Five new (1-3, 5, and 7) and two known (4, 6) furanosesterterpene tetronic
acids were isolated from the marine sponge Sarcotragus sp. by bioactivity-g
uided fractionation. These compounds showed cytotoxicity against a panel of
five human tumor cell lines. The gross structures were established on the
basis of NMR and MS analyses. The compounds showed interesting variations o
f geometry and absolute configuration.