Abstract

Structural modification of the C-9154 antibiotic was carried out in an attempt to simultaneously improving its activity and lower its toxicity. An analogue of the C-9154 antibiotic and six derivatives of this analogue were synthesized. The approach was to significantly reduce the polarity of the analogue by structurally modifying it to get the derivatives in a bid to achieve increased permeability across cell membranes by conversion of the highly polar carboxylic group to an ester functional group. These compounds were synthesized by condensation of 2,4-dimethylaniline with maleic anhydride and then conversion of the terminal carboxylic acid functional group to an ester functional group using a thionyl chloride-mediated esterification process. The in vitro biological activity showed that the derivatives were more active than the analogue and significantly better than the standard drugs used for comparison. The compounds were fully characterized using Infrared, GC-MS and 1D and 2D NMR experiments.