Reduction of venom alkaloids in Solenopsis richteri×Solenopsis invicta hybrid: an attempt to identify new alkaloidal components.

The alkaloid chemistry of the venom of hybrid fire ant, Solenopsis richteri × Solenopsis invicta, was investigated using silica gel chromatography and GC-MS techniques. In addition to most cis alkaloids of parental species, S. richteri Forel and S. invicta Buren, the cis alkaloid fraction of the body extract of hybrid fire ants also contains five significant new alkaloids. Hydrogenation of the cis alkaloid fraction yielded only five piperidines, 4', 12', 12, 20', and 20. Sodium borohydride and lithium aluminum hydride selectively reduced C═N double bond in piperideine alkaloids to give a mixture of cis and trans piperidines. However, reduction of the five new components yielded several new peaks with much longer retention times and increasing molecular weights over 30. It is evident that the chemical identities of the five new peaks are quite different from those known piperidines or piperideines found in Solenopsis fire ants.