101
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Sebastian A, Pandey V, Mohan CD, Chia YT, Rangappa S, Mathai J, Baburajeev CP, Paricharak S, Mervin LH, Bulusu KC, Fuchs JE, Bender A, Yamada S, Lobie PE, Rangappa KS. Novel Adamantanyl-Based Thiadiazolyl Pyrazoles Targeting EGFR in Triple-Negative Breast Cancer. ACS OMEGA 2016; 1:1412-1424. [PMID: 30023509 PMCID: PMC6044684 DOI: 10.1021/acsomega.6b00251] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 12/15/2016] [Indexed: 06/08/2023]
Abstract
The epidermal growth factor receptor (EGFR) is a validated therapeutic target for triple-negative breast cancer (TNBC). In the present study, we synthesize novel adamantanyl-based thiadiazolyl pyrazoles by introducing the adamantane ring to thiazolopyrazoline. On the basis of loss of cell viability in TNBC cells, 4-(adamantan-1-yl)-2-(3-(2,4-dichlorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)thiazole (APP) was identified as a lead compound. Using a Parzen-Rosenblatt Window classifier, APP was predicted to target the EGFR protein, and the same was confirmed by surface plasmon resonance. Further analysis revealed that APP suppressed the phosphorylation of EGFR at Y992, Y1045, Y1068, Y1086, Y1148, and Y1173 in TNBC cells. APP also inhibited the phosphorylation of ERK at Y204 and of STAT3 at Y705, implying that APP downregulates the activity of EGFR downstream effectors. Small interfering RNA mediated depletion of EGFR expression prevented the effect of APP in BT549 and MDA-MB-231 cells, indicating that APP specifically targets the EGFR. Furthermore, APP modulated the expression of the proteins involved in cell proliferation and survival. In addition, APP altered the expression of epithelial-mesenchymal transition related proteins and suppressed the invasion of TNBC cells. Hence, we report a novel and specific inhibitor of the EGFR signaling cascade.
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102
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Ningegowda R, Shivananju NS, Rajendran P, Basappa, Rangappa KS, Chinnathambi A, Li F, Achar RR, Shanmugam MK, Bist P, Alharbi SA, Lim LHK, Sethi G, Priya BS. A novel 4,6-disubstituted-1,2,4-triazolo-1,3,4-thiadiazole derivative inhibits tumor cell invasion and potentiates the apoptotic effect of TNFα by abrogating NF-κB activation cascade. Apoptosis 2016; 22:145-157. [DOI: 10.1007/s10495-016-1312-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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103
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Ananda H, Sharath Kumar KS, Nishana M, Hegde M, Srivastava M, Byregowda R, Choudhary B, Raghavan SC, Rangappa KS. Regioselective synthesis and biological studies of novel 1-aryl-3, 5-bis (het) aryl pyrazole derivatives as potential antiproliferative agents. Mol Cell Biochem 2016; 426:149-160. [DOI: 10.1007/s11010-016-2887-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/10/2016] [Indexed: 02/08/2023]
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104
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Nirvanappa AC, Mohan CD, Rangappa S, Ananda H, Sukhorukov AY, Shanmugam MK, Sundaram MS, Nayaka SC, Girish KS, Chinnathambi A, Zayed ME, Alharbi SA, Sethi G, Rangappa KS. Novel Synthetic Oxazines Target NF-κB in Colon Cancer In Vitro and Inflammatory Bowel Disease In Vivo. PLoS One 2016; 11:e0163209. [PMID: 27685808 PMCID: PMC5042377 DOI: 10.1371/journal.pone.0163209] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 09/06/2016] [Indexed: 02/06/2023] Open
Abstract
Aberrant activation of nuclear factor kappa B (NF-κB) has been linked with the pathogenesis of several proinflammatory diseases including number of cancers and inflammatory bowel diseases. In the present work, we evaluated the anticancer activity of 1,2-oxazines derivatives against colorectal cancer cell lines and identified 2-((2-acetyl-6,6-dimethyl-4-phenyl-5,6-dihydro-2H-1,2-oxazin-3-yl)methyl)isoindoline-1,3-dione (API) as the lead anticancer agent among the tested compounds. The apoptosis inducing effect of API was demonstrated using flow cytometry analysis and measuring the caspase 3/7 activity in API treated cells. Based on the literature on inhibition of NF-κB by oxazines, we evaluated the effect of 1,2-oxazines against the ability of NF-κB binding to DNA, NF-κB-dependent luciferase expression and IκBα phosphorylation. We found that, API abrogate constitutive activation of NF-κB and inhibits IκBα phosphorylation in HCT116 cells. Our in silico analysis revealed the binding of oxazines to the hydrophobic cavity that present between the interface of p65 and IκBα. Given the