Antimicrobial activity of some novel 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives

Abstract

Background Infectious diseases, especially those caused by multidrug-resistant bacteria, are becoming a serious problem worldwide because of the lack of effective therapeutic agents. Moreover, most antifungal drugs exhibit low efficacy and high toxicity because of the similarity between fungal and human cells. These issues warrant the search for potential new agents. Objectives To synthesize potent 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives, improve the synthetic process, elucidate their structures, and determine their antimicrobial activity. Methods 2-Iodoaniline was used as an initial reactant in a 3-step process for the synthesis of 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives, including an acylation reaction, a cyclization reaction, and aldol condensation reactions. The structures of the obtained derivatives were investigated and elucidated using spectral methods. Antimicrobial activity toward 5 bacterial strains and 2 fungal strains was determined using Kirby–Bauer and agar dilution methods. Results We successfully synthesized 12 novel compounds and elucidated their structures. The derivatives had no antifungal activities. By contrast, they showed remarkable antibacterial activities. Some of them with minimum inhibitory concentrations (MICs) ≤8 μg/mL in both Staphylococcus aureus and methicillin-resistant S. aureus. Conclusions A simple and flexible way to synthesize new compounds with a thiazolidin-4-one ring was determined. Some of these new compounds have outstanding effects with low MICs for bacteria. Their further investigation as therapeutic agents is warranted.

Antibacterial hydrogel containing Piper Betel L. extract for acne treatment, an ex vivo investigation

“…Interestingly, the product effects on the standard bacterial strains were much higher than the acne-sample isolated ones. This is due to the fact that bacteria in acne samples have gained antibacterial resistant property (i.e., less sensitive to the antibacterial agents) as a results of irrational uses of antibiotics in Vietnam [40][41] . Lastly, the fact that the hydrogels possessed better antibacterial effects than the positive controls (vancomycin and colistin for gram-positive and gram-negative bacteria, respectively) might, again, be explained by the resistance of the tested bacteria against these commercial drugs.…”