A Study of Fluorinated β-Nitrostyrenes as Antimicrobial Agents

Abstract

Abstract:The effect of variously fluorine-substituted β-methyl-β-nitrostyrenes on their antimicrobial activity was investigated. Their efficacy was determined by minimum inhibition concentration (MIC) in cultures of Gram positive and Gram negative bacteria and a fungus. Highest activity against the Gram negative bacterium, E.coli, was achieved with 4-fluorine-aryl substituted β-methyl-β-nitrostyrenes, while most compounds gave excellent results against gram positive bacteria. Importantly, the addition of the β-methyl group profoundly enhanced the antibacterial activity of the compounds tested. The comparative K D values for the most potent compounds against E.coli were much lower than those required for the gram positive and fungus counterparts. This investigation illustrated that fluorine substituted nitropropenylarenes have enhanced antimicrobial activity suitable for antibiotic applications.

Comparisons of Halogenated β-Nitrostyrenes as Antimicrobial Agents

“…This compound has been evaluated in different assays, and the results in Table 3 are from an assay in which I was evaluated against 4-fluoro-β-nitrostyrene (without the β-methyl group), which showed that I was much better than 4-fluoro-β-nitrostyrene and also A-1. In all of our work, we have found this to be the case (see [12,13]). Table 1 shows the MICs in μg mL −1 of β-nitrostyrene analogues tested against four strains of bacteria and a fungus.…”

“…Three assays, as previously described [12,13], were used to determine the antibacterial efficacy of the β-nitrostyrenes by their activity against a panel of 4 bacteria and a fungus (Candida albicans). The results appear as the minimum inhibitory concentration (MIC) for each compound and are presented in the Tables 1 and 2 The three assays were performed as follows: Assay 1.…”

“…Reactions were monitored by thin layer chromatography using Merck 60 F 254 silica gel plates in (3:1) isopropanol-H 2 O eluting solvent. All of the prepared compounds were found to be E-β-nitrostyrenes from NMR data and were also characterized by MS analysis, as previously described [12]. The compounds shown in Figure 1 were prepared according to published methods [12] and are briefly described here.…”

“…Our previous research on the structure activity relationships (SARs) of nitrostyrene derivatives for antibacterial activity revealed that the presence of a fluorine atom at the para position on the benzene ring showed the highest activity against Gram-negative bacteria [12,13]. The aim of the present research work is to study the effect of various halogen substitutions at different ring and side chain positions of β-nitrostyrene derivatives on antibacterial activity.…”

Evaluation of Photodynamic Inactivation Efficiency Using Conventional and Decorative Light-Emitting Diode Lamps

“…(11,12) This approach does not require medication, and hence, does not generate drug resistance. (13)(14)(15)(16) Because this sterilization method is effective for treating antibiotic-resistant strains, it has been receiving increasing attention. (17,18) PDI uses a specific-wavelength LED or laser irradiation on a photosensitizer (PS).…”