A new clerodane diterpene, Caseargrewiin M (1), and one known compound (2) were isolated from fresh ripe fruits of Casearia grewiifolia. The structures of all isolated compounds were evaluated on the basic 1D (H and C) and 2D NMR (COSY, HSQC, HMBC and NOESY) spectral data. All compounds were examined cytotoxicity with five human cancer cell lines, Hep-G2 (hepatocarcinoma), SW620 (colon adenocar...