Facile synthesis and biological assays of novel 2,4-disubstituted hydrazinyl-thiazoles analogs

Abstract

A convenient, one-pot multi-component synthesis of new 2,4-disubstituted hydrazinyl-thiazoles was accomplished using different aldehydes/ketones, thiosemicarbazide, and 4-methoxy phenacyl bromide in the presence of a catalytic amount of AcOH in EtOH. Products were obtained in reasonable yields and high purity. The in vitro antioxidant activity of hydrazinyl-thiazoles was evaluated by DPPH radical scavenging activity in comparison to ascorbic acid. Synthesized thiazoles 14c and 14g possessed the lowest IC50 values. Also, hydrazinyl-thiazoles were screened for their in vitro antibacterial activity against six strains of bacteria including S. aureus, M. luteus, E. coli, Ps. aeruginosa, B. subtilis, and A. hydrophila where some products showed good antibacterial activity. Moreover, compound 14a showed anticancer activity against melanoma cancerous cell lines A375 with LC50=0.55 mg/ml, slightly selective versus normal cell lines (Hu-2) with LC50=1.19 mg/ml..

Sequential one‐pot multicomponent synthesis of bis‐aminothiazols and evaluation of their antibacterial and antioxidant activities

“…However, these compounds showed better antibacterial activity against P. aeruginosa and S. aureus than our products because of the presence of the coumarinyl moiety. Moreover, in our recent study, 2,4‐disubstituted hydrazinyl‐thiazoles showed antibacterial activity against S. aureus , M. luteus , E. coli , P. aeruginosa , B. subtilis , and A. hydrophila with the zones of inhibition of 6–11, 7–10, 9–13, 7–17, 6–21, and 6–11 mm, respectively, and these products showed antibacterial activity against E. coli .…”

“…Some proposed radical structures and resonance of radical through the structure of bis‐thiazole 6i are depicted in Scheme . Ultimately, compounds 6a–l, especially 6i–j, can be introduced as potent antioxidant compounds similar to our recently synthesized hydrazinylthiazoles …”

“…Antioxidant activity of bis‐thiazoles was investigated using the DPPH method according to our recent research . DPPH solution (3.9 mL, 6.25 × 10 −5 M in MeOH) was added to bis‐thiazole solution (0.1 mL at different concentrations of 2,000, 1,000, 500, 250, 125, and 62.5 μg/mL in MeOH) and was shaken vigorously.…”

“…Encouraged by all of the above, as well as the limited studies on the synthesis of bis‐thiazoles in the literature, and in continuation of our ongoing research program on the synthesis of mono‐ and bis‐thiazoles and screening for their biological activities, we report in this paper the one‐pot semi‐five‐component, efficient, and rapid method for the synthesis of new bis‐thiazoles and screening otheir antibacterial and antioxidant activities.…”

Antimicrobial activities of thiazole, imidazolidine, tetrahydropyrimidine derivatives and silver/polyvinyl alcohol nanocomposites against selected zoonotic fish bacterial pathogens

“…This functional group is present in prothinoamide antimycobacterial drug (Bartels and Bartels, 1998). Thiazole ring itself is a biologically active component and recently synthesised 2, 4-disubstituted hydrazinyl-thiazoles have been introduced as antibacterial, antioxidant and anticancer agents (Ghanbari Pirbasti and Mahmoodi, 2016). The best result in antibiogram test was observed with penicillin antibiotic against S. İniae with MIC value of 0.5 µg ml -1 .…”