relevance with aberrant activation of NF-κB in inflammation bowel disease (IBD), we evaluated the effect of API on dextran sulphate sodium-induced IBD mice model. The treatment of IBD induced mice with API decreased the myeloperoxidase activity in colonic extract, modulated the colon length and serum levels of pro- and anti-inflammatory cytokines such as TNF-α, IFN-γ, IL-6, IL-1β and IL-10. Furthermore, the histological analysis revealed the restoration of the distorted cryptic epithelial structure of colon in the API treated animals. In conclusion, we comprehensively validated the NF-κB inhibitory efficacy of API that targets NF-κB in in vitro colon cancer and an in vivo inflammatory bowel disease model.
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105
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Ananda H, Kumar KSS, Hegde M, Rangappa KS. Induction of apoptosis and downregulation of ERα in DMBA-induced mammary gland tumors in Sprague–Dawley rats by synthetic 3,5-disubstituted isoxazole derivatives. Mol Cell Biochem 2016; 420:141-50. [DOI: 10.1007/s11010-016-2777-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/23/2016] [Indexed: 01/16/2023]
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106
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Anusha S, Sinha A, Babu Rajeev CP, Chu TTT, Mathai J, Ximei H, Fuchs JE, Shivananju N, Bender A, Preiser PR, Rangappa KS, Basappa, Chandramohanadas R. Synthesis, characterization and in vitro evaluation of novel enantiomerically-pure sulphonamide antimalarials. Org Biomol Chem 2016; 13:10681-90. [PMID: 26347024 DOI: 10.1039/c5ob01479d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Malaria parasites are currently gaining drug-resistance rapidly, across countries and continents. Hence, the discovery and development of novel chemical scaffolds, with superior antimalarial activity remain an important priority, for the developing world. Our report describes the development, characterization and evaluation of novel bepotastine-based sulphonamide antimalarials inhibiting asexual stage development of Plasmodium falciparum parasites in vitro. The screening results showed potent inhibitory activity of a number of novel sulphonamides against P. falciparum at low micromolar concentrations, in particular in late-stage parasite development. Based on computational studies we hypothesize N-myristoyltransferase as the target of the compounds developed here. Our results demonstrate the value of novel bepotastine-based sulphonamide compounds for targeting the asexual developmental stages of P. falciparum.
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107
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Sivaramakrishnan V, Ilamathi M, Girish KS, Kemparaju K, Rangappa KS, Dhananjaya BL. Viper venom hyaluronidase and its potential inhibitor analysis: a multipronged computational investigation. J Biomol Struct Dyn 2016; 35:1979-1989. [PMID: 27334983 DOI: 10.1080/07391102.2016.1203820] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Viper venom hyaluronidase (VV-HYA) inhibitors have long been used as therapeutic agents for arresting the local and systemic effects caused during its envenomation. Henceforth, to understand its structural features and also to identify the best potential inhibitor against it the present computational study was undertaken. Structure-based homology modeling of VV-HYA followed by its docking and free energy-based ranking analysis of ligand, the MD simulations of the lead complex was also performed. The sequence analysis and homology modeling of VV-HYA revealed a distorted (β/α)8 folding as in the case of hydrolases family of proteins. Molecular docking of the resultant 3D structure of VV-HYA with known inhibitors (compounds 1-25) revealed the importance of molecular recognition of hotspot residues (Tyr 75, Arg 288, and Trp 321) other than that of the active site residues. It also revealed that Trp 321 of VV-HYA is highly important for mediating π-π interactions with ligands. In addition, the molecular docking and comparative free energy binding analysis was investigated for the VV-HYA inhibitors (compounds 1-25). Both molecular docking and relative free energy binding analysis clearly confirmed the identification of sodium chromoglycate (compound 1) as the best potential inhibitor against VV-HYA. Molecular dynamics simulations additionally confirmed the stability of their binding interactions. Further, the information obtained from this work is believed to serve as an impetus for future rational designing of new novel VV-HYA inhibitors with improved activity and selectivity.
