The activity of diploceline is relatively weak as compared to metronidazole on Entamoeba histolytica and Trichomonas vaginalis. The quaternary alkaloid does not produce any inhibition of Plasmodium falciparum growth at 25 micrograms/ml (maximum tested concentration).
Gasquet, M., Leclercq, J., Timon-David, P., Balansard, G., & Angenot, L. (1992). Antiparasitic properties of diploceline, a quaternary alkaloid from Strychnos gossweileri. Planta Medica : natural products and medicinal plant research, 58(3), 276-277. https://doi.org/10.1055/s-2006-961454 (Original work published 1992)