Fatty acid methyl esters (FAMEs) were obtained from vegetable oils of soybean, corn and sunflower. The current study was focused on evaluating the antifungal activity of FAMEs mainly against Paracoccidioides spp., as well as testing the interaction of these compounds with commercial antifungal drugs and also their antioxidant potential. FAMEs presented small IC50 values (1.86-9.42 μg/mL). All three FAMEs tested showed antifungal activity against isolates of Paracoccidioides spp. with MIC values ranging from 15.6-500 µg/mL. Sunflower FAMEs exhibited antifungal activity that extended also to other genera, with an MIC of 15.6 μg/mL against Candida glabrata and C. krusei and 31.2 μg/mL against C. parapsilosis. FAMEs exhibited a synergetic effect with itraconazole. The antifungal activity of the FAMEs against isolates of Paracoccidioides spp. is likely due to the presence of methyl linoleate, the major compound present in all three FAMEs. The results obtained indicate the potential of FAMEs as sources for antifungal and antioxidant activity.
The aim of this study was to isolate and identify the antifungal compounds from the extracts of Schinus terebinthifolius (Anacardiaceae) against clinical isolates of the pathogenic fungus Paracoccidioides brasiliensis.
Iron plays a crucial role in various biological processes, including enzyme function, DNA replication, energy production, oxygen transport, lipid, and carbon metabolism. Although it is abundant in the Earth’s crust, its bioavailability is restricted by the insolubility of ferric iron (Fe³ + ) and the auto-oxidation of ferrous iron (Fe² + ) in oxygen-rich environments. This limitation poses significant challenges for all organisms, including fungi, which have developed intricate mechanisms for iron acquisition and utilization. These mechanisms include reductive iron uptake, siderophore production/transport, and heme utilization. Fungi employ a variety of enzymes—such as ferric reductases, ferroxidases, permeases, and transporters—to regulate intracellular iron levels effectively. The challenge is heightened for pathogenic fungi during infection, as they must compete with the host’s iron-binding proteins like transferrin and lactoferrin, which sequester iron to restrict pathogen growth. This review delves into the iron acquisition strategies of medically important fungi, emphasizing the roles of reductive iron uptake and siderophore pathways. Understanding these mechanisms is vital for enhancing our knowledge of fungal pathogenesis and developing effective treatments. By targeting these iron acquisition processes, new antifungal therapies can be formulated more effectively to combat fungal infections.
Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.
1 September 2015 in European Journal of Medicinal Chemistry