Imidazoles as Serotonin Receptor Modulators for Treatment of Depression: Structural Insights and Structure-Activity Relationship Studies

Design, synthesis and biological evaluation of some imidazo[1,2-a]pyridine derivatives as anti-tubercular agents: an in silico - in vitro approach

In this study, we designed, synthesized and evaluated some novel imidazo[1,2-a]pyridine derivatives as potential anti-TB agents. Preliminary in vitro screening for anti-TB activity of the synthesized compounds was performed against H37Rv strain using the microplate Alamar Blue assay (MABA). Network pharmacology was used to identify the possible targets and pathways of these compounds against Mtb infection. Molecular docking and molecular dynamics simulations were also performed to investigate the binding modes and stability of these compounds with the selected targets. The results showed that some of the synthesized compounds (6b, 6c, 6e, 6f, 6h, 6i, 6j, 6n and 6o) exhibited potent anti-TB activity, with minimum inhibitory concentrations (MICs) ranging from 1.6 to 6.25 μg/mL. The network pharmacology analysis revealed that among the 455 putative targets of imidazo[1,2-a]pyridine derivatives, 24 targets are the potential targets for treatment of Mtb infection. Among these 24 targets, 10 hub-targets were identified (TLR4, ICAM1, TLR9, STAT3, TNFRSF1A, ERBB2, CXCR3, ACE, IKBKG and NOS2) which were significantly involved in GO processes such as positive regulation of DNA-binding transcription factor activity, peptidyl-tyrosine phosphorylation, positive regulation of inflammatory response, mononuclear cell proliferation, regulation of hemopoiesis and cytokine production involved in inflammatory response and KEGG pathways such as pathways in Tuberculosis, NF-kappa B signalling, HIF-1 signalling PD-L1 expression, and PD-1 checkpoint pathway in cancer. Molecular docking and dynamics simulations confirmed the stable interactions of imidazo[1,2-a]pyridine derivatives with core target active sites, highlighting their potential as novel anti-TB drug candidates.

Exploration of oxadiazole clubbed benzhydrylpiperazine pharmacophoric features as structural feature for antidepressant activity: In vitro, in vivo and in silico analysis

Arylpiperazine clubbed various heterocyclic molecules present potential pharmacophoric structural features for the development of psychoactive drugs. There are various CNS active molecules possessing arylpiperazine moiety in their pharmacophore approved by USFDA. In the current study, we have explored the benzhydrylpiperazine moiety clubbed with various substituted oxadiazole moieties (AP1-12) for their monoamine oxidase (MAO) inhibition and antidepressant potential. Compounds AP3 and AP12 exhibited highly potent and selective MAO-A inhibition with IC50 values of 1.34 ± 0.93 µM and 1.13 ± 0.54 µM, respectively, and a selectivity index of 10- and 13-folds, respectively. Both the compounds displayed reversible binding character at the active site of MAO-A. In further in vivo evaluation, both the compounds AP3 and AP12 displayed potential antidepressant-like character in FST and TST studies via significantly reduced immobility time in comparison to non-treated animals. These compounds displayed no cytotoxicity in SH-SY5Y cell lines, which indicates that these compounds are safe for further evaluation. In silico studies reveal that synthesized compounds possess drug-likeness with minimal to no toxicity. In silico studies were conducted to understand the binding interactions and stability of compounds at the binding pocket of enzyme and observed that both the best compounds fit well at the active site of MAO-A lined by amino acid residues Tyr69, Asn181, Phe208, Ile335, Leu337, Phe352, and Tyr444 similar to standard MAO-A inhibitor clorgiline. The molecular dynamic studies demonstrated that AP3 and AP12 formed quite a stable complex at the active site of MAO-A and did not break under small abruption forces. The favourable binding interactions and appropriate ADMET properties present the benzhydrylpiperazine clubbed oxadiazole pharmacophoric features as a potential structural skeleton for further clinical evaluation and development of a new antidepressant drug molecule.