Browsing by Author "Kalra, S."

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Anticancer activity of dihydropyrazolo[1,5-c]quinazolines against rat C6 glioma cells via inhibition of topoisomerase II
(Wiley-VCH Verlag, 2018) Kaur, G.; Cholia, R.P.; Joshi, G.; Amrutkar, S.M.; Kalra, S.; Mantha, Anil K.; Banerjee, U.C.; Kumar, Raj
The design and synthesis of dihydropyrazolo[1,5-c]quinazolines (1a?h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling. ? 2018 Deutsche Pharmazeutische Gesellschaft
In silico binding mechanism prediction of benzimidazole based corticotropin releasing factor-1 receptor antagonists by quantitative structure activity relationship, molecular docking and pharmacokinetic parameters calculation
(Taylor and Francis Ltd., 2018) Kumar, N.; Mishra, S.S.; Sharma, C.S.; Singh, H.P.; Kalra, S.
Despite the various research efforts toward the treatment of stress-related disorders, the drug has not yet launched last 20?years. Corticotropin releasing factor-1 receptor antagonists have been point of great interest in stress-related disorders. In the present study, we have selected benzazole scaffold-based compounds as corticotropin releasing factor-1 antagonists and performed 2D and 3D QSAR studies to identify the structural features to elucidating the binding mechanism prediction. The best 2D QSAR model was obtained through multiple linear regression method with r2 value of.7390, q2 value of.5136 and pred_r2 (predicted square correlation coefficient) value of.88. The contribution of 2D descriptor, T_2_C_1 was 60% (negative contribution) and 4pathClusterCount was 40.24% (positive contribution) in enhancing the activity. Also 3D QSAR model was statistically significant with q2 value of.9419 and q2_se (standard error of internal validation) value of.19. Statistical parameters results prove the robustness and significance of both models. Further, molecular docking and pharmacokinetic analysis was performed to explore the scope of investigation. Docking results revealed that the all benzazole compounds show hydrogen bonding with residue Asn283 and having same hydrophobic pocket (Phe286, Leu213, Ile290, Leu287, Phe207, Arg165, Leu323, Tyr327, Phe284, and Met206). Compound B14 has higher activity compare to reference molecules. Most of the compounds were found within acceptable range for pharmacokinetic parameters. This work provides the extremely useful leads for structural substituents essential for benzimidazole moiety to exhibit antagonistic activity against corticotropin releasing factor-1 receptors. ? 2017 Informa UK Limited, trading as Taylor & Francis Group.
Interaction between topoisomerases and histone deacetylases: Role in cancer progression and therapeutic interventions
(Nova Science Publishers, Inc., 2017) Joshi, G.; Thakur, A.; Kaur, G.; Kalra, S.; Singh, S.; Kumar, R.
DNA topoisomerases are termed as the magicians of the DNA world, as they are involved in overcoming all the topological DNA problems. Histone Deacetylases are the collection of enzymes that assist in the regulation of DNA control. The overexpression of topoisomerases and histone deacetylases are found in various diseases including cancer. Till date, many therapies have been discovered to target topoisomerases and histone deacetylases individually. However, most of these treatments are associated with the toxicities and drug resistance. The drug resistance apart from known mechanism(s) could occur due to crosstalk(s) of topoisomerases with various proteins associated directly or indirectly with the cancer prognosis. Histone deacetylases that render topoisomerase inhibitors resistant also insensitize them toward binding to the receptor. The chapter overlays the discussion on the underlying mechanism(s) involved in topoisomerase and histone deacetylases interactions. The chapter also congregates the information suggested for the essential pharmacophore development for such hybrid drug discovery. The attempt has also been made to give a preliminary virtual background on the fundamental interaction of these two proteins along with the primary amino acids involved in such interaction. ? 2017 Nova Science Publishers, Inc.