New nor-clerodane-type furanoditerpenoids from the rhizomes of Tinospora capillipes

Three new nor-clerodane-type furanoditerpenoids, tinocapillins A–C ( 1 – 3 ), and three known diterpenoids were isolated from the rhizomes of Tinospora capillipes . Their structures were elucidated on the basis of extensive spectroscopic analysis. The absolute configuration of compound 4 was established by single-crystal X-ray diffraction analysis using Cu Kα radiation. Compounds 1 , 2 , and 5 exhibited moderate inhibitory activity on the proliferation of the A549, Hep G2, Hela, and OS-RC-2 human cancer cell lines.