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108
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Sulaiman NBS, Mohan CD, Basappa, Pandey V, Rangappa S, Bharathkumar H, Kumar AP, Lobie PE, Rangappa KS. An azaspirane derivative suppresses growth and induces apoptosis of ER-positive and ER-negative breast cancer cells through the modulation of JAK2/STAT3 signaling pathway. Int J Oncol 2016; 49:1221-9. [DOI: 10.3892/ijo.2016.3615] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/28/2016] [Indexed: 11/06/2022] Open
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109
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Subramanian G, Babu Rajeev CP, Mohan CD, Sinha A, Chu TTT, Anusha S, Ximei H, Fuchs JE, Bender A, Rangappa KS, Chandramohanadas R, Basappa. Synthesis and in vitro evaluation of hydrazinyl phthalazines against malaria parasite, Plasmodium falciparum. Bioorg Med Chem Lett 2016; 26:3300-3306. [PMID: 27261180 DOI: 10.1016/j.bmcl.2016.05.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/05/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
In this report, we describe the synthesis of 1-(Phthalazin-4-yl)-hydrazine using bronsted acidic ionic liquids and demonstrate their ability to inhibit asexual stage development of human malaria parasite, Plasmodium falciparum. Through computational studies, we short-listed chemical scaffolds with potential binding affinity to an essential parasite protein, dihydroorotate dehydrogenase (DHODH). Further, these compounds were synthesized in the lab and tested against P. falciparum. Several compounds from our library showed inhibitory activity at low micro-molar concentrations with minimal cytotoxic effects. These results indicate the potential of hydralazine derivatives as reference scaffolds to develop novel antimalarials.
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110
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Hegde M, Mantelingu K, Pandey M, Pavankumar CS, Rangappa KS, Raghavan SC. Combinatorial Study of a Novel Poly (ADP-ribose) Polymerase Inhibitor and an HDAC Inhibitor, SAHA, in Leukemic Cell Lines. Target Oncol 2016; 11:655-665. [DOI: 10.1007/s11523-016-0441-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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111
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Mohan CD, Srinivasa V, Rangappa S, Mervin L, Mohan S, Paricharak S, Baday S, Li F, Shanmugam MK, Chinnathambi A, Zayed ME, Alharbi SA, Bender A, Sethi G, Basappa, Rangappa KS. Trisubstituted-Imidazoles Induce Apoptosis in Human Breast Cancer Cells by Targeting the Oncogenic PI3K/Akt/mTOR Signaling Pathway. PLoS One 2016; 11:e0153155. [PMID: 27097161 PMCID: PMC4838272 DOI: 10.1371/journal.pone.0153155] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 03/24/2016] [Indexed: 12/31/2022] Open
Abstract
Overactivation of PI3K/Akt/mTOR is linked with carcinogenesis and serves a potential molecular therapeutic target in treatment of various cancers. Herein, we report the synthesis of trisubstituted-imidazoles and identified 2-chloro-3-(4, 5-diphenyl-1H-imidazol-2-yl) pyridine (CIP) as lead cytotoxic agent. Naïve Base classifier model of in silico target prediction revealed that CIP targets RAC-beta serine/threonine-protein kinase which comprises the Akt. Furthermore, CIP downregulated the phosphorylation of Akt, PDK and mTOR proteins and decreased expression of cyclin D1, Bcl-2, survivin, VEGF, procaspase-3 and increased cleavage of PARP. In addition, CIP significantly downregulated the CXCL12 induced motility of breast cancer cells and molecular docking calculations revealed that all compounds bind to Akt2 kinase with high docking scores compared to the library of previously reported Akt2 inhibitors. In summary, we report the synthesis and biological evaluation of imidazoles that induce apoptosis in breast cancer cells by negatively regulating PI3K/Akt/mTOR signaling pathway.
