Design, Synthesis, and Antimycobacterial Evaluation of Novel Tetrahydroisoquinoline Hydrazide Analogs.

A series of novel 2-substituted-5,7-dichloro-1,2,3,4-tetrahydroisoquinoline-6-carbohydrazide were designed, synthesized and structures were confirmed by analytical methods, viz., 1 H-NMR, 13 C-NMR and Mass spectrometry. Synthesized derivatives were evaluated for their anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb) H37Ra. Among all the evaluated compounds, 10A25 containing biphenyl moiety exhibited significant inhibition with IC50 4.7 µM. 10A19, with an electron-withdrawing Iodo group in the ortho position of the phenyl exhibited significant anti-tubercular activity with IC50 8.8 µM. IC50 values of the remaining compounds ranged from 9.2 to 73.6 µM. Molecular docking study of the significantly active compound 10A25 was performed to determine the putative binding position of the test ligand at the active site of the selected target proteins Mycobacterium tuberculosis enoyl reductase (InhA) PDB - 4TZK and peptide deformylase PDB - 3E3U. A suitable single crystal for one of the active compounds, 10A12, was generated and analysed to further confirm the structure of the compounds.

Design, Synthesis and Biological Evaluation of Novel Spiro-[Chroman-2,4'-Piperidin]-4-One Analogs as Anti-Tubercular Agents.

A series of novel spiro-[chromane-2,4'-piperidin]-4(3H)-one derivatives were designed, synthesized and structures were confirmed by analytical methods, viz., 1 H-NMR, 13 C-NMR and mass spectrometry. The synthetic derivatives were evaluated for their anti-tuberculosis (anti-TB) activity against Mycobacterium tuberculosis (Mtb) strain H37Ra. Among all the evaluated Compounds, PS08 exhibited significant inhibition with MIC value of 3.72 µM while MIC values of the remaining Compounds ranged from 7.68 to 230.42 µM in comparison to the standard drug INH (MIC 0.09 µM). The two most active Compounds however showed acute cytotoxicity towards the human MRC-5 lung fibroblast cell lines. The in silico ADMET profiles of the titled Compounds were predicted and found within the prescribed limits of the Lipinski and Jorgenson rules. Molecular docking study of the notably active Compound (PS08) was also carried out after performing validation in order to understand the putative binding position of the test ligand at the active site of selected target protein Mtb tyrosine phosphatase (PtpB).