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Environmental Pollution (Barking, Essex... Sep 2019Increasing attention has been attracted in developing new technologies to remove chlorofene (CF) and dichlorofene (DCF), which were active agents in antimicrobials for...
Increasing attention has been attracted in developing new technologies to remove chlorofene (CF) and dichlorofene (DCF), which were active agents in antimicrobials for general cleaning and disinfecting. This study investigated the significant influences of bicarbonate (HCO) on the degradation of CF and DCF in the Cu(II)-mediated Fenton-like system Cu/HO. Our results indicate that HCO may play a dual role to act 1) as a ligand to stabilize Cu(II), forming soluble [Cu(HCO)(S)] species to catalyze HO producing hydroxyl radical (OH) and superoxide ion (O) and 2) as a OH scavenger. Furthermore, the reaction kinetics, mechanisms, and intermediates of CF and DCF were assessed. The apparent rate constants of CF and DCF were enhanced by a factor of 8.5 and 5.5, respectively, in the presence of HCO at the optimized concentration of 4 mM. Based on the intermediate identification and frontier electron densities (FEDs) calculations, the associated reaction pathways were tentatively proposed, including C-C scission, single or multiple hydroxylation, and coupling reaction. In addition, significant reduction in the aquatic toxicity of CF and DCF was observed after treatment with Cu/HO-HCO system, evaluated by Ecological Structure Activity Relationships (ECOSAR) program. These findings provide new insights into Cu(II)-mediated reactions to better understand the environmental fate of organic contaminants in carbonate-rich waters.
Topics: Anti-Bacterial Agents; Bicarbonates; Carbonates; Chlorophenols; Copper; Dichlorophen; Disinfectants; Environmental Restoration and Remediation; Hydrocarbons, Halogenated; Hydrogen Peroxide; Hydroxyl Radical; Iron; Kinetics; Oxidation-Reduction; Phenol
PubMed: 31227352
DOI: 10.1016/j.envpol.2019.05.148 -
Chemical Biology & Drug Design Aug 2019The need for new antibacterial agents is increasingly becoming of great importance as bacterial resistance to current drugs is quickly spreading. Enoyl-acyl carrier...
The need for new antibacterial agents is increasingly becoming of great importance as bacterial resistance to current drugs is quickly spreading. Enoyl-acyl carrier protein reductases (FabI) are important enzymes for fatty acid biosynthesis in bacteria and other micro-organisms. In this project, we conducted structure-based virtual screening against the FabI enzyme, and accordingly, 37 compounds were selected for experimental testing. Interestingly, five compounds were able to demonstrate antimicrobial effect with variable inhibition activity against various strains of bacteria and fungi. Minimum inhibitory concentrations of the active compounds were determined and showed to be in low to medium micromolar range. Subsequently, enzyme inhibition assay was carried out for our five antimicrobial hits to confirm their biological target and determine their IC values. Three of these tested compounds exhibited inhibition activity for the FabI enzyme where our best hit MN02 had an IC value of 7.8 μM. Furthermore, MN02 is a small bisphenolic compound that is predicted to have all required features to firmly bind with the target enzyme. To sum up, hits discovered in this work can act as a good starting point for the future development of new and potent antimicrobial agents.
Topics: Anti-Bacterial Agents; Bacteria; Bacterial Proteins; Drug Design; Enoyl-(Acyl-Carrier-Protein) Reductase (NADH); Enzyme Inhibitors
PubMed: 31063658
DOI: 10.1111/cbdd.13536