Dibenzocyclooctadiene lignans from the fruits of Schisandra rubriflora and their anti-HIV-1 activities.

Two new dibenzocyclooctadiene lignans, rubrilignans A and B (1, 2), together with 17 known ones, were isolated from the fruits of Schisandra rubriflora. The structures of 1 and 2 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-HIV-1 activities and showed weak anti-HIV-1 activity with EC(50) values of 2.26 and 1.82 μg/ml, and therapeutic index values of 35.5 and 18.6, respectively.