Browsing by Author "Kumar V."
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Item Comparative analysis of metabolites in contrasting chickpea cultivars(Springer, 2019) Ghosh A.; Dadhich A.; Bhardwaj P.; Babu J.N.; Kumar V.Chickpea (Cicer arietinum L.) is a good source of nutrients for animals and human consumption. In the present study, we analyzed the anthocyanin and total phenolic contents in two contrasting (desi and kabuli) chickpea cultivars. The quantification of anthocyanins showed higher amount in desi as compared to kabuli chickpea. The total phenolic contents was estimated in desi and kabuli chickpea using two different solvents (50% Acetone and 70% Methanol extracts) for coverage of all potential phenolic compounds. In continuation, desi chickpea culitvars (himchana and ICC4958) were found to be significantly higher total phenolic contents (in both solvent extracts) as compared to kabuli cultivars (JGK-03 and L-552). Higher phenolic contents was found to be directly correlated to higher anthocyanin contents in desi as compared to kabuli chickpea. The volatile organic compounds were also analyzed using gas chromatography mass spectroscopy technique in both cultivars. The significant compositional differences in volatile organic composition (polar and non-polar) of desi and kabuli cultivars were also found to be noticed using two different solvent extractions (methanol and chloroform). The comparative analysis of volatile organic acids in methanolic and chloroform extracts of desi cultivars (himchana and ICC4958), kabuli cultivars (JGK-03 and L-552) and between desi and kabuli cultivars was also carried out for in-depth understanding of the differential patterns of low molecular weight metabolites. Six metabolites were found to be common in all four selected cultivars in chloroform extracted samples, while four were found to be common in all four selected cultivars in methanolic extracted samples. The remaining detected metabolites are uncommon among different cultivars and represented as cultivar specific signatory metabolites. In conclusion, the present investigation revealed higher anthocyanin and phenolic contents in desi cultivars as compared to kabuli cultivars and differential accumulation of volatile organic compounds in chickpea cultivars. The metabolite alterations among desi and chickpea cultivars could be the potential attribute for diversity, resilience and commercial usuages.Item Metal- And Solvent-Free Multicomponent Decarboxylative A3-Coupling for the Synthesis of Propargylamines: Experimental, Computational, and Biological Investigations(American Chemical Society, 2020) Kaur P.; Kumar B.; Gurjar K.K.; Kumar R.; Kumar V.; Kumar R.Decarboxylative A3-coupling of ortho-hydroxybenzaldehydes, secondary amines, and alkynoic acids is performed under catalyst and solvent-free conditions. The developed methodology provided a waste-free method for the synthesis of hydroxylated propargylamines which are versatile precursors for various bioactive heterocyclic scaffolds. The experimental and density functional theory studies revealed that the in situ-formed ortho-quinonoid intermediate (formed from ortho-hydroxybenzaldehyde and amine) undergoes a concerted Eschweiler-Clarke type decarboxylation with alkynoic acids. The synthesized compounds were evaluated for MAO-A, MAO-B, and AChE inhibitory activities as potential drug candidates for the treatment of various neurological disorders. Compound 4f was found to be the most potent and selective MAO-B (high selectivity over MAO-A) and AChE inhibitor in the series with IC50 values of 4.27 ± 0.07 and 0.79 ± 0.03 ?M, respectively.Item PPInS: a repository of protein-protein interaction sitesbase(Nature Publishing Group, 2018) Kumar V.; Mahato S.; Munshi, Anjana; Kulharia, MaheshProtein-Protein Interaction Sitesbase (PPInS), a high-performance database of protein-protein interacting interfaces, is presented. The atomic level information of the molecular interaction happening amongst various protein chains in protein-protein complexes (as reported in the Protein Data Bank [PDB]) together with their evolutionary information in Structural Classification of Proteins (SCOPe release 2.06), is made available in PPInS. Total 32468 PDB files representing X-ray crystallized multimeric protein-protein complexes with structural