In the parasitic assays, the majority of compounds
tested exhibited slightly more potent activity towards L. donovani
than towards the other parasites. In general, the compounds
appeared to be more toxic towards P388 leukaemia
cells than towards primary mammalian L6 cells. 3-Acylpyrones
7 and 10 were the most active leishmanicidal compounds
detected in the present study (IC50s 0.46 and 0.55 mg/mL, respectively).