Thalicosides A1-A3, minor cycloartane bisdesmosides from Thalictrum minus

Three new cycloartane bisdesmosides, two of which are based on a new genin, were isolated from the above-ground parts of Thalictrum minus. Thalicosides A1-A3 (1-3) were characterized as 3-O-beta-D-galactopyranosyl-29-O-beta-D-glucopyranosyl-3 beta,16 beta,29-trihydroxy-22(S),25-epoxycycloartane (1); 3-O-alpha-L-arabinopyranosyl-29-O-beta-D-glucopyranosyl-3 beta,16 beta,29,22(S)-tetrahydroxycycloart-24-ene (2); and 3-O-alpha-L-arabinopyranosyl-29-O-beta-D-glucopyranosy-3 beta,16 beta,29-trihydroxy-22(S),25-epoxycycloartane (3), respectively. The structural assignments of these new compounds were based on interpretation of spectroscopic data. Thalicoside A2 showed in vitro inhibition of the fungus Candida albicans and also activity against Staphylococcus aureus.