BIOSYNTHESIS OF ISOPRENOID COMPOUNDS IN SCHISTOSOMA-MANSONI

The isoprenoid biosynthetic capacity of digenetic trematodes was inves tigated by following the fate of [C-14]mevalonic acid incorporated by Schistosoma mansoni during maintenance in axenic culture. Isoprenoid c ompounds were analyzed by thin-layer chromatography and high-performan ce liquid chromatography. Of the nonsaponifiable lipid classes, radioa ctivity was recovered in the dolichols, ubiquinones and in the short-c hain isoprenoid alcohols. The latter group of lipids included geraniol , farnesol, geranylgeraniol and a compound tentatively identified as 2 ,3-dihydrogeranylgeraniol. Radioactivity derived from [C-14]mevalonate was also incorporated into the saponifiable lipids, with 2,3-dihydrog eranylgeranoic acid accompanied by much less geranylgeranoic acid bein g detected in the triacylglycerol-containing fraction. Similarly, gera nylgeraniol and the dihydro derivative were also detected as esters, p resumably with fatty acids. The possible significance of the results i s discussed.