Department Of Pharmaceutical Sciences and Natural Products
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Item Knoevenagel/tandem knoevenagel and michael adducts of cyclohexane-1,3-dione and aryl aldehydes: Synthesis, DFT studies, xanthine oxidase inhibitory potential, and molecular modeling(American Chemical Society, 2019) Arora, S; Joshi, G; Kalra, S; Wani, A.A; Bharatam, P.V; Kumar, Pradeep; Kumar, RajXanthine oxidase (XO) plays a crucial role in the formation of uric acid by oxidative hydroxylation of purines. Herein, we report the design and synthesis of Knoevenagel/tandem Knoevenagel and Michael adducts of cyclohexane-1,3-dione and aryl aldehydes as nonpurine XO inhibitors derived from naturally occurring scaffolds. Density functional theory calculations highlighted the reaction pathways and reasoned the formation of tandem Knoevenagel and Michael adducts. The synthetics were assessed for their XO inhibitory potential, and among them, four compounds (1b, 1g, 2b, and 3a) were found to possess best IC 50 values in the range of 3.66-4.98 μM. Interestingly, Knoevenagel adducts exhibited a competitive-type inhibition, whereas tandem Knoevenagel and Michael adducts produced a noncompetitive mode of inhibition. The compounds were capable of reducing the H 2 O 2 levels induced by XO, both in normal and cancer cells with no significant cytotoxicity. Molecular modeling studies highlighted the role of interactions of compounds with residual amino acids of the XO active site and also corroborated with the observed structure-activity relationship. © 2019 American Chemical Society.Item Pd-Catalyzed Four-Component Sequential Reaction Delivers a Modular Fluorophore Platform for Cell Imaging(American Chemical Society, 2019) Ansari, A.J; Joshi, G; Sharma, P; Maurya, A.K; Metre, R.K; Agnihotri, V.K; Chandaluri, C.G; Kumar, Raj; Singh, S; Sawant, D.M.A Pd-catalyzed cascade reaction of four versatile privileged synthons is described. The sequential reaction involves the formation of five new chemical bonds by concatenating three distinct chemical steps. One of the derivatives exhibited absorption in the visible region, fluorescence with a high quantum yield, and excellent photostability. Its application is explored in live cell imaging, which exhibited cytoplasmic and mitochondrial specific staining with no toxicity. © 2019 American Chemical Society.Item 2-(2-Arylphenyl) benzoxazole As a Novel Anti-Inflammatory Scaffold: Synthesis and Biological Evaluation(ACS publications, 2014) Seth, Kapileswar; Garg, Sanjeev K.; Kumar, Raj; Purohit, Priyank; Meena, Vachan S.; Goyal, Rohit; Banerjee, Uttam C.; Chakraborti, Asit K.The 2-(2-arylphenyl)benzoxazole moiety has been found to be a new and selective ligand for the enzyme cyclooxygenase-2 (COX-2). The 2-(2-arylphenyl)benzoxazoles 3a−m have been synthesized by Suzuki reaction of 2-(2-bromophenyl)benzoxazole. Further synthetic manipulation of 3f and 3i led to 3o and 3n, respectively. The compounds 3g, 3n, and 3o selectively inhibited COX-2 with selectivity index of 3n much better than that of the COX-2 selective NSAID celecoxib. The in vivo anti-inflammatory potency of 3g and 3n is comparable to that of celecoxib and the nonselective NSAID diclofenac at two different doses, and 3o showed better potency compared to these clinically used NSAIDs.Item 1-Acetyl-3, 5?diaryl-4, 5?dihydro (1H) pyrazoles: Exhibiting Anticancer Activity through Intracellular ROS Scavenging and the Mitochondria-Dependent Death Pathway(Wiley, 2014) Alex, JM; Singh, S; Kumar, RajA series of 17 analogs of 1?acetyl?4,5?dihydro(1H)pyrazoles (JP?1 to JP?17) bearing two aromatic rings at positions 3 and 5, either of which ought to be heterocyclic, were synthesized and evaluated for their anti?proliferative potential against breast cancer (MCF?7 and T?47D) and lung cancer (H?460 and A?549) cell lines for the first time.JP-1–7, -10, -11, -14, and ?15 were observed to exhibit significant anti?proliferative activity against MCF?7 cells. Some notions about structure - activity relationships are reported. The investigated compounds were found to lower the intracellular reactive oxygen species in the H2DCFDA assay and also caused mitochondria?dependent cell death in the MCF?7 cell line, indicating a plausible mechanism of their anticancer effect.Item Relay tricyclic Pd (ii)/Ag (i) catalysis: design of a four-component reaction driven by nitrene-transfer on isocyanide yields inhibitors of EGFR.