In vitro evaluation of antifungal properties of phenylpropanoids and related compounds acting against dermatophytes.

Thirty-four arylpropanoids and related compounds were evaluated in vitro for antifungal properties. Among them, 22 phenyl-, 4 naphthyl-, and 4 phenanthrylpropanoids; naphthalene; phenanthrene; and 2-chloro-1-hexyl-1-propanone were tested against dermatophytes by the agar dilution method. alpha-Halopropiophenones exhibited a broad spectrum of activities against Microsporum canis, Microsporum gypseum, Trichophyton mentagrophytes, Trichophyton rubrum, and Epidermophyton floccosum, with MIC values between 0.5 and >50 microg/mL. Keto, alcohol, and alpha-haloketo propyl derivatives of naphthalene and phenanthrene also showed very good activity against all dermatophytes tested, clearly showing that in these series, a halogen atom is not necessary for activity. Phenanthryl derivatives were more active (MICs, 3-20 microg/mL) than naphthyl ones (MICs, 3-50 microg/mL). A structure-activity relationship study was carried out and aided in establishing the structural requirements of arylpropanoids for antifungal activities. Because dermatophytes are a group of fungi that characteristically infect the keratinized areas of the body, these new series of antifungal compounds open the possibility of discovering new topical antifungal drugs for the treatment of dermatomycoses, which are frequently very difficult to eradicate.

In vitro antifungal evaluation and studies on the mode of action of xanthoxyline derivatives.

This study describes the fungistatic effect of xanthoxyline (CAS 90-24-4) and its derivatives against a panel of yeasts, filamentous fungi and dermatophytes, by using the agar dilution method. Results indicated that simple structural modifications led to more potent derivatives, especially in relation with dermatophytes. The most active compound tested (10), which is a benzenesulphonyl derivative, was 12-fold more potent than xanthoxyline itself against Trichophyton rubrum. The evaluation of the mode of action with the whole cell Neurospora crassa assay, suggested that some selected compounds may be acting by the inhibition of fungal cell-wall polymers synthesis or assembly.