ELUCIDATION OF DIMETHYLALKYLPYRAZINES FROM THE ANT STREBLOGNATHUS-AETHIOPICUS BY GC-FTIR

The presumed mandibular gland secretions from the workers and gamergat es of two colonies of Streblognathus aethiopicus have been found to co ntain a homologous series of 3,5-dimethyl-2-alkylpyrazines (3,5-dimeth yl-2-butylpyrazine, 1; 3,5-dimethyl-2-pentylpyrazine, 2; and 3,5-dimet hyl-2-hexylpyrazine, 3). The structures of these compounds were determ ined from their mass spectra along with a comparison of their GC-FTIR spectra with those of all the isomers of a lower homolog. This is the first time that this combination of techniques has been applied to the study of insect pyrazines. The relative amounts and proportions of th ese compounds were different for gamergates and workers, with the latt er containing 2-10 times more total pyrazines and having a higher prop ortion of 2 and 3. The possible significance of this finding is discus sed.