Butenolides from Marchantia paleacea subspecies diptera

Two new unstable long-chain lipids containing a gamma-lactone ring have been isolated from a diethyl ether extract of Japanese Marchantia paleacea subsp. diptera, in addition to caryophyllene oxide and (+)-7,13-labdadien-15-ol. Their structures were established by extensive 2D NMR techniques. They were shown to be 2-(8'Z,11'Z-hexadecadienyl)-penta-2,4-dien-4-olide and 2-(8'Z-hexadecenyl)-penta-2,4-dien-4-olide. This is the first report of the isolation of long-chain butenolides from liverworts, although they have been isolated previously from the gorgonians Plexaura flava and Euplexaura flava. (C) 1997 Elsevier Science Ltd.