RESUMO
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..
Assuntos
Tiazóis/síntese química , Tiazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/síntese química , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Linhagem Celular Tumoral , Técnicas de Química Sintética , Humanos , Concentração Inibidora 50 , Tiazóis/químicaRESUMO
New 5-aryl-10-(4-(4-methoxyphenyl)thiazole-2-yl)-9,10-dihydropyrido[2,3-d:5,6-d']dipyrimidinone-2,4,6,8-(1H,3H,5H,7H)-tetraones 6a-d were synthesized through one-pot four-component reaction of aldehydes, barbituric acid, and thiazole using Zn(2+) @KSF under reflux condition. The key features of this reaction are: incorporating four heterocyclic rings, using a heterogeneous and efficient catalyst, high yield, and easy-to-setup reaction. The structure of the products was confirmed by FT-IR, (1)H NMR, and (13)C NMR spectra. The antibacterial activities of compounds 6a-d were screened against Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, and Staphylococcus aureus bacterial strains using the zone inhibition method. Also, the 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of compounds 6a-d were evaluated. All compounds showed good antioxidant capacity in comparison to ascorbic acid. The IC50 values of the antioxidant activity were calculated. The proposed mechanism for antioxidant activity is discussed.
