4466 J . Org. Chem., Vol. 44, No. 24, 1979 Registry No. la, 1,4417-01-7; lb, 5183-78-8; IC, 20383-28-2; Id, 1696-17-9; le, 613-934; If, 103-83-3; 2, 19312-06-2; 3a, 67448-06-0; 3b, 13440-22-7; 3c, 6641-72-1; 3d, 2728-04-3; 3e, 2170-09-4; 3f, 452548-8; 4, 71885-44-4.
Allbert I. Meyers,* Kathryn Lutomski Department of Chemistry Colorado State University Fort Collins, Colorado 80523 Received July 31, 1979
Dinoflagellate Sterols. 2. Isolation and Structure of 4-Methylgorgostanol from the Dinoflagellate Glenodinium folialceum Summary: The dinoflagellate Gonyaulax foliaceum was found to contain four sterols, which were isolated and identified as cholesterol, 24-demethyldinosterol, dinosterol, and 4-methylgorostanol. Sir: Dinoflagellates are unicellular organisms which along with diatoms and coccolithophores constitute what is commonly known as phytoplankton. Phytoplankton is the foundation for the food chain in the seas. Their distribution controls the whole pattern of life in the seas and is of great economic importance. In our search of the origin of unusual sterols that have been isolated from marine invertebrates, especially from sponges, the dinofl(age1lateG. foliaceum was investigated for its sterol compositions. The chloroform extract of the unialgal cultures of the G. foliaceum2 gave a residue which after saponification afforded a sterol fraction consisting of four major sterols [cholesterol, 24-deniethyldinosterol, dinosterol, and a new C31 sterol identified as 4-methylgorgostanol (l)]in the ratio R2
1:
1
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