New 1,3 dibenzyl -tetrahydropyridinylidene ammonium salts have been prepared from unsubstituted or N-benzylated tetrahydropyridinylidene ammonium salts. The antiplasmodial and antitrypanosomal activities as well as their cytotoxic effects were determined using microplate assays. In addition, their activities against two gram positive and two gram negative bacteria strains and a yeast strain were examined. Furthermore, anticancer effects against two cell lines were investigated. Physicochemical parameters were calculated and structure-activity-relationships discussed. One compound showed antiplasmodial activity against a multiresistant strain of Plasmodium falciparum in subnanomolar concentration. Antitrypanosomal activities were detected in low nanomolar concentrations. A single compound was active against grampositive and gramnegative bacteria, as well as yeast. One compound inhibited the growth of a HCT cell line in low concentration.

New derivatives of 3-azabicyclo[3.2.2]nonanes were prepared and characterized using FT-IR spectroscopy, HRMS, and NMR spectroscopy. The new compounds were investigated in vitro for their antiplasmodial activities against the sensitive NF54 strain and the multiresistant K 1 strain of Plasmodium falciparum , and for their antitrypanosomal activity against Trypanosoma brucei rhodesiense . The N -methyl-6,9-diphenyl- N -[(pyridin-4-yl)methyl]-3-azabicyclo[3.2.2]nonan-1-amine possessed high antiplasmodial in vitro activity against both strains of P. falciparum (NF54: IC50 = 0.848 nm; K 1 : IC 50 = 2 nm). The most promising ones were further investigated in a mouse model for their in vivo activity against Plasmodium berghei . Graphic abstract