Amorphastilbol,an antimicrobial agent from Amorpha nana

Bioassay-directed fractionation of Amorpha nana demonstrated that the anti Gram positive/antitubercular constituent is amorphastilbol. The chemical structure of amorphastilbol was confirmed by chemical transformation to known (Radula variabilis) dihydroamorphastilbol and its methyl ether. Inactive 3,5-dihydroxy-7,4′-dimethoxyflavone was detected in this plant for the first time and identified by interconversion with kaempferol. All compounds were evaluated in vitro for antimicrobial spectrum and potency.