New derivatives of benzimidazole and their antimicrobial activity

Azolium salts and neutral 2-aryl derivatives of benzimidazole, benzothiazol e and benzoxazole were synthesized and compounds were identified by H-1 and C-13 NMR spectroscopy and microanalytical methods. In this work the salts I and the neutral compounds 2 were evaluated for their in vitro antimicrobi al activity against standard strains: Enterococcus faecalis (ATCC 29212), S taphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomon as aeruginosa (ATCC 27853), Candida albicans and Candida tropicals. The compounds If, Ig, Il, Im, In, 2a, 2b, 2c, 2e, 2f showed antimicrobial a ctivity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus ( ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27 853), Candida albicans and Candida tropicals, with minimum inhibitory conce ntrations (MICs) ranging between 50 to 200 mu g/mL. Compounds If, Ig, 11, I m, 2b, 2e showed the highest activity. Benzothiazolium and benzoxazolium sa lts were more active than 1,3-disubstituted benzimidazolium salts and neutr al 2-substituted benzimidazole, benzothiazole and benzoxazole derivatives.