Electrochemical Sensing of Phenicol Antibiotics at Gold
INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE
Authors: Pilehvar, Sanaz; Dardenne, Freddy; Blust, Ronny; De Wael, Karolien
Phenicols are an effective and a broad spectrum class of antibiotics which has lost favour due to their side effects on human health. A rapid and sensitive electrochemical detection system is developed for the simultaneous detection of chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FF). The electrochemical behaviour of CAP in the presence of its derivatives was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). At a gold electrode, CAP gives rise to a sensitive cathodic peak at -0.68V (versus SCE) in a tris buffer solution (pH 7.6). This behavior gives us the opportunity to introduce a method for sensing CAP electrochemically in the presence of its derivatives. Calibration graphs were linear in the 2.5-7.4 mu mol L-1 concentration range. Deviations from linearity were observed for higher concentrations and this was interpreted to be due to kinetic limitation caused by the saturation of CAP and its reduction products onto the gold electrode surface. A limit of detection of 1 mu mol L-1 was found.
Exploring N-Acylhydrazone Derivatives Against Clinical Resistant Bacterial Strains
Authors: Lannes, Andressa C.; Leal, Bruno; Novais, Juliana S.; Lione, Viviane; Monteiro, Georgia C. T. S.; Lourenco, Andre L.; Sathler, Plinio C.; Jordao, Alessandro K.; Rodrigues, Carlos R.; Cabral, Lucio M.; Cunha, Anna Claudia; Campos, Vinicius; Ferreira, Vitor F.; de Souza, Maria Cecilia B. V.; Santos, Dilvani O.; Castro, Helena C.
Bacterial multiresistance is a health problem worldwide that demands new antimicrobials for treating bacterial-related infections. In this study, we evaluated the antimicrobial activity and the theoretical toxicology profile of N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazide derivatives against gram-positive and gram-negative bacteria clinical strains. On that purpose we determined the minimum inhibitory (MIC) and bactericidal (MBC) concentrations, the in vitro cytotoxicity, and in silico risk profiles, also comparing with antimicrobial agents of clinical use. Among the 16 derivatives analyzed, four nitrofurans (N-H-FUR-NO2, N-Br-FUR-NO2, N-F-FUR-NO2, N-Cl-FUR-NO2) showed promising MIC and MBC values (MIC = MBC = 1-16 mu g/mL). The experimental data revealed the potential of these derivatives, which were comparable to the current antimicrobials with similar bactericidal and bacteriostatic profiles. Therefore, these molecules may be feasible options to be explored for treating infections caused by multiresistant strains. Our in vitro and in silico toxicity reinforced these results as these derivatives presented low cytotoxicity against human macrophages and low theoretical risk profile for irritant and reproductive effects compared to the current antimicrobials (e.g., vancomycin and ciprofloxacin). The molecular modeling analysis also revealed positive values for their theoretical druglikeness and drugscore. The presence of a 5-nitro-2-furfur-2-yl group seems to be essential for the antimicrobial activity, which pointed these acylhydrazone derivatives as promising for designing more potent and safer compounds.