Sterols of Leishmania species. Implications for biosynthesis.

The major sterol of promastigotes of stocks of Leishmania tropica, L. donovani and 3 subspecies of L. mexicana has been identified as ergosta-5,7,24(28)-trien-3 beta-ol; and of an L. major stock as ergosta-7,24(28)-dien-3 beta-ol. 24-Methylcholesta-5,7,22-trien-3 beta-ol and 24-ethylcholesta-5,7,22-trien-3 beta-ol were minor constituents, and traces of ergosta-5,7,22,24(28)-tetraen-3 beta-ol and a C27-diene were also recognized in some species. Lanosterol and 4,4-dimethylcholesta-8,24-dien-3 beta-ol were detected in all species studied, and squalene was identified in a stock of L. tropica. The sterol composition of members of the genus Leishmania and the sterol biosynthetic pathways it implies are characteristic of yeast and other fungi.