Design, synthesis and biological evaluation of novel non-azole derivatives as potential antifungal agents

Practical chemoselective aromatic substitution: the synthesis of N-(4-halo-2-nitrophenyl)benzenesulfonamide through the efficient nitration and halogenation of N-phenylbenzenesulfonamide

A novel route involving the metal-promoted tandem nitration and halogenation of N-phenylbenzenesulfonamide to synthesize N-(4-halo-2-nitrophenyl)benzenesulfonamide derivatives has been developed. The method shows highly practical chemoselective and functional group compatibility. In addition, it employs insensitive and inexpensive Cu(NO3)2·3H2O, Fe(NO3)3·9H2O, and NH4NO3 as the nitration reagents, and it provides a direct approach for the preparation of 4-halo-2-nitroaniline, which is a crucial intermediate for the synthesis of benzimidazoles and quinoxaline derivatives.

Synthesis and Anticandidal Activity of New Imidazole-Chalcones

In the present work, 15 new 1-(4-(1H-imidazol-1-yl)phenyl)-3-(4-substituedphenyl)prop-2-en-1-one derivatives (3a–3o) were synthesized to evaluate their antifungal activity. Structures of newly synthesized imidazole derivatives (3a–3o) were characterized by IR, ¹H-NMR, ¹³C-NMR, and LCMSMS spectroscopic methods. The anticandidal activity of compounds (3a–3o) against C. albicans (ATCC 24433), C. krusei (ATCC 6258), C. parapsilosis (ATCC 22019), and C. glabrata (ATCC 90030) was elucidated according to the EUCAST definitive (EDef 7.1) method. Consistent with the activity studies, 3a–3d were found to be more potent derivatives with their MIC₅₀ values (0.78 µg/mL–3.125 µg/mL) against Candida strains. Compound 3c indicated similar antifungal activity to ketoconazole against all Candida species and was evaluated as the most active derivative in the series. Effects of the most potent derivatives 3a–3d on ergosterol biosynthesis were observed by LC-MS-MS method, which is based on quantification of the ergosterol level in C. krusei. Moreover, these compounds were subjected to a cytotoxicity test for the preliminary toxicological profiles and were found as non-cytotoxic. Furthermore, docking studies for the most active derivative 3c were performed to evaluate its binding modes on lanosterol 14-α-demethylase. In addition to in vitro tests, docking studies also revealed that Compound 3c is a potential ergosterol biosynthesis inhibitor.

Genotoxicity of two new carbazole derivatives with antifungal activity

The class of carbazoles includes compounds with high biological activities and broad spectra of action. PLX01107 and PLX01008 are xenomycins, a new subclass of antimicrobial carbazole derivatives demonstrating strong antifungal activity in vitro. We performed three tests, a bacterial reverse mutation assay (Ames test), in vitro cytokinesis-block micronucleus assay, and chromosome aberration test in mouse bone marrow cells, to investigate the possible genotoxicity of these compounds. Despite their structural similarity, the two compounds had different genotoxicity profiles. PLX01008 showed positive effects in all assays. PLX01107 showed no mutagenicity in the Ames test but demonstrated strong cytogenetic activity in vitro and in vivo. PLX01107 was also tested in the in vivo alkaline comet assay, where a weak but statistically significant increase in DNA damage was seen in liver cells 24h after treatment. Significantly increased levels of formamidopyrimidine DNA glycosylase (FPG)-sensitive sites were found in bone marrow cells of PLX01107-treated mice (FPG-modified comet assay), suggesting induction of oxidative or alkylation damage to DNA.

In vitro antifungal activity of organic compounds derived from amino alcohols against onychomycosis

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.