Microwave-assisted synthesis, molecular docking and antitubercular activity of 1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives.

Based on bioisosteric similarities with isoniazid, a series of 1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives has been designed. The target compounds have been synthesized by multicomponent reaction which involves one-pot organic reactions using ethylcyanoacetate, urea/thiourea and arylaldehydes in presence of ethanolic K(2)CO(3). Two methodologies, conventional and microwave-assisted, have been adopted for the synthesis. The later strategy gave high yields in less than 10 min as compared to long hours using the former approach. Molecular docking of the target compounds into the enzyme Mycobacterium tuberculosis enoyl reductase (InhA) revealed important structural information on the plausible binding interactions. Major binding interactions were found to be of dispersion type (residues Tyr158, Ile215, Met103 and Met199) and a hydrogen bond with Tyr158. Binding poses of the all the compounds were energetically favorable and showed good interactions with the active site residues. Few selected compounds were also evaluated for antitubercular activity in vitro against drug-sensitive M. tuberculosis H37Rv strain and clinically isolated S, H, R and E resistant M. tuberculosis by luciferase reporter phage (LRP) assay method. Some compounds displayed promising antimycobacterial activity comparable or less than the standard drugs isoniazid and rifampicin.

Synthesis of quinoline coupled [1,2,3]-triazoles as a promising class of anti-tuberculosis agents.

A series of quinoline coupled 1,2,3-triazoles compounds have been synthesized by 'click chemistry' from azidomethyl quinoline with different alkynes. The efficiency and fidelity of the Cu(I)-catalyzed azide-alkyne reaction are substantiated by good yields and exclusive formation of the expected 1,4-disubstituted triazole product. All the synthesized compounds were screened for anti-tubercular activity against Mycobacterium tuberculosis H37Rv by luciferase reporter phage (LRP) assay. Quinoline coupled triazole sugar hybrid, 20 is the most potent compound in the series with 76.41% and 78.37% reduction calculated based on percentage reduction in Relative Light Units at 5 and 25 µg/mL, respectively.