title: Side chain-hydroxylated sterols of the red alga Asparagopsis armata: significant products or artifacts due to autoxidation?
abstract: Sterols characterized by an allylic hydroxyl group in the side chain, such as stigmasta-5,28-diene-3 beta, 24 epsilon-diol (1), cholesta-5,23-diene-3 beta,25-diol (2) and cholesta-5,25-diene-3 beta,24 epsilon-diol (3), have been identified several times in various marine algae. Their origin was considered as doubtful: they could have been bona fide constituents of the alga, or be artifacts caused by autoxidation during the isolation process. We have shown that the dihydroxy steroids 2 and 3 can indeed be produced by the autoxidation of cholesta-5,24-dien-3 beta-ol (desmosterol) (5), but that they are nevertheless present in the taxonomic significance.
mesh_terms: D002775:Cholestadienols / Q000032:analysis; D003897:Desmosterol / Q000378:metabolism; D010840:Phytosterols / Q000032:analysis*; D000461:Rhodophyta / Q000032:analysis*
chemical_list: D002775:Cholestadienols; D010840:Phytosterols; D003897:Desmosterol