Evaluation of antifugal activity of xanthone derivatives against selected dermatophytes Ocena aktywno ci przeciwgrzybiczej wybranych pochodnych ksantonu wobec dermatofitów

Introduction: Fungal infections of different etiologies are now a global problem. Increase in the incidence of dermatophytosis is associated with climate change, the dynamic progress of civilization and the change in lifestyle. The continuously increasing number of fungal infections in recent decades has led to significant progress in their treatment. However, increasing resistance to chemotherapeutic agents is the cause of failures in the treatment of fungal infections. The solution is to search for new substances with antifungal activity. Natural derivatives of xanthone and the possibility of their chemical modification are becoming more popular. Aim of the study: Evaluation of in vitro antifungal activity of synthetic xanthone derivatives against selected species of dermatophytes. Materials and methods: A total of 32 xanthone derivatives produced by chemical synthesis were tested. Antifungal activity against 8 species of dermatophytes was tested by disc diffusion method on Sabouraud agar and then the MIC (μg/ml) of the most active compounds was evaluated by broth dilution method with RPMI 1640 medium. The method recommended by NCCLS was used in the study (M38-A). Results: 5 of tested xanthone derivatives showed the highest activity in disc-diffusion method, giving 20-40 mm of inhibition zones of dermatophytes. 3 compounds were selected to evaluate by broth dilution method with RPMI 1640 medium. The range of their MICs was 8-32 μg /ml. Conclusions: The high antifungal activity of selected xanthone derivatives against dermatophytes gives the opportunity to develop further studies and chemical modifications in the studied group of compounds.