New Lignans from the Leaves and Stems of Schisandra chinensis and Their Anti-HIV-1 Activities

Six new lignans (1-6), as well as five known ones (7-11) were isolated from the leaves and stems of Schisandra chinensis. The structures of 1-6 were established on the basis of spectroscopic methods including 1D-and 2D-NMR techniques and CD experiments. Compound 1 was the first example of naturally occurring N-containing lignans featuring a nicotinoyl group. All the new compounds were evaluated for their anti-HIV-1 activities and showed EC50 values in the range 17.89-138.23 mu g/mL.