title: Xanthine oxidase inhibiting flavonol glycoside from Amberboa ramosa.
abstract: A new flavonol glycoside (1) has been isolated from the ethyl acetate soluble fraction of Amberboa ramosa and assigned the structure 5,7,4'-trihydroxy-3,8-dimethoxylflavone 5-O-beta-D-gluco-pyranoside (1). In addition, 6,4'-dihydroxy-3,5,7-trimethoxyflavone (2), 5,7-dihydroxy-4'-methoxyflavone (3) and (23R)-5alpha-cycloart-24-ene-3beta,21,23-triol (4) have also been reported for the first time from this species. The structures were deduced on the basis of 1D and 2D NMR techniques. The compounds 1-3 displayed weak to moderate inhibition against the xanthine oxidase enzyme.
authors.affiliation: International Centre for Chemical Sciences, HEJ Research Institute of Chemistry, University of Karachi, Pakistan.
authors.forename: Sher Bahadar
authors.initials: SB
authors.lastname: Khan
authors.forename: Nighat
authors.initials: N
authors.lastname: Afza
authors.forename: Abdul
authors.initials: A
authors.lastname: Malik
authors.lastname: Azhar-Ul-Haq
authors.forename: Shagufta
authors.initials: S
authors.lastname: Perveen
authors.forename: Ijaz
authors.initials: I
authors.lastname: Ahmad
authors.forename: Asma
authors.initials: A
authors.lastname: Ejaz
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: C512660:5,7,4'-trihydroxy-3,8-dimethoxylflavone 5-O-beta-D-gluco-pyranoside; D047309:Flavones; D006027:Glycosides; D014969:Xanthine Oxidase