FURTHER LUPANE LACTONES FROM KOKOONA-OCHRACEA

Additional new lupane lactones were isolated from the stem bark of Kok oona ochracea (Celastraceae). Their structures have been elucidated, t hrough the application of 1D and 2D nmr spectroscopic methods, as 20,2 9-dihydroxy-3-oxolupan-30,21alpha-olide (ochraceolide D) [1] and 28-hy droxy-3-oxolup-20(29)-en-30,21alpha-olide (ochraceolide E) [2]. These compounds and the mono- and di-acetates of ochraceolide D (4 and 5, re spectively) were evaluated for in vitro cytotoxic activity against P-3 88 murine lymphocytic leukemia cells and a panel of human cancer cell systems. Ochraceolide D [1) was significantly cytotoxic (ED50, 3.9 mug /ml) against human glioblastoma (U373) cells. Other compounds (4, 5, a nd 2) exhibited only a weak cytotoxic response in certain cancer cell lines.