resolution better than 2.5 Å had been shortlisted to demarcate the protein-protein interaction interfaces (PPIIs). A total of 111857 PPIIs with ~32.24 million atomic contact pairs (ACPs) were generated and made available on a web server for on-site analysis and downloading purpose. All these PPIIs and protein-protein interacting patches (PPIPs) involved in them, were also analyzed in terms of a number of residues contributing in patch formation, their hydrophobic nature, amount of surface area they contributed in binding, and their homo and heterodimeric nature, to describe the diversity of information covered in PPInS. It was observed that 42.37% of total PPIPs were made up of 6-20 interacting residues, 53.08% PPIPs had interface area ?1000 Å 2 in PPII formation, 82.64% PPIPs were reported with hydrophobicity score of ?10, and 73.26% PPIPs were homologous to each other with the sequence similarity score ranging from 75-100%. A subset ''Non-Redundant Database (NRDB)'' of the PPInS containing 2265 PPIIs, with over 1.8 million ACPs corresponding to the 1931 protein-protein complexes (PDBs), was also designed by removing structural redundancies at the level of SCOP superfamily (SCOP release 1.75). The web interface of the PPInS (http://www.cup.edu.in:99/ppins/home.php) offers an easy-to-navigate, intuitive and user-friendly environment, and can be accessed by providing PDB ID, SCOP superfamily ID, and protein sequence. - 2018, The Author(s).Item Recent advances in decarboxylative C-C bond formation using direct or in situ generated alkenyl acids(Taylor and Francis Inc., 2019) Kaur P.; Kumar V.; Kumar R.In recent years, the reactions of abundantly available, inexpensive, and structurally diverse alkenyl acids (-C=C-COOH) with C-X (X = halogen) or C-H coupling partner have emerged as vital strategies for the streamlined synthesis of functionalized alkenes with extrusion of innocuous CO2. Various alkenyl acids such as cinnamic acids can act as stable surrogates for the polymerization prone styrenes/olefins, which otherwise need special attention for their handling and storage. Furthermore, cinnamic acids can be easily prepared through various methodologies including Knoevenagel-Doebner (KD) condensation, Heck coupling reaction, etc. Recently, various one-pot tandem methodologies involving the decarboxylative coupling of KD/Heck sequence with C-H or C-X substrate have come into fore. The present review article edifies about the recent advances, scope and limitations for C-C bond formation via (i) direct decarboxylative functionalization of C-X or C-H substrate with alkenyl acids, (ii) tandem one-pot multicomponent decarboxylative approaches (involving in situ generated alkenyl acids) e.g. coupling of KD/Heck sequences with C-X or C-H substrate.Item Synthesis, Biological Evaluation and Molecular Modeling Studies of Propargyl-Containing 2,4,6-Trisubstituted Pyrimidine Derivatives as Potential Anti-Parkinson Agents(John Wiley and Sons Ltd, 2018) Kumar B.; Kumar M.; Dwivedi A.R.; Kumar V.Monoamine 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 SAR studies of 14?-phenylacetyl substituted 17-cyclopropylmethyl-7, 8-dihydronoroxymorphinones derivatives: Ligands with mixed NOP and opioid receptor profile(Frontiers Media S.A., 2018) Kumar V.; Polgar W.E.; Cami-Kobeci G.; Thomas M.P.; Khroyan T.V.; Toll L.; Husbands S.M.A series of 14?-acyl substituted 17-cyclopropylmethyl-7,8-dihydronoroxymorphinone compounds has been synthesized and evaluated for affinity and efficacy for mu (MOP), kappa (KOP), and delta (DOP) opioid receptors and nociceptin/orphanin FQ peptide (NOP) receptors. The majority of the new ligands displayed high binding affinities for the three opioid receptors, and moderate affinity for NOP receptors. The affinities for NOP receptors are of particular interest as most classical opioid ligands do not bind to NOP receptors. The predominant activity in the [35S]GTP?S assay was partial agonism at each receptor. The results are consistent with our prediction that an appropriate 14? side chain would access a binding site within the NOP receptor and result in substantially higher affinity than displayed by the parent compound naltrexone. Molecular modeling studies, utilizing the recently reported structure of the NOP receptor, are also consistent with this interpretation.