CYTOTOXIC 2,3-SECOAROMADENDRANE-TYPE SESQUITERPENOIDS FROM THE LIVERWORT PLAGIOCHILA-OVALIFOLIA

The ether extract of the Japanese liverwort, Plogiochila ovalifolio Mi tt. (Plagiochilaceae) yielded three 2,3-secoaromadendrane-type sesquit erpenoids, plagiochiline-A-15-yI octanoate, 14-hydroxyplagiochiline-A- 15-yl 2E,4E-dodecadienoate and (14)-hydroxyplagiochiline-A-15-yl 2E,4E ,8Z-tetradecatrienoate. The two latter compounds were first isolated f rom the Plagiochila species. The structures of the new compounds were elucidated by spectroscopy. Plagiochiline-A-15-yl octanoate and 14-hyd roxyplagiochiline-A-15-yl 2E,4E-dodecadienoate showed significant cyto toxicity against P-388 murine leukemia tumor cells, both compounds exh ibiting an ID50 of 0.05 mu g/ml. Plagiochiline A also showed cytotoxic activity. The ID50 was 3.0 mu g/ml.