ABSTRACT
The discovery and development of isoform-selective histone deacetylase (HDAC) inhibitor is a challenging task because of the sequence homology among HDAC enzymes. In the present work, novel tetrahydro benzo[b]thiophene-3-carbonitrile based benzamides were designed, synthesized, and evaluated as HDAC inhibitors. Pharmacophore modeling was our main design strategy, and two novel series of tetrahydro benzo[b]thiophene-3-carbonitrile derivatives with piperidine linker (series 1) and piperazine linker (series 2) were identified as HDAC inhibitors. Among all the synthesised compounds, 9h with 4-(aminomethyl) piperidine linker and 14n with piperazine linker demonstrated good activity against human HDAC1 and HDAC6, respectively. Both the compounds also exhibited good antiproliferative activity against several human cancer cell lines. Both these compounds (9h and 14n) also induced cell cycle arrest and apoptosis in U937 and MDA-MB-231 cancer cells. Overall, for the first time, this research discovered potent isoform-selective HDAC inhibitors using cyclic linker instead of the aliphatic chain and aromatic ring system, which were reported in known HDAC inhibitors.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Discovery , Histone Deacetylase Inhibitors/pharmacology , Thiophenes/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/chemistry , Histone Deacetylases , Humans , Molecular Structure , Structure-Activity Relationship , Thiophenes/chemical synthesis , Thiophenes/chemistryABSTRACT
Tuberculosis (TB) is one of the world's deadliest infectious diseases, caused by Mycobacterium tuberculosis (Mtb). In the present study, a 3D QSAR study was performed for the design of novel substituted benzimidazole derivatives as anti-mycobacterial agents. The anti-tubercular activity of the designed compounds was predicted using the generated 3D QSAR models. The designed compounds which showed better activity were synthesized as 1,2-disubstituted benzimidazole-5-carboxylic acid derivatives (series 1) and 3-substituted-5H-benzimidazo[1,2-d][1,4]benzodiazepin-6(7H)-one derivatives (series 2) using the liquid phase combinatorial approach using a soluble polymer assisted support (PEG5000). The compounds were characterized by 1H-NMR, 13C-NMR, FTIR and mass spectrometry. HPLC analysis was carried out to evaluate the purity of the compounds. We observed that the synthesised compounds inhibited the growth of intracellular M. tuberculosis H37Rv in a bactericidal manner. The most active compound 16 displayed an MIC value of 0.0975 µM against the Mtb H37Rv strain in liquid cultures. The lead compound was also able to inhibit the growth of intracellular mycobacteria in THP-1 macrophages.
ABSTRACT
The synthesis of 1,2,5-trisubstituted benzimidazole derivatives was carried out using liquid phase combinatorial approach using soluble polymer assisted support (PEG5000). Synthesised compounds were characterised by FTIR, ESI-MS, 1H NMR and 13C NMR. The purity of compounds was confirmed with HPLC analysis. Compounds were also docked into the binding site of human dihydroorotate dehydrogenase (hDHODH). The synthesised compounds were screened for hDHODH enzyme inhibition assay using brequinar as standard compound. The synthesised compounds demonstrated comparative biological activity. Synthesised compounds 8d and 8e demonstrated IC50 value of 81±2nM and 97±2nM, respectively.
