Solenopsin is a lipophilic alkaloid with the molecular formula CHN found in the venom of fire ants (Solenopsis).  It is considered the primary toxin in the venom and may be the component responsible for the cardiorespiratory failure in people who experience excessive fire ant stings.
Structurally solenopsins are a piperidine ring with a methyl group substitution at position 2 and a long hydrophobic chain at position 6.  They are typically oily at room temperature, water-insoluble, and present an absorbance peak at 232 nanometers. Fire ant venom contains other chemically related piperidines which make purification of solenopsin from ants difficult.  Therefore, solenopsin and related compounds have been the target of organic synthesis from which pure compounds can be produced for individual study.  Originally synthesized in 1993, several groups have designed novel and creative methods of synthesizing enantiopure solenopsin and other alkaloidal components of ant venom.