BIOSYNTHESIS OF THE CUTICULAR HYDROCARBONS OF THE TERMITE ZOOTERMOPSIS-ANGUSTICOLLIS (HAGEN) - INCORPORATION OF PROPIONATE INTO DIMETHYLALKANES

The biosynthesis of hydrocarbons was investigated in the termite Zootermopsis angusticollis. Labelled acetate and propionate were readily incorporated into the cuticular hydrocarbons of this insect, with the soldier and worker castes incorporating these substrates into hydrocarbon more efficiently than nymphs. Palmitate was incorporated into hydrocarbon by workers to about the same extent as acetate. Analysis of the radioactive products by radio-GLC showed that acetate was incorporated at appreciable levels into each of the major components of the hydrocarbon fraction. In contrast, palmitate preferentially labelled the η-alkanes and propionate preferentially labelled the methyl branched components. Of the [1-14C]-propionate that was incorporated into hydrocarbon by nymphs, 24.6 ± 4.5% of the radioactivity was recovered in 5-methylheneicosane and 54.9 ± 8.4% in 5,17-dimethylheneicosane. Similar data were obtained in the worker and soldier castes. These data suggest that the branching methyl groups of both the mono- and dimethylalkanes arise from the incorporation of propionate in place of acetate during chain elongation. © 1979.