Synthesis and Correlation of Aggregation and Antimicrobial Properties of Homochiral Quaternary Ammonium Bromides Derived from Camphoric Acid

Abstract

A group of homochiral quaternary ammonium salts bearing hydrophobic camphoric acid-derived moiety was synthesized and characterized. The aggregation properties of the prepared compounds were evaluated by surface tension measurements, and the critical micelle concentration (CMC) was calculated. The novel quaternary ammonium bromides were tested as antimicrobial and antifungal agents, and their minimal inhibitory concentration (MIC) was evaluated and compared to clinically used benzalkonium bromide (BAB). Correlation of MIC with CMC reveals that monomers of prepared cationic surfactants, instead of micelles, are primarily responsible for antimicrobial activity.

Advances in the Synthesis of Biologically Active Quaternary Ammonium Compounds

“…QACs 34a-c were found to be stronger antimicrobial agents compared to clinically used benzalkonium bromide. The most preferable activity was noticed for compound 34c (Tables 1 and 3) with 16 carbon atoms in the alkyl chain [47]. Mikláš et al reported the synthesis of new optically active amphiphilic QACs 34a-d bearing a hydrophobic camphor moiety (Scheme 20).…”

“…QAC 35g bearing a 14-carbon alkyl substituent was identified as the most efficient agent, highly active against a wide spectrum Scheme 20. Synthetic route to QAC-camphoric acid conjugates 34a-d [47].…”