Two new scalarane sesterterpenes: isoscalarafuran-A and -B, epimeric alcohols from a southern Australian marine sponge, Spongia hispida.

Abstract

A specimen of the marine sponge Spongia hispida (Lamarck, 1814), collected in the Great Australian Bight, has yielded the known sesterterpene hyrtiosal, together with two new scalarane sesterterpenes, isoscalarafuran-A (I) and isocalarafuran-B (II). The structures for these two new metabolites were secured by detailed spectroscopic anal., comparison with model compds., and mol. modeling.