Anticoccidial activity of salinomycin derivatives.

In the course of our studies concerning the derivatization of the polyether ionophore nigericin1'2) we observed a dependence of the antibacterial activity on the counter ion at C-l,3) which prompted us to investigate if related effects can also be found for other polyethers and indications. Salinomycin (1), for example is another important polyether4'5) which is produced in combination with related analogs -by fermentation of Streptomyces albus.6) Compound 1 is commercially applied as feed additive for the prophylaxis against coccidiosis of broiler chicken. Furthermore, an antibacterial, antiviral activity and effect on food utilization in ruminants is noteworthy.4)6'7) Its mode of action is probably related to the ionophoric properties. Hitherto, only the antibacterial activities of