Tigliane-Type Diterpenoid Glycosides from Euphorbia fischeriana

Investigation of whole plants of Euphorbia fischeriana afforded three new tigliane-diterpenoid glycosides, fischerosides A-C (1-3), together with 11 known diterpenoids. Fischerosides A-C (1-3) are the first tigliane-type diterpenoid glucosides. Their structures were determined by a combination of 1D and 2D NMR, MS, and acid hydrolysis. Inhibitory activity against HIV-1 was assessed for compounds 1-5. The new compound 3 showed an EC(50) value of 0.02 mu M and a therapeutic index (TI) of 17.50, while prostratin (4) and 12-deoxyphorbol-13,20-diacetate (5) showed significantly greater anti-HIV-1 activity.