Four New Lignans from Kadsura Interior and Their Bioactivity.

A phytochemical investigation of the stems of Kadsura interior has led to an isolation of four new lignans, named kadsutherin E⁻H (1⁻4), together with two known lignans (5⁻6). The structures of the four new compounds were established on the basis of comprehensive spectroscopic analyses. Compounds 1⁻6 exhibited inhibition against adenosine diphosphate (ADP) induced platelet aggregation. Among the isolated compounds, kadsutherin F (2) showed the strongest anti-platelet aggregation activity with an inhibition of 49.47%.