A New Biflavonoid and a New Triterpene from the Leaves of Garcinia Paucinervis and Their Biological Activities

A new biflavonoid, paucinervin K (1) and a new triterpene, 23-hydroxy-friedelin (2), together with eleven known compounds 3-13 were isolated from the leaves of Garcinia paucinervis. Their structures, including stereochemistry, were determined by spectroscopic analysis of NMR, MS, IR and ECD calculation and the octant rule. Some of the isolated compounds were tested for antiproliferative, α-glucosidase inhibitory and antioxidant activities in vitro. Compounds 1, 3, 4, 5 and 9 showed moderate preferential antioxidant and hypoglycemic activities. Compounds 3–6 and 9 exhibited potent growth inhibition against HepG-2 and PC-3 cell lines with IC50 values ranging from 1.02−10.05 μM.