Antifungal Activity and Studies on Mode of Action of Novel Xanthoxyline‐Derived Chalcones

Abstract

Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2'-OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3-(2-chlorophenyl)-1-(2'-hydroxy-4',6'-dimethoxyphenyl)prop-2-en-1-one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC = 12.5 microg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC(50)] and 90 % [MIC(90)] of the isolates were inhibited = 12.5 and 25 microg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of x 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy-chalcones.

Phytochemicals fromKaempferia angustifoliaRosc. and Their Cytotoxic and Antimicrobial Activities

“…Compounds ( 4 ) and ( 6 ) were not tested towards C. albicans and fungi due to insufficient amount of samples. The antifungal properties of flavokawain A ( 4 ) against Saccharomyces cerevisiae , Candida albicans, and some other fungi were reported to be inactive [24], and these results complement our findings. Compound 4 did not show any inhibition towards Gram-positive and Gram-negative bacteria tested in this study.…”

Synthesis of 4′‐Hydroxy‐3′‐piperidinomethylchalcone Derivatives and Their Cytotoxicity Against PC‐3 Cell Lines

“…The molar ratios of reactants (paraformaldehyde, piperidine, and chalcone) along with the physical data of the compounds 2a-e are presented in the Table 2. The 1 H-NMR, 13 C-NMR, UV, and IR spectra of the compounds 2a -e were in accordance with their chemical structures (Tables 3 and 4). Elemental analyses results (C, H, N) were within 0.4% of the calculated values.…”

“…Chalcones are a,b-unsaturated ketones, and they are associated with diverse biological activities. Recently, 4-hydroxychalcones have demonstrated their effectiveness as cytotoxic [8,9], antitumor [10,11] antioxidative [10], antibacterial [12], antifungal [13], antileishmanial [14], and antinociceptive [15] agents. Antimicrobial [16] and mosquito repellent [17] activities of orthoaminomethyl phenol derivatives (Mannich phenols) are also noteworthy.…”

Antifungal activity of 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone against Candida albicans: evidence for the antifungal mode of action

“…CAS against C. albicans ATCC 10231 could be attributed to the fact that FLU action is directed to ergosterol biosynthetic pathway, CAS inhibits cell wall b-glucan synthesis, and 4HMBA inhibits cell transition between yeast-form (non virulent) to filamentous-form (virulent). Boeck et al (2005) have reported hydroxyl chalcones (structurally related to hydroxyl acetophenones) with inhibitory activity on fungal cell wall assembly. Our findings suggest 4HMBA could have an inhibitory effect on the C. albicans cell wall, but the synergistic combination showed by 4HMBA ?…”