Evidence for de novo biosynthesis of the polyketide fragment of diaulusterol A by the northeastern pacific dorid nudibranch diaulula sandiegensis.

Stable isotope incorporation experiments using sodium [1, 2-13C2]acetate have demonstrated that the 3-hydroxybutyrate substituent of diaulusterol A (1) is biosynthesized de novo by the dorid nudibranch Diaulula sandiegensis. There was no evidence for acetate incorporation into the steroid portion of 1, nor were radiolabeled mevalonate or cholesterol incorporated.