Preliminary antifungal activity assay of selected chlorine-containing derivatives of xanthone and phenoxyethyl amines

The aim of this study was to evaluate antifungal activity in a diverse group of chlorine-containing xanthone and phenoxyethyl amine derivatives - and to select the most promising compounds for further studies. The antifungal efficacy of 16 compounds was tested with qualitative and quantitative methods against both reference and clinical strains of dermatophytes, moulds and yeasts. The disc-diffusion method has demonstrated that from 16 tested compounds, 7 possess good antifungal activity against dermatophytes and/or moulds while none of them has shown good efficacy against yeasts or bacterial strains. The most active compounds (2, 4, 10, 11, 12, 15, 16) were tested quantitatively by broth dilution method to obtain MIC values. The MIC values against dermatophytes ranged from 8 to 64 μg/ml. Compound 2 was the most active one against dermatophytes (MIC 50 and MIC 90 were 8 μg/ml). The MIC values for moulds ranged from 16 to 256 μg/ml. Compound 4 was the most active one against moulds, with MIC 50 and MIC 90 values amounting to 32 μg/ml. Among the tested compounds, compound 4 (derivative of xanthone) was the most active one and expressed good antifungal efficacy against clinical strains of dermatophytes and moulds. However, another xanthone derivative (compound 2) was the most active and selective against dermatophytes.