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-β-D-gluco-pyranoside (1). In addition, 6,4′-dihydroxy-3,5,7-trimethoxyflavone (2), 5,7-dihydroxy-4′-methoxyflavone (3) and (23R)-5α-cycloart-24-ene-3β,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.