Synthesis and Evaluation of Pyridinyltriazoles as Inhibitors of p38 MAP Kinase

Objective(s):Inhibitors of p38 MAP kinase are considered as suitable target in the treatment of inflammatory diseases such as rheumatoid arthritis and bowel inflammatory diseases. The development of 5-alkylthio-1-aryl-2-(4-pyridinyl) triazoles as inhibitors of p38 MAP kinase is described. These are analogues of 4- pyridinyl imidazole p38 MAP kinase inhibitor reported by Merck Research Laboratories, in which imidazole ring has been replaced with triazole. Materials and Methods:Reaction of pyridine-4-carboxylic acid hydrazide 1 and arylisothiocyanate (2a, b) gave the intermediate thiourea derivative 3a, b (Figure 2). Refluxing of the latter in aqueous saturated sodium carbonate gave 1-aryl-5-mercapto-2-(4-pyridinyl) triazoles 4a, b. Treatment of 4a, b with alkyl iodide afforded the desired 5-alkylthio-1-aryl-2-(4-pyridinyl) triazoles (5a-d). P38 MAP kinase inhibitory activity of the synthesized compounds was evaluated in vitro by ELISA method and also by molecular docking. Results:Compound 5c at 1 µM concentration and compound 5d at 1 µM and 10 µM significantly inhibited the p38 phosphorylation. These inhibitory effects are equal to those of standard compound SB202190 and no significant differences were observed. Conclusion:We demonstrated that both tested compounds have inhibitory effect on p38 MAP kinase and we did not find significant difference between their inhibitory effects and those of standard inhibitor SB202190.