Isohalitulin and Haliclorensins B and C, Three Marine Alkaloids from <i>Haliclona tulearensis</i>

Abstract

Three new alkaloids, designated isohalitulin (4), haliclorensin B (5), and haliclorensin C (6), were isolated from two specimens of the Madagascan sponge Haliclona tulearensis, collected at two locations in Salary Bay, north of Tulear. Their structures were elucidated by extensive spectroscopic means. Alkaloids 4-6 exhibited mild toxicity in the brine shrimp test.