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112
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Joshi V, Umashankara M, Ramakrishnan C, Nanjaraj Urs AN, Suvilesh KN, Velmurugan D, Rangappa KS, Vishwanath BS. Dimethyl ester of bilirubin exhibits anti-inflammatory activity through inhibition of secretory phospholipase A2, lipoxygenase and cyclooxygenase. Arch Biochem Biophys 2016; 598:28-39. [PMID: 27060751 DOI: 10.1016/j.abb.2016.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 12/18/2022]
Abstract
Overproduction of arachidonic acid (AA) mediated by secretory phospholipase A2 group IIA (sPLA2IIA) is a hallmark of many inflammatory disorders. AA is subsequently converted into pro-inflammatory eicosanoids through 5-lipoxygenase (5-LOX) and cyclooxygenase-1/2 (COX-1/2) activities. Hence, inhibition of sPLA2IIA, 5-LOX and COX-1/2 activities is critical in regulating inflammation. We have previously reported unconjugated bilirubin (UCB), an endogenous antioxidant, as sPLA2IIA inhibitor. However, lipophilic UCB gets conjugated in liver with glucuronic acid into hydrophilic conjugated bilirubin (CB). Since hydrophobicity is pre-requisite for sPLA2IIA inhibition, conjugation reduces the efficacy of UCB. In this regard, UCB was chemically modified and derivatives were evaluated for sPLA2IIA, 5-LOX and COX-1/2 inhibition. Among the derivatives, BD1 (dimethyl ester of bilirubin) exhibited ∼ 3 fold greater inhibitory potency towards sPLA2IIA compared to UCB. Both UCB and BD1 inhibited human 5-LOX and COX-2 activities; however only BD1 inhibited AA induced platelet aggregation. Molecular docking studies demonstrated BD1 as better inhibitor of aforesaid enzymes than UCB and other endogenous antioxidants. These data suggest that BD1 exhibits strong anti-inflammatory activity through inhibition of AA cascade enzymes which is of great therapeutic importance.
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113
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Sathisha KR, Gopal S, Rangappa KS. Antihyperuricemic effects of thiadiazolopyrimidin-5-one analogues in oxonate treated rats. Eur J Pharmacol 2016; 776:99-105. [PMID: 26875636 DOI: 10.1016/j.ejphar.2016.02.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 10/22/2022]
Abstract
Hyperuricemia is a risk factor for not only gout, but also to a variety of disorders that affect the vital organ systems of the human body. The xanthine oxidase (XO) is the key enzyme in the production of uric acid and its inhibition can inhibit hyperuricemia. Although, XO inhibitor allopurinol is widely prescribed antigout agent but its use is not without any side effects. Previously, we described the synthesis of four novel thiadiazolopyrimidin-5-one analogues as effective XO inhibitors and molecular docking studies also confirmed this. When these analogues were tested in potassium oxonate treated rats, their serum uric acid and creatinine levels were dropped significantly from 4.85±0.03 mg/dl to 1.21±0.01 mg/dl and 0.92±0.02 mg/dl to 0.40±0.02 mg/dl respectively. Among the pyrimidine analogues tested, 6a was most potent. Histological examinations of both liver and kidney tissues exhibited severe necrosis in oxonate treated rats and pyrimidine analogues could significantly attenuate this with a correlative inhibitory profile of hepatic XO from the same rats. Our results demonstrate antihyperuricemic effect of novel thiadiazolopyrimidin-5-one analogues in oxonate treated rats, which can be further explored not only as antigout therapeutics but also in other systems where hyperuricemia is the driving cause of the disease.
