Antibacterial and antimycotic activity of benzophenazine derivatives: an in vitro study

Introduction. Today, one of the urgent health problems is the increasing antibiotic resistance of pathogenic microorganisms. In this regard, there is an increasing need to find new antimicrobial agents for medical use. Benzophenazine derivatives may be an example of promising antimicrobial agents. This article presents a study of the antimicrobial properties of newly synthesized compounds of the benzophenazine group.

Aim: To evaluate the antibacterial and antifungal potential of benzophenazine derivatives under experimental conditions in vitro.

Material and Methods. The antimicrobial activity of a panel of benzophenazine derivatives – unsubstituted benzophenazin-5-ol (VN-13), o-methylated benzophenazin-5-ol (VN-16-3), 4,5-difluorobenzophenazin-5-ol (VN-11), and o-methylated 4,5-difluorobenzophenazin-5-ol (VN-35-3) – was assessed by titration in sterile 96-well plates, followed by plating on solid media. The antimicrobial activity of the compounds was evaluated against pathogens of infectious diseases such as Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Streptococcus agalactiae, Pseudomonas aeruginosa, MRSA (methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant Enterococcus), CRAB (carbapenem-resistant Acinetobacter baumannii), Burkholderia cenocepacia, Candida albicans. The antibacterial and antifungal potential of the compounds was assessed by the presence or absence of microbial colony growth at various concentrations of the benzophenazines (from 2000 μg/ml to 0.016 μg/ml).

Results. The study results demonstrated that all tested benzophenazine derivatives exhibited antibacterial activity against Streptococcus agalactiae and Burkholderia cenocepacia. Against other tested strains, including multidrug-resistant ones, only unsubstituted benzophenazine-5-ol (VN-13) showed activity. Pseudomonas aeruginosa and Escherichia coli ATCC 25922 were resistant to all studied compounds.

Conclusion. Benzophenazine derivatives demonstrate bactericidal or bacteriostatic activity against a number of bacteria, including polyresistant strains, as well as fungi of the genus Candida. Based on the results obtained, it is possible to assume the relevance of further research in the direction of studying the efficacy and safety of benzophenazines as promising antimicrobial agents.

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