Cytotoxic cardenolides and antibacterial terpenoids from crossopetalum gaumeri

From the methanol extract of the roots of Crossopetalum gaumeri, four new highly cytotoxic cardenolides, securigenin-3β-O-β-6-deoxyguloside (2), 19-hydroxy-sarmentogenin-3β-O-β-6-deoxyguloside (4), sarmentogenin-3β-O-[α-allosyl-(1→4)-β-6-deoxyalloside] (5), and securigenin-3β-O-[α-allosyl-(1→4)-β-6-deoxyalloside] (6) were isolated. The dichloromethane extract afforded the new diterpene 3,15-dihydroxy-18-norabieta-3,8,11,13-tetraene (7) as well as the new triterpene 2,3,7-trihydroxy-6-oxo-1,3,5(10),7-tetraene-24-nor-friedelane-29-oic acid methylester (11). The new terpenoids lack cytotoxicity and the antibacterial activity is moderate to low.