Flindersiamine, a furoquinoline alkaloid from Vepris uguenensis (Rutaceae) as a synergist to pyrethrins for the control of the housefly, Musca domestica L. (Diptera: Muscidae)

Bioassay-guided fractionation of a CHCl3/MeOH extract of the root barks of Vepris uguenensis resulted in the isolation of a known compound flindersiamine, a furoquinoline alkaloid. Column chromatography of the CHCl3/MeOH extract of the root barks of V. uguenensis yielded six semi-pure fractions V1-V6. Fraction V1, V2 and V3 exhibited synergism to the unsynergised pyrethrins (0.1%) against the housefly, M. domestica L., in a modified Kearns and Match spray test chamber. Extensive column chromatographic analysis of fraction V1, the most active fraction in synergising pyrethrins, furnished flindersiamine, 1 a known furoquinoline alkaloid whose structure was established by comparing its FTIR, 1H-NMR and 13C-NMR with those in the chemical literature