Two new 4-methylidene containing steroids, craterol A and B, from the New Zealand two sponge association between Stelletta crater and Desmacella dendyi

Abstract

&NA; NMR‐directed investigation of the two sponge association between Stelletta crater and Desmacella dendyi has resulted in the isolation of two new members of the rare 4‐methylidene class of sterols. Craterol A (1) and B (2) represent the first examples of natural products reported from the species S. crater. The isolation of these compounds challenges the role of 4‐methylidene sterols as chemotaxonomic markers for the sponge genus Theonella.