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114
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Hegde M, Mantelingu K, Swarup HA, Pavankumar CS, Qamar I, Raghavan SC, Rangappa KS. Novel PARP inhibitors sensitize human leukemic cells in an endogenous PARP activity dependent manner. RSC Adv 2016. [DOI: 10.1039/c5ra19150e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Poly(ADP-ribose) polymerase (PARP) is a critical nuclear enzyme which helps in DNA repair. In this study we report, synthesis and biological studies of novel pyridazine derivatives as PARP inhibitors.
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115
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Vinayaka AC, Swaroop TR, Chikkade PK, Rangappa KS, Sadashiva MP. Transition-metal-free solid phase synthesis of 1,2-disubstituted 4-quinolones via the regiospecific synthesis of enaminones. RSC Adv 2016. [DOI: 10.1039/c5ra21421a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The transition-metal-free economical solid phase synthesis of 1,2-disubstituted 4-quinolones has been developed via the novel regiospecific synthesis of enaminones.
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116
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Baburajeev CP, Mohan CD, Patil GS, Rangappa S, Pandey V, Sebastian A, Fuchs JE, Bender A, Lobie PE, Basappa B, Rangappa KS. Nano-cuprous oxide catalyzed one-pot synthesis of a carbazole-based STAT3 inhibitor: a facile approach via intramolecular C–N bond formation reactions. RSC Adv 2016. [DOI: 10.1039/c6ra01906d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In this study, we report the one-pot synthesis of substituted carbazole derivatives using nano cuprous oxide as a catalyst and demonstrated the STAT3 inhibitory activity of new compounds.
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117
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Nandeesh KN, Swarup HA, Sandhya NC, Mohan CD, Pavan Kumar CS, Kumara MN, Mantelingu K, Ananda S, Rangappa KS. Synthesis and antiproliferative efficiency of novel bis(imidazol-1-yl)vinyl-1,2,4-oxadiazoles. NEW J CHEM 2016. [DOI: 10.1039/c5nj02925b] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new class of bis(imidazol)vinyl-1,2,4-oxadiazoles were synthesised and their anti-proliferative efficiency was tested against HCT116 and A549 cancer cell lines.
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118
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Ramesha AB, Sandhya NC, Pavan Kumar CS, Hiremath M, Mantelingu K, Rangappa KS. A novel approach for the synthesis of imidazo and triazolopyridines from dithioesters. NEW J CHEM 2016. [DOI: 10.1039/c6nj01038e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Various imidazo- and triazolo-pyridines were synthesised by the intramolecular cyclization of pyridine 2-methylamine and dithioesters under mild conditions.
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119
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Anusha S, Mohan CD, Ananda H, Baburajeev CP, Rangappa S, Mathai J, Fuchs JE, Li F, Shanmugam MK, Bender A, Sethi G, Basappa, Rangappa KS. Adamantyl-tethered-biphenylic compounds induce apoptosis in cancer cells by targeting Bcl homologs. Bioorg Med Chem Lett 2015; 26:1056-1060. [PMID: 26725030 DOI: 10.1016/j.bmcl.2015.12.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 11/12/2015] [Accepted: 12/10/2015] [Indexed: 02/05/2023]
Abstract
Bcl homologs prominently contribute to apoptotic resistance in cancer cells and serve as molecular targets in treatment of various cancers. Herein, we report the synthesis of biphenyl-adamantane derivatives by a ligand free palladium on carbon based Suzuki reaction using diisopropylamine as a base for the coupling of adamantane based aryl chloride with a variety of aryl boronic acids. Among the biphenyl derivatives synthesized, compound 3'-(adamantan-1-yl)-4'-methoxy-[1,1'-biphenyl]-3-ol (AMB) displayed cytotoxic activity against hepatocellular carcinoma cell lines without significantly affecting the normal cell lines. Further, AMB caused increased accumulation of the HCC cells in subG1 phase, decreased the expression of Bcl-2, Bcl-xL, cyclin D1, caspase-3, survivin and increased the cleavage of PARP in a time-dependent manner. In silico molecular interaction studies between Bcl homologs and AMB showed that the biphenyl scaffold is predicted to form π-π interactions with Phe-101 and Tyr-105 and the adamantyl fragment is predicted to occupy another hydrophobic region in the kink region of the binding groove. In summary, we report on the synthesis and biological characterization of adamantyl-tethered biphenylic compounds that induce apoptosis in tumor cells most likely by targeting Bcl homologs.
