Synthesis and antimicrobial activity of cholic acid hydrazone analogues

Synthesis and antimicrobial activity of cholic acid analogues 4a-t are reported. The synthesis of 4a-t was accomplished from ethylcholate 2. The hydrazone moiety was introduced via coupling of the cholic acide hydrazide (3) with appropriately functionalized aldehyde utilizing acetic acid as a catalyst. Quiet of interest in relation to the synthesized hydrazones is the formation of two rotamers s-cis E and s-trans E. Most compounds showed stronger antimicrobial activity against Gram-positive bacteria than Cefaclor and Cefixime. Compounds 4d, 4i and 4j indicated 15-fold stronger antimicrobial activities against Enterobacter faecalis compared to Cefaclor and Cefixime. Some of the synthesized compounds (e g 4a, 4c, 4d, 4i, and 41) reflected twofolds less activity against Escherichia coli relative to Cefixime.