Attempts to Access a Series of Pyrazoles Lead to New Hydrazones with Antifungal Potential Against <em>Candida</em> Species Including Azole-Resistant Strains

Abstract

The treatment of benzylidenemalononitriles 3a-c with phenylhydrazines 4a-n in refluxing ethanol did not provide pyrazole derivatives but furnished hydrazones 1a-o. The structure of hydrazones was secured by X-Ray analysis. Newly synthesized hydrazones 1a-o were tested against 8 Candida spp. strains in a dose response assay to determine the minimum inhibitory concentration (MIC99). Five compounds 1c, 1d, 1i, 1k and 1l were identified as promising antifungal agents against Candida spp. (C. albicans SC5314, C. glabrata, C. tropicalis, C. parapsilosis and C. glabrata (R azoles)) with MIC99 values ranging from 16 to 32 &amp;micro;g/mL. To further evaluate the antifungal potential of the active compounds, they have been assayed against a mammalian cell line HEK293 to determine general cell toxicity and on NCI-60 cancer cell lines panel, demonstrating selectivity antifungal activity over cytotoxicity.