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120
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Baburajeev CP, Dhananjaya Mohan C, Ananda H, Rangappa S, Fuchs JE, Jagadish S, Sivaraman Siveen K, Chinnathambi A, Ali Alharbi S, Zayed ME, Zhang J, Li F, Sethi G, Girish KS, Bender A, Basappa, Rangappa KS. Development of Novel Triazolo-Thiadiazoles from Heterogeneous "Green" Catalysis as Protein Tyrosine Phosphatase 1B Inhibitors. Sci Rep 2015; 5:14195. [PMID: 26388336 PMCID: PMC4585680 DOI: 10.1038/srep14195] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 08/18/2015] [Indexed: 02/06/2023] Open
Abstract
Condensed-bicyclic triazolo-thiadiazoles were synthesized via an efficient "green" catalyst strategy and identified as effective inhibitors of PTP1B in vitro. The lead compound, 6-(2-benzylphenyl)-3-phenyl-[1,2,4]triazolo[3][1,3,4]thiadiazole (BPTT) was most effective against human hepatoma cells, inhibits cell invasion, and decreases neovasculature in HUVEC and also tumor volume in EAT mouse models. This report describes an experimentally unidentified class of condensed-bicyclic triazolo-thiadiazoles targeting PTP1B and its analogs could be the therapeutic drug-seeds.
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121
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Sharath Kumar KS, Hanumappa A, Vetrivel M, Hegde M, Girish YR, Byregowda TR, Rao S, Raghavan SC, Rangappa KS. Antiproliferative and tumor inhibitory studies of 2,3 disubstituted 4-thiazolidinone derivatives. Bioorg Med Chem Lett 2015; 25:3616-20. [DOI: 10.1016/j.bmcl.2015.06.069] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/05/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
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122
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Raghavendra GM, Pavan Kumar CS, Suresha GP, Rangappa KS, Mantelingu K. T3P catalyzed one pot three-component synthesis of 2,3-disubstituted 3H-quinazolin-4-ones. CHINESE CHEM LETT 2015. [DOI: 10.1016/j.cclet.2015.03.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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123
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Sivaramakrishnan V, Ilamathi M, Ghosh KS, Sathish S, Gowda TV, Vishwanath BS, Rangappa KS, Dhananjaya BL. Virtual analysis of structurally diverse synthetic analogs as inhibitors of snake venom secretory phospholipase A2. J Mol Recognit 2015. [PMID: 26218369 DOI: 10.1002/jmr.2492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Due to the toxic pathophysiological role of snake venom phospholipase A2 (PLA2 ), its compelling limitations to anti-venom therapy in humans and the need for alternative therapy foster considerable pharmacological interest towards search of PLA2 specific inhibitors. In this study, an integrated approach involving homology modeling, molecular dynamics and molecular docking studies on VRV-PL-V (Vipera russellii venom phospholipase A2 fraction-V) belonging to Group II-B secretory PLA2 from Daboia russelli pulchella is carried out in order to study the structure-based inhibitor design. The accuracy of the model was validated using multiple computational approaches. The molecular docking study of this protein was undertaken using different classes of experimentally proven, structurally diverse synthetic inhibitors of secretory PLA2 whose selection is based on IC50 value that ranges from 25 μM to 100 μM. Estimation of protein-ligand contacts by docking analysis sheds light on the importance of His 47 and Asp 48 within the VRV-PL-V binding pocket as key residue for hydrogen bond interaction with ligands. Our virtual analysis revealed that compounds with different scaffold binds to the same active site region. ADME analysis was also further performed to filter and identify the best potential specific inhibitor against VRV-PL-V. Additionally, the e-pharmacophore was generated for the best potential specific inhibitor against VRV-PL-V and reported here. The present study should therefore play a guiding role in the experimental design of VRV-PL-V inhibitors that may provide better therapeutic molecular models for PLA2 recognition and anti-ophidian activity.
