School Of Basic And Applied Sciences
Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/17
Browse
13 results
Search Results
Item Design, Synthesis and Evaluation of Donepezil-Rasagiline Based Compounds as Multipotent Inhibitors for the Treatment of Alzheimer’s Disease(Central University of Punjab, 2019) Kumar, Bhupinder; Kumar, VinodAlzheimer’s disease (AD) is multifactorial in nature and different enzymes including MAO, AChE, and amyloid beta are implicated in its pathogenesis. The pathomechanism of AD is complex in nature and single target drugs proved to be ineffective for the treatment of the disease. With an aim of developing dual/multipotent inhibitors, 4,6- diphenylpyrimidines were optionally substituted with propargyl group and an ethyl chain containing a cyclic or acyclic tertiary nitrogen atom (piperidine/morpholine/pyrrolidine/N,N-dimethyl) as potential pharmacophores for MAO and AChE enzymes. Compound VB1 was found to be the most potent MAO-A (IC50 value of 18.34 ± 0.38 nM) inhibitor and VB8 was found to be the most potent AChE (IC50 value of 9.54 ± 0.07 nM) inhibitor. Compound VB3 was another promising compound in series-I with IC50 values of 28.33 ± 3.22 nM and 18.92 ± 0.29 nM against MAO-A and AChE, respectively and displayed very high selectivity index (103) for AChE over BuChE. These compounds were found to be reversible inhibitors of MAO and AChE enzymes and non-toxic to the human neuroblastoma SH-SY5Y cells. Based on structure-activity relationship analysis of the first series of compounds, second series of the compounds were designed by fixing the position of piperidine/morpholine ethyl chain at the para position of one of the phenyl rings. In the second series, compound VP15 v was found to be a multi-potent inhibitor of MAO-B and AChE with IC50 values of 0.37 ± 0.03 μM and 0.04 ± 0.003 μM, respectively. VP15 was found to be selective for MAOB with selectivity index of 270 over MAO-A. It also displayed SI of 625 for AChE over BuChE. VP15 was found to be irreversible inhibitor of MAO-B. In the third series of target compounds, both the phenyl rings of diphenylpyrimidines were substituted with O-propargyl groups. Different derivatives have been synthesized with O-propargyl groups substituted at ortho, meta and para positions of the phenyl rings. In the third series of compounds, AVB1 and AVB4 were found to be the most potent inhibitors of AChE and MAO-B with IC50 values of 1.35 ±0.03 μM and 1.49 ± 0.09 μM, respectively. In the reversible inhibition studies, the lead compounds were found to be reversible inhibitors of MAO-B and AChE enzymes. In the ROS protection inhibition studies, AVB1 and AVB4 displayed good activity in SH-SY5Y cells and AVB1 reduced the ROS levels up to 30% at 5 μM. This series of compounds were also found to be non-toxic to the SH-SY5Y cells in the cytotoxicity studies. Thus, from the present study it can be concluded that 4,6-diphenylpyrimidine derivatives can act as potential lead for the development of effective drug candidates for the treatment of AD. Compound VB3 and VP15 were found to be the most potent dual inhibitors of MAO and AChE.Item Dipropargyl substituted diphenylpyrimidines as dual inhibitors of monoamine oxidase and acetylcholinesterase(Elsevier, 2019) Kumar, Bhupinder; Kumar, V; Prashar, V; Saini, S; Dwivedi, A.R; Bajaj, B; Mehta, D; Parkash, Jyoti; Kumar, VinodAlzheimer's disease (AD) is a multifactorial neurological disorder involving complex pathogenesis. Single target directed drugs proved ineffective and since last few years' different pharmacological strategies including multi-targeting agents are being explored for the effective drug development for AD. A total of 19 dipropargyl substituted diphenylpyrimidines have been synthesized and evaluated for the monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibition potential. All the compounds were found to be selective and reversible inhibitors of MAO-B isoform. These compounds also displayed good AChE inhibition potential with IC50 values in low micromolar range. AVB4 was found to be the most potent MAO-B inhibitor with IC50 value of 1.49 ± 0.09 μM and AVB1 was found to be the most potent AChE inhibitor with IC50 value of 1.35 ± 0.03 μM. In the ROS protection inhibition studies, AVB1 and AVB4 displayed weak but interesting activity in SH-SY5Y cells. In the cytotoxicity studies involving SH-SY5Y cells, both AVB1 and AVB4 were found to be non-toxic to the tissue cells. In the molecular dynamic simulation studies of 30 ns, the potent compounds were found to be quite stable in the active site of MAO-B and AChE. The results suggested that AVB1 and AVB4 are promising dual inhibitors and have the potential to be developed as anti-Alzheimer's drug. © 2019Item Synthesis, biological evaluation and molecular modeling studies of phenyl-/benzhydrylpiperazine derivatives as potential MAO inhibitors.(Elsevier, 2018) Kumar, Bhupinder; Sheetal; Mantha, Anil K.; Kumar, VinodMonoamine oxidase inhibitors (MAOIs) are potential drug candidates for the treatment of various neurological disorders like Parkinson's disease, Alzheimer's disease and depression. In the present study, two series of 4-substituted phenylpiperazine and 1-benzhydrylpiperazine (1-21) derivatives were synthesized and screened for their MAO-A and MAO-B inhibitory activity using Amplex Red assay. Most of the synthesized compounds were found selective for MAO-B isoform except compounds 3, 7, 8, 9 and 13 (MAO-A selective) while compound 11 was non-selective. In the current series, compound 12 showed most potent MAO-B inhibitor activity with IC50 value of 80 nM and compound 7 was found to be most potent MAO-A inhibitor with IC50 value of 120 nM and both the compounds were found reversible inhibitors. Compound 8 was found most selective MAO-A inhibitor while compound 20 was found most selective inhibitor for MAO-B isoform. In the cytotoxicity evaluation, all the compounds were found non-toxic to SH-SY5Y and IMR-32 cells at 25 µM concentration. In the ROS studies, compound 8 (MAO-A inhibitor) reduced the ROS level by 51.2% while compound 13 reduced the ROS level by 61.81%. In the molecular dynamic simulation studies for 30 ns, compound 12 was found quite stable in the active cavity of MAO-B. Thus, it can be concluded that phenyl- and 1-benzhydrylpiperazine derivatives are promising MAO inhibitors and can act as a lead to design potent, and selective MAO inhibitors for the treatment of various neurological disorders.Item Synthesis and biological evaluation of pyrimidine bridged combretastatin derivatives as potential anticancer agents and mechanistic studies(Academic Press Inc., 2018) Kumar, Bhupinder; Sharma, Praveen; Gupta, Vivek Prakash; Khullar, Madhu; Singh, Sandeep; Dogra, Nilambra; Kumar, VinodA number of pyrimidine bridged combretastatin derivatives were designed, synthesized and evaluated for anticancer activities against breast cancer (MCF-7) and lung cancer (A549) cell lines using MTT assays. Most of the synthesized compounds displayed good anticancer activity with IC50 values in low micro-molar range. Compounds 4a and 4p were found most potent in the series with IC50 values of 4.67 ?M & 3.38 ?M and 4.63 ?M & 3.71 ?M against MCF7 and A549 cancer cell lines, respectively. Biological evaluation of these compounds showed that selective cancer cell toxicity (in vitro using human lung and breast cancer cell lines) might be due to the inhibition of antioxidant enzymes instigating elevated ROS levels which triggers intrinsic apoptotic pathways. These compounds were found nontoxic to the normal human primary cells. Compound 4a, was found to be competitive inhibitor of colchicine and in the tubulin binding assay it showed tubulin polymerization inhibition potential comparable to colchicine. The molecular modeling studies also showed that the synthesized compounds fit well in the colchicine-binding pocket. ? 