Alkyl-Dimethylpyrazines in Mandibular Gland Secretions of Four Odontomachus Ant Species (Formicidae: Ponerinae)

• Published in: Journal of chemical ecology Vol. 44; no. 5; pp. 444 - 451
• Main Authors: Xu, Sihang, Errabeli, Ramu, Feener, Donald H., Noble, Katherine, Attygalle, Athula B.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2018; Springer Nature B.V
• Subjects: Agriculture; Alkylation; Animals; Ants - chemistry; Ants - physiology; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Chemical ecology; Ecology; Entomology; Gas chromatography; Gas Chromatography-Mass Spectrometry; Glands; Insects; Isomerism; Isomers; Life Sciences; Mandibular gland; Mass spectrometry; Mass spectroscopy; Methylation; Odontomachus; Pheromones - analysis; Pheromones - metabolism; Pyrazines; Pyrazines - analysis; Pyrazines - metabolism; Secretions; Species; Species Specificity; Spectra; Volatile compounds; Volatiles; Alkylpyrazines; Retention indices; Pheromones; Odontomachus erythrocephalus; Odontomachus chelifer; Odontomachus bauri; Odontomachus ruginodis
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1007/s10886-018-0948-y

Ponerine ants are known to contain mixtures of pyrazines in their mandibular glands. We analyzed the mandibular gland contents of four ponerine species ( Odontomachus chelifer, O. erythrocephalus, O. ruginodis , and O. bauri ) by gas chromatography coupled with mass spectrometry, and found that each species contains specific mixtures of trisubstituted alkylpyrazines among other volatiles. Attempts to identify alkylpyrazines solely by mass spectral interpretation is unrealistic because spectra of positional isomers are indistinguishable. To avoid misidentifications, we synthesized a large number of reference compounds and compared their mass spectral and gas chromatographic properties with those present in the Odontomachus species under investigation. Most of the compounds identified were 2-alkyl-3,5-dimethylpyrazines. Interestingly, when the third substituent was an isopentyl group, the two methyl groups were found to be located at the 2 and 5 ring positions. Using our data, we recognized several misidentifications in previous publications.