Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2009
Publication Date: 3/27/2009
Citation: Chen, J., Cantrell, C.L., Shang, H., Rojas, M.G. 2009. Piperideine Alkaloids from the Poison Gland of the Red Imported Fire Ant (Hymenoptera: Formicidae). Journal of Agricultural and Food Chemistry. 57:3128-3133.
Interpretive Summary: The red imported fire ant, Solenopsis invicta Buren, is a serious pest affecting humans, wildlife, crops, and livestock. Due to its vicious stings, red imported fire ant is a significant threat to public health. The painful sting may cause persistent local reaction or anaphylaxis which sometime results in death. We have identified six new piperideine alkaloids in fire ant poison gland extractions. This research finding is important for understanding the mechanism of human reactions to fire ant stings and developing medical treatments for fire ant stings.
Technical Abstract: It is well known that the major chemical components in the venom of the red imported fire ants, Solenopsis invicta Buren, are 2-methyl-6-alkyl or alkenyl piperidines. After isolating the extracts of poison glands and whole worker bodies with a column chromatography, we have obtained fractions containing a mixture of six piperideine alkaloids. Reduction of those samples using NaBH4 in ethanol generated piperidine alkaloids found in the fire ant poison gland. Apparently, NaBH4 reduction broke the C=N double in the piperideine ring, resulting in both the cis and trans piperidine alkaloids. Due to numerous investigations, the mass spectra and gas chromatographic behavior of most piperidine alkaloids in the fire ant venom have been well characterized, which significantly facilitates the identification of these piperdeine compounds. Based on the mass spectra and profiles of NaBH4 reduction products, we identified these piperideine alkaloids as 2-methyl-6-tridecenyl-6-piperideine, 2-methyl-6-tridecyl-6-piperideine, 2-methyl-6-pentadecenyl-6-piperideine, 2-methyl-6-pentadecyl-6-piperideine, 2-methyl-6-heptadecenyl-6-piperideine, and 2-methyl-6-heptadecyl-6-piperideine. It was the first time these piperideine alkaloids were reported in the red imported fire ant poison glands.