New polar steroids from the sponges Trachyopsis halichondroides and Cymbastela coralliophila.

Fractions of trisulfated trihydroxysteroids from the sponges Trachyopsis halichondroides (two different collections) and Cymbastela coralliophila have been isolated and investigated. Ten triacetates were obtained from these fractions by desulfatation/acetylation followed by chromatographic separation, and their structures have been established. Four of these derivatives--namely, triacetates of 5 alpha-pregnane-2 beta,3 alpha,6 alpha-triol (3c), 23,24-dinor-5 alpha-cholane-2 beta,3 alpha,6 alpha-triol (4c), 5 alpha-cholest-22-ene-2 beta,3 alpha,6 alpha-triol (7c), and 24-isopropyl-5 alpha-cholestane-2 beta,3 alpha,6 alpha-triol (11c)-- are described as new derivatives of natural steroids.