Sterols isolated from Tubifex tubifex.

Four 3beta-hydroxysterols isolated from chloroform extract from Tubifex tubifex were shown to have the structures stigmast-23-en-3-ol, stigmast-7,14-dien-3-ol, 22-dehydrocholesterol, and 24 methylenecholesterol based on spectroscopic methods. Stigmasterol and beta-sitosterol were also investigated on the basis of mass spectral analyses and compared with known compounds.