(Royal Society of Chemistry, 2018) Sawant, D.M.; Sharma, S; Pathare, R.S; Joshi, G; Kalra, S; Sukanya, S; Maurya, A.K.; Metre, R.K; Agnihotri, V.K.; Khan, S.; Kumar, Raj; Pardasania, R. T.Synthesis of pyrazolo[1,5-c]quinazolines from four easily available precursors is presented through a one-pot tricyclic Pd(II)/Ag(I) relay catalysis. The bimetallic relay cascade forges five new chemical bonds by concatenating six discrete chemical steps. The relay catalysis enables four-component assembly of pyrazolo[1,5-c]quinazolines that selectively inhibit EGFR, exhibit apoptosis through the ROS-induced mitochondrial-mediated pathway, and arrest the cell cycle at the G1 phase.Item Association of CYP2C19*2 and ALDH1A1*1/*2 variants with disease outcome in breast cancer patients: results of a global screening array.(Springer, 2018) Kalra, Sourav; Ludhiadch Abhilash; Shafi, Gowhar; Vashista, Rajesh; Kumar, Raj; Munshi, AnjanaCyclophosphamide and doxorubicin (adjuvant chemotherapy) are commonly used to treat breast cancer patients. Variation in the genes involved in pharmacodynamics and pharmacokinetics of these drugs plays an important role in prediction of drug response and survival. The present study was carried out with an aim to evaluate the variation in all the genes involved in pharmacokinetic and pharmacodynamics pathways of cyclophosphamide and doxorubicin, and correlate specific variants with disease outcome in breast cancer patients from the Malwa region of Punjab.Item Unanticipated Cleavage of 2-Nitrophenyl-Substituted N-Formyl Pyrazolines under Bechamp Conditions: Unveiling the Synthesis of 2-Aryl Quinolines and Their Mechanistic Exploration via DFT Studies(American Chemical Society, 2018) Joshi, Gaurav; Wani, Aabid Abdullah; Sharma, Sahil; Bhutani, Priyadeep; Bharatam, Prasad V.; Paul, Atish T.; Kumar, RajWe herein report for the first time an unusual decomposition of 2-nitrophenyl-substituted N-formyl pyrazolines under Bechamp reduction condition employed to yield 2-aryl quinolines exclusively instead of pyrazolo[1,5-c]quinazolines. The reaction investigation suggests acid-mediated cleavage of 1 followed by a retro-Michael addition, and a subsequent in situ intramolecular reductive cyclization through a modified Friedlander mechanism afforded 2-aryl quinolines (2) in good yields. The proposed mechanistic pathways were supported via experimental evidence and density functional theory studies. B3LYP/6-31+G(d) analysis indicated the involvement of trans-2-hydroxyaminochalcone as a key intermediate and its isomerization and cyclization, leading to unusual product formation.Item C-N and N-N bond formation via reductive cyclization: Progress in cadogan/cadogan-sundberg reaction(Wiley-Blackwell, 2018) Kaur, M.; Kumar, RajCadogan/Cadogan-Sundberg cyclization reaction has been reported as one of the most efficient routes for the synthesis of a wide variety of N-heterocycles from the easily accessible starting materials such as o-nitrobiaryls or o-nitroarenes, onitrostyrenes by treating with tetravalent phosphorus compounds (trialkyl or triaryl phosphines or trialkyl phosphites). The reaction has been successfully employed in Carbon-Carbon as well as Carbon-Nitrogen bond formation for the scaffolds like carbazole, indoles, coumarins, and indazoles. To the best of authors'knowledge, the present review is the first compilation of the literature from almost two decades (2000 to present) on Cadogan/Cadogan-Sundberg cyclization reaction, its scope, mechanistic aspects, and limitations.Item 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, RajThe 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 GesellschaftItem 4,5-Dihydro-1H-pyrazole: An indispensable scaffold(Informa Healthcare, 2014) Alex, Jimi Marin; Kumar, RajPyrazoles, categorized as nitrogen-containing heterocycles, are well known for their interminable participation in the field of perpetual research and development of therapeutical active agents. As a consequence pyrazoles became an inevitable core of numerous drugs having diverse activities. The broad spectrum of activities portrayed by the pyrazoles instigated the researchers to modify the pyrazole ring as 4,5-dihydro-1H-pyrazoles commonly known as 2-pyrazolines. The present review is a concerted effort to retrace compounds covered from 2009-till date which owe diverse biological activities to the 2-pyrazoline scaffold and also condenses the retro-synthetic approaches employed for their synthesis. This endeavor culminated in revelation that inhibitory potential varied when the substituents in particular N-substituents of 2-pyrazolines were altered. ? 2014 Informa UK Ltd.