Antimicrobial activity of basic cholane derivatives. Part IX.

Twenty new compounds derived from deoxycholic acid have been synthesized. They contain two basic functions: at C-24 (benzylamino, morpholino, diethanolamino, N,N-diethylethylenediamino, N-methylpiperazino) and at beta-C-3 (amino, methylamino, ethylamino, benzylamino). The compounds showed interesting antimicrobial activity, as expressed in terms of the low M.I.C. values (0.9-31-micrograms/ml) against five Gram(+) and four Gram(-) strains, two fungi and one yeast. The compounds inhibit the production of a fluorescent pigment in Pseudomonas aeruginosa: this result suggests that the ability to cross the bacterium cell membrane is the first step of activity. A discussion in terms of structure-activity relationship is reported.