2018 Elsevier Inc.Item Chitosan-supported copper as an efficient and recyclable heterogeneous catalyst for A3/decarboxylative A3-coupling reaction(Elsevier Ltd, 2018) Kaur, Pavneet; Kumar, Bhupinder; Kumar, Vinod; Kumar, RakeshChitosan-supported copper (chit@copper) based heterogeneous catalysts have been explored for A3-coupling and decarboxylative A3-coupling. The developed protocol employs low catalyst loading, solventless condition and easy work-up for the synthesis of diversely substituted propargylamines. More importantly, the catalyst could be recovered and reused without any significant loss in the activity. This offer huge advantages as recyclability issues are rarely addressed in decarboxylative A3-coupling. Leaching studies were carried out using AAS and ICPMS analysis. It is envisaged that chit@copper catalysts can have potential applications in terms of efficiency and recyclability in the emerging area of decarboxylative C?H bond activation/functionalization strategies. ? 2018 Elsevier LtdItem Synthesis, Biological Evaluation and Molecular Modeling Studies of Propargyl‐Containing 2,4,6‐Trisubstituted Pyrimidine Derivatives as Potential Anti‐Parkinson Agents(Wiley, 2018) Kumar, Bhupinder; Kumar, Mohit; Dwivedi, Ashish Ranjan; Kumar, VinodMonoamine oxidase B (MAO‐B) inhibitors are potential drug candidates for the treatment of various neurological disorders including Parkinson's disease. A total of 20 new propargyl‐containing 2,4,6‐trisubstituted pyrimidine derivatives were synthesized and screened for MAO inhibition using Amplex Red assays. All the synthesized compounds were found to be reversible and selective inhibitors of the MAO‐B isoform at sub‐micromolar concentrations. MVB3 was the most potent MAO‐B inhibitor with an IC50 value of 0.38±0.02 μμ, whereas MVB6 (IC50=0.51±0.04 μμ) and MVB16 (IC50=0.48±0.06 μμ) were the most selective for MAO‐B with a selectivity index of more than 100‐fold. In cytotoxic studies, these compounds were found to be nontoxic to human neuroblastoma SH‐SY5Y cells at concentrations of 25 μm. MVB6 was found to decrease the intracellular level of reactive oxygen species to 68 % at 10 μm concentration, whereas other compounds did not produce significant changes in reactive oxygen species levels. In molecular modeling studies, MVB3 displayed strong binding affinity for the MAO‐B isoform with a dock score of −10.45, in agreement with the observed activity. All the compounds fitted well in the hydrophobic cavity of MAO‐B. Thus, propargyl‐substituted pyrimidine derivatives can be promising leads in the development of potent, selective and reversible MAO‐B inhibitors for the treatment of Parkinson's disease.Item Synthesis, biological evaluation and molecular modeling studies of phenyl-/benzhydrylpiperazine derivatives as potential MAO inhibitors(Academic Press Inc., 2018) Kumar, Bhupinder; Sheetal; Mantha, Anil K.; Kumar, VinodMonoamine oxidase inhibitors (MAOIs) are potential drug candidates for the treatment of various neurological disorders like Parkinson's disease, Alzheimer's disease and depression. In the present study, two series of 4-substituted phenylpiperazine and 1-benzhydrylpiperazine (1?21) derivatives were synthesized and screened for their MAO-A and MAO-B inhibitory activity using Amplex Red assay. Most of the synthesized compounds were found selective for MAO-B isoform except compounds 3, 7, 8, 9 and 13 (MAO-A selective) while compound 11 was non-selective. In the current series, compound 12 showed most potent MAO-B inhibitor activity with IC50 value of 80 nM and compound 7 was found to be most potent MAO-A inhibitor with IC50 value of 120 nM and both the compounds were found reversible inhibitors. Compound 8 was found most selective MAO-A inhibitor while compound 20 was found most selective inhibitor for MAO-B isoform. In the cytotoxicity evaluation, all the compounds were found non-toxic to SH-SY5Y and IMR-32 cells at 25 ?M concentration. In the ROS studies, compound 8 (MAO-A inhibitor) reduced the ROS level by 51.2% while compound 13 reduced the ROS level by 61.81%. In the molecular dynamic simulation studies for 30 ns, compound 12 was found quite stable in the active cavity of MAO-B. Thus, it can be concluded that phenyl- and 1-benzhydrylpiperazine derivatives are promising MAO inhibitors and can act as a lead to design potent, and selective MAO inhibitors for the treatment of various neurological disorders. ? 