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124
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Anilkumar NC, Sundaram MS, Mohan CD, Rangappa S, Bulusu KC, Fuchs JE, Girish KS, Bender A, Basappa, Rangappa KS. A One Pot Synthesis of Novel Bioactive Tri-Substitute-Condensed-Imidazopyridines that Targets Snake Venom Phospholipase A2. PLoS One 2015; 10:e0131896. [PMID: 26196520 PMCID: PMC4511007 DOI: 10.1371/journal.pone.0131896] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 06/08/2015] [Indexed: 12/22/2022] Open
Abstract
Drugs such as necopidem, saripidem, alpidem, zolpidem, and olprinone contain nitrogen-containing bicyclic, condensed-imidazo[1,2-α]pyridines as bioactive scaffolds. In this work, we report a high-yield one pot synthesis of 1-(2-methyl-8-aryl-substitued-imidazo[1,2-α]pyridin-3-yl)ethan-1-onefor the first-time. Subsequently, we performed in silico mode-of-action analysis and predicted that the synthesized imidazopyridines targets Phospholipase A2 (PLA2). In vitro analysis confirmed the predicted target PLA2 for the novel imidazopyridine derivative1-(2-Methyl-8-naphthalen-1-yl-imidazo [1,2-α]pyridine-3-yl)-ethanone (compound 3f) showing significant inhibitory activity towards snake venom PLA2 with an IC50 value of 14.3 μM. Evidently, the molecular docking analysis suggested that imidazopyridine compound was able to bind to the active site of the PLA2 with strong affinity, whose affinity values are comparable to nimesulide. Furthermore, we estimated the potential for oral bioavailability by Lipinski's Rule of Five. Hence, it is concluded that the compound 3f could be a lead molecule against snake venom PLA2.
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Bharathkumar H, Mohan CD, Rangappa S, Kang T, Keerthy HK, Fuchs JE, Kwon NH, Bender A, Kim S, Basappa, Rangappa KS. Screening of quinoline, 1,3-benzoxazine, and 1,3-oxazine-based small molecules against isolated methionyl-tRNA synthetase and A549 and HCT116 cancer cells including an in silico binding mode analysis. Org Biomol Chem 2015; 13:9381-7. [PMID: 26159576 DOI: 10.1039/c5ob00791g] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Elevated activity of methionyl-tRNA synthetase (MRS) in many cancers renders it a possible drug target in this disease area, as well as in a series of parasitic diseases. In the present work, we report the synthesis and in vitro screening of a library of 1,3-oxazines, benzoxazines and quinoline scaffolds against human MRS. Among the compounds tested, 2-(2-butyl-4-chloro-1-(4-phenoxybenzyl)-1H-imidazol-5-yl)-5-(4-methoxyphenyl)-1-oxa-3-azaspiro[5.5]undecane (compound 21) and 2-(2-butyl-4-chloro-1-(4-nitrobenzyl)-1H-imidazol-5-yl)-2,4-dihydro-1H-benzo[d][1,3]oxazine (compound 8) were found to be potent inhibitors of MRS. Additionally, these compounds significantly suppressed the proliferation of A549 and HCT116 cells with IC50 values of 28.4, 17.7, 41.9, and 19.8 μM respectively. Molecular docking studies suggested that the ligand binding orientation overlaps with the original positions of both methionine and adenosine of MRS. This suggests the binding of compound 21 against MRS, which might lead the inhibitory activity towards cancer cells.
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