Synthesis, Antibacterial and Antifungal Activities of Bifonazole Derivatives

Two series of chlorinated benzhydryl imidazole and triazole derivatives were synthesized and tested in vitro against representative strains of potent pathogenic bacteria (Staphylococcus aureus CIP 4.83, Escherichia hirae CIP 5855, Pseudomonas aeruginosa CIP 82118, Escherichia coli CIP 53126) and fungi (Aspergillus niger IP 1431.83, Candida albicans IP 48.72, Candida krusei IP 208.52, Trichophython rubrum IP 1657.86). Most of these compounds were devoid of any antimicrobial activity, but several of them inhibited T. rubrum with MIC values in the range of 0.125 to 32 µg/mL, similar or superior to those of bifonazole and clotrimazole, used as standard controls. The replacement of the imidazole ring with a triazole moiety in these compounds led to derivatives with less antifungal activity. A preliminary SAR was undertaken on the effect of the number and the position of chlorine atoms on the distribution of negative charge on the surface of some compounds on antifungal activity. Two series of bifonazole derivatives were synthesized and tested in vitro against representative strains of potent pathogenic bacteria and fungi. Several of them inhibited T. rubrum with MICs similar or superior to those of bifonazole and clotrimazole. A SAR study showed that the imidazole ring and the number as well as the position of chlorine atoms on the aromatic ring have notable effects on antifungal activity.