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Dermatomycoses are infections caused by fungi and yeasts and the drug treatment is considered expensive and extensive. Researchers are synthesizing new organic compounds in order to obtain more effective molecules that provide reduced adverse effects. Our research group has synthesized and evaluated the biological activities of aminoalcohol and diamine derivatives, which were considered active against human pathogenic fungi. Therefore, the objective of this study was to evaluate the in vitro antifungal activity of aminoalcohols and diamine derivatives against fungi and yeasts that cause dermatomycoses. The minimum inhibitory concentrations (MICs) and the minimum fungicidal concentration (MFC) of aminoalcohol (1–4) and diamine (5–13) derivatives was determined against Trichophyton mentagrophytes, T. rubrum, Epidermophyton floccosum, and Candida albicans according to protocols from the Clinical and Laboratory Standards Institute. All molecules exhibited fungicidal activity against the evaluated fungal strains, with the MIC and MFC ranging between 0.12 and 1000 μg/mL for filamentous fungi and 0.6 and 1250 μg/mL for yeasts. The best activity was attributed to diamines compared to aminoalcohols, with an emphasis on molecules 6 and 7. These results demonstrate the antifungal potential of the evaluated aminoalcohols and diamines against the four primary fungal species that cause dermatomycoses.

Infections caused by microorganisms of the Candida genus represent a major cause of morbidity and mortality among the population. Therefore, this study aimed at evaluating the antifungal activity and toxicity of resveratrol-analog Schiff bases. Faced with Candida albicans ATCC 10,231, the broth microdilution method was used, along with amphotericin B as the reference drug. The toxicity was evaluated in human keratinocyte cells and against Artemia salina. All analogs were active against the microorganism and caused structural changes in the yeast. The minimum inhibitory concentration was lower for analog A (156.3 µg mL−1), followed by B (312.5 µg mL−1), C (312.5 µg mL−1) and D (625 µg mL−1); while the minimum fungicidal concentration was lower for A (1,250 µg mL−1), B (1,250 µg mL−1) and D (1,250 µg mL−1), followed by C (2,500 µg mL−1). In keratinocytes, the compounds presented cell viability between 50.9 and 93%. Against A. salina, the compounds presented moderate cytotoxic activity. The compound with the nitro group, an electron withdrawing group, in the para position presented better antifungal activity. Resveratrol analogs can be promising in the development of new antifungal agents. Keywords: Resveratrol analogs, Schiff bases, Candida albicans, Antifungal activity, Toxicity

Onychomycosis is a fungal infection of the nail caused by high densities of filamentous fungi and yeasts. Treatment for this illness is long-term, and recurrences are frequently detected. This study evaluated in vitro antifungal activities of 12 organic compounds derived from amino alcohols against standard fungal strains, such as Trichophyton rubrum CCT 5507 URM 1666, Trichophyton mentagrophytes ATCC 11481, and Candida albicans ATCC 10231. The antifungal compounds were synthesized from p-hydroxybenzaldehyde (4a-4f) and p-hydroxybenzoic acid (9a-9f). Minimum inhibitory concentrations and minimum fungicidal concentrations were determined according to Clinical and Laboratory Standards Institute protocols M38-A2, M27-A3, and M27-S4. The amine series 4b-4e, mainly 4c and 4e compounds, were effective against filamentous fungi and yeast (MIC from 7.8 to 312 µg/mL). On the other hand, the amide series (9a-9f) did not present inhibitory effect against fungi, except amide 9c, which demonstrated activity only against C. albicans. This allowed us to infer that the presence of amine group and intermediate carbon number (8C-11C) in its aliphatic side chain seems to be important for antifungal activity. Although these compounds present cytotoxic activity on macrophages J774, our results suggest that these aromatic compounds might constitute potential as leader molecules in the development of more effective and less toxic analogs that could have considerable implications for future therapies of onychomycosis.