Three new compounds from Kadsura longipedunculata

Two new tetrahydrofuran lignans, kadlongirins A and B (1, 2), a new cadinane-type sesquiterpenoid, 2,7-dihydroxy-11,12-dehydrocalamenene (3), together with seven known lignans, grandisin, fragransin B1, vladirol F, kadsuralignan C, otobaphenol, isoanwulignan, and 4-[4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl]-2-methoxy-phenol, were isolated from the leaves and stems of Kadsura longipedunculata. The structures of these new compounds were elucidated by spectroscopic methods. Compound 2 exhibited weak anti-human immunodeficiency virus-1 activity with an EC50 value of 16.0 microg/ml, and therapeutic index (TI) value of 6.7.