2018 Elsevier Inc.Item Mechanisms of tubulin binding ligands to target cancer cells: Updates on their therapeutic potential and clinical trials(Bentham Science Publishers B.V., 2017) Kumar, Bhupinder; Kumar, Rakesh; Skvortsova, Ira; Kumar, VinodBackground: A number of chemically diverse substances bind to the tubulin and inhibit cell proliferation by disrupting microtubule dynamics. There are four binding sites for the ligands binding to the tubulin; taxane/epothilone and laulimalide/peloruside binding ligands stabilize microtubule while vinca and colchicine binding site agents promote microtubule depolymerization. Most of the tubulin binding ligands disturb the tubulin-microtubule dynamic equilibrium but these may exhibit anticancer activities through different mechanisms. Taxanes and epothilones are widely used cytotoxic agents and are found effective against different types of human malignancies. However, taxanes are susceptible to pgp mediated multi-drug resistance, dose limiting hematopoietic toxicity and cumulative neurotoxicity. Vinca alkaloids are already in clinical practice, but ligands binding to the colchicine site are still in the different stages of clinical trials. Objective: In the current review article, plausible mechanistic details about the interactions of ligands at the binding pocket and subsequent changes in the tubulin structure are described. The review article also illustrated different formulations of the tubulin binding agents in combination with other chemotherapeutic agents and their therapeutic potential against various human malignancies. Conclusion: Tubulin targeting agents emerged as one of the most successful anticancer drugs and a number of structurally different chemical compounds are in advance stages of clinical development. ? 2017 Bentham Science Publishers.Item A Perspective on Monoamine Oxidase Enzyme as Drug Target: Challenges and Opportunities(2017) Kumar, Bhupinder; Gupta, Vivek Prakash; Kumar, VinodThe monoamine oxidase (MAO) enzyme is responsible for the deamination of monoamine neurotransmitters and regulates their concentration in the central and peripheral nervous systems. Imbalance in the concentration of neurotransmitters in the brain and central nervous system is linked with the biochemical pathology of various neurogenic disorders. Irreversible MAO inhibitors were the first line drugs developed for the management of severe depression but most of these were withdrawn from the clinical practice due to their fatal side effects including food-drug interactions. New generations of MAO inhibitors were developed which were reversible and selective for one of the enzyme isoform and showed improved pharmacological profile. The discovery of crystal structure of MAO-A & MAO-B isoforms helped in understanding the drug-receptor interactions at the molecular level and designing of ligands with selectivity for either of the isoforms. The current article provides an overview on the MAO enzyme as potential drug target for different disease states. The article describes catalytic mechanism of MAO enzyme, crystal structures of the two MAO isoforms, traditional MAO inhibitors and various problems associated with their use, new developments in the MAO inhibitors and their potential as therapeutic agents especially in neurological disorders.Item Regioselective alkylation of 1,2,4-triazole using ionic liquids under microwave conditions(Walter de Gruyter GmbH, 2016) Kaur,Ramandeep; Kumar, Bhupinder; Dwivedi, Ashish Ranjan; Kumar, Vinod1-Substituted 1,2,4-triazole derivatives present in a large number of compounds and display a variety of bioactivities such as antibiotic, anti-inflammatory, anti-diabetic, antipsychotic, and anticancer. A regioselective protocol has been developed for the alkylation of 1,2,4- triazole using mild conditions. The 1-alkyl-1,2,4-triazole derivatives were synthesized under microwave conditions using potassium carbonate as a base and ionic liquid (hexylpyridinium bromide) as a solvent. The products were obtained in excellent yield, and the base-ionic liquid combination was recycled for a number of times. ? 2016 by De Gruyter 2016.