Two New Cytotoxic Clerodane Diterpenoids from Casearia membranacea

Abstract

In addition to casearlucin A (3), two new clerodane diterpenes, caseamembrols A (1) and B (2) have been isolated from the leaves and twigs of Casearia membranacea by bioassay-guided fractionation. The structures of the new compounds were established on the basis of extensive 1D- and 2D-NMR spectroscopic analysis. Compounds 1—3 exhibited significant cytotoxicity against human prostate (PC-3) cancer cells.