Hydrocarbon constituents of three species of dolichoderine ants

Abstract

A comparative study of the hydrocarbon constituents, obtained by total extraction, from three species of dolichoderine ants of the genus, Iridomyrmex, is reported. Forty-three hydrocarbons were identified from I. purpureus (=detectus), the type of the genus. Major constituents formed five groups based on the odd-carbon numbered alkanes, C23, C25, C27, C29 and C31, and comprised the parent alkane, alkene, alkadiene and monomethylalkanes. For example, the C23 group comprised tricos-9-ene with tricosadiene, tricosane and 3-, 5-, 7- and 11-methyltricosane. Higher molecular weight dimethylalkanes were minor constituents. Of the 57 hydrocarbons characterized from I. nitidiceps, alkanes were minor or trace constituents. Heptadec-8-ene was the only major alkene. The four major groups of hydrocarbons were mono- and dimethyl-alkanes based on C29, C31, C33 and C35 parents. For example, the nonacosane derivatives included 7-, 11-, 13- and 15-methylnonacosane, with 13,17-; 15,19- and 7,15-dimethylnonacosane. Higher molecular weight trimethyl derivatives were present. Of the 51 hydrocarbons characterized from I. humilis, the Argentine ant, 26 were confirmed from a previous study. Lower molecular weight hydrocarbons were major constituents; odd-carbon numbered alkanes from C15 to C29 were predominant. Major alkenes were heptadec-7-ene and -8-ene, and nonadec-9-ene. Monomethylalkanes were minor constituents. Three 4-methylderivatives based on even-numbered parent alkanes, 4-methylhexacosane with 4-methy-yloctacosane from I. nitidiceps, and 4-methylhexadecane from I. humilis were trace constituents.