title: Microbial metabolism part 9. Structure and antioxidant significance of the metabolites of 5,7-dihydroxyflavone (chrysin), and 5- and 6-hydroxyflavones.
abstract: 5,7-Dihydroxyflavone (chrysin) (1) when fermented with fungal cultures, Aspergillus alliaceous (ATCC 10060), Beauveria bassiana (ATCC 13144) and Absidia glauco (ATCC 22752) gave mainly 4'-hydroxychrysin (4), chrysin 7-O-beta-D-4-O-methylglucopyranoside (5) and chrysin 7-sulfate (6), respectively. Mucore ramannianus (ATCC 9628), however, transformed chrysin into six metabolites: 4'-hydroxy-3'-methoxychrysin (chrysoeriol) (7), 4'-hydroxychrysin (apigenin) (4) 3',4'-dihydroxychrysin (luteolin) (8), 3'-methoxychrysin 4'-O-alpha-D-6-deoxyallopyranoside (9), chrysin 4'-O-alpha-D-6-deoxyallopyranoside (10), and luteolin 3'-sulfate (11). Cultures of A. alliaceous (ATCC 10060) and B. bassiana (ATCC 13144) metabolized 5-hydroxyflavone (2) into 5,4'-dihydroxyflavone (12) and 4'-hydroxyflavone 5-O-beta-D-4-O-methylglucopyranoside (13), respectively. 6-Hydroxyflavone (3) was transformed into 6-hydroxyflavanone (14), flavone 3-O-beta-D-4-O-methylglucopyranoside (15) and (+/-)-flavanone 6-O-beta-D-4-O-methylglucopyranoside (16) by cultures of Beauveria bassiana (ATCC 13144). The structures of the metabolic products were elucidated by means of spectroscopic data. The significance of the metabolites as antioxidants in relation to their structure is briefly discussed.
authors: National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA.
authors: Wimal
authors: W
authors: Herath
authors: Julie Rakel
authors: JR
authors: Mikell
authors: Amber Lynn
authors: AL
authors: Hale
authors: Daneel
authors: D
authors: Ferreira
authors: Ikhlas Ahmad
authors: IA
authors: Khan
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D005658:Fungi / Q000378:metabolism*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared
chemical_list: D000975:Antioxidants; D005419:Flavonoids; C529356:6-hydroxyflavone; C043561:chrysin; C062711:5-hydroxyflavone