O-demethylated metabolites.
abstract: Regioselective O-demethylation of the flavones tangeretin (1) and 3-hydroxytangeretin (6) into their 4'-O-demethylated metabolites was performed by using an Aspergillus niger strain. This method serves as a straightforward alternative to multistep synthesis or semisynthesis. The microbial approach is complementary to the chemical procedure, which furnishes a 5-O-demethylated product. P450 inhibitors prevented the biotransformation of tangeretin (1). These results suggest that a P450 oxidation system might be involved in this O-demethylation and demonstrate a consequent similarity in both microbial and mammalian metabolism of polymethoxylated flavones.
authors.affiliation: Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS, 45 Rue des Sts Pères, 75006 Paris, France. didier.buisson@univ-paris5.fr
authors.forename: Didier
authors.initials: D
authors.lastname: Buisson
authors.forename: Jérôme
authors.initials: J
authors.lastname: Quintin
authors.forename: Guy
authors.initials: G
authors.lastname: Lewin
mesh_terms: D001234:Aspergillus niger / Q000737:chemistry / Q000378:metabolism*; D001711:Biotransformation; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D015394:Molecular Structure
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D047309:Flavones; D003577:Cytochrome P-450 Enzyme System; C059006:tangeretin