Bioactive Nortriterpenoids from Schisandra grandiflora.

Three new nortriterpenoids, schigrandilactones A-C (1-3), along with eight known compounds, were isolated from an organic solvent extract of Schisandra grandiflora. Compounds 1 and 2 feature a spirocyclic moiety in their structures, and compound 3 was characterized with a new oxygenated pattern. The relative configurations of 1 and 3 were determined through single-crystal X-ray experiments. In addition, compounds 1 and 2 displayed cytotoxic activity against two human cancer cell lines, and compound 3 showed anti-HIV-1 inhibition in infected C8166 cells.