Sesquiterpenes from a New Zealand sponge of the Genus Eurypon

A cytotoxic sesquiterpene (1) with a tricyclo[6.3.1.0. 25 ]dodecane skeleton has been isolated from the extract of a New Zealand Eurypon sp. of sponge. Two derivatives, (2) and (3), of this sesquiterpene have also been isolated, probably as artefacts arising during the isolation procedure. The structure of a spiro sesquiterpene (4), also obtained from the sponge extract, has been determined. Previously published n.m.r. assignments for ß-caryophyllene alcohol (5) have been revised. © 1988 ASEG.