LONG-CHAIN AND VERY LONG-CHAIN METHYL-BRANCHED ALCOHOLS AND THEIR ACETATE ESTERS IN PUPAE OF THE TOBACCO HORNWORM, MANDUCA-SEXTA

Four homologous series of very long-chain methyl-branched alcohols (VLMA, C38 to > C44) were found in the internal lipids of developing male pupae of the tobacco hornworm, Manduca sexta, both as free alcohols and as acetate esters. The four major homologous series, with carbon chain backbones of 36-44 carbon atoms, consisted of a monomethyl, two dimethyls and a trimethyl-branched alcohol series. The major alcohol of each homologous series (with the corresponding alkane obtained by reduction in parentheses) was identified as 24-methyltetracontan-1-ol (17-methyltetracontane), 24,28-dimethyltetracontan-1-ol (13,17-dimethyltetracontane), 22,34-dimethyloctatriacontan-1-ol (5,17-dimethyloctatriacontane) and 22,26,34-trimethyloctatriacontan-1-ol (5,13,17-trimethyloctatriacontane). The minor components of the VLMA had backbones with an odd number of carbon atoms (37, 39, 41, and 43). Methyl branches of the minor components were identified on the 18- and 14,18-positions when numbered from the alkyl end of the chain. Also identified were minor amounts of long-chain methyl-branched alcohols (LMA, C25 to C32). The major components in the "wax ester" TLC fraction were acetate esters of the LMA and VLMA.