201
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Grosse S, Pillard C, Massip S, Léger JM, Jarry C, Bourg S, Bernard P, Guillaumet G. Efficient synthesis and first regioselective C-3 direct arylation of imidazo[1,2-b]pyrazoles. Chemistry 2012; 18:14943-7. [PMID: 23086664 DOI: 10.1002/chem.201202593] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/07/2012] [Indexed: 01/13/2023]
Abstract
Highly regioselective: An efficient synthesis of the imidazo[1,2-b]pyrazole core has been developed, and the first regioselective palladium-catalyzed direct arylation of the C-3 position is described (see scheme). Good to excellent yields were obtained for a wide range of aryl partners with electron-rich and electron-poor substituents. This methodology allows rapid access to a large variety of imidazo[1,2-b]pyrazole products and could open the way to the design of new biologically active compounds.
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Affiliation(s)
- Sandrine Grosse
- Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans, UMR-CNRS 7311, BP 6759, rue de Chartres, 45067 Orléans cedex 2, France
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202
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Shukla NM, Salunke DB, Yoo E, Mutz CA, Balakrishna R, David SA. Antibacterial activities of Groebke-Blackburn-Bienaymé-derived imidazo[1,2-a]pyridin-3-amines. Bioorg Med Chem 2012; 20:5850-63. [PMID: 22925449 PMCID: PMC3448811 DOI: 10.1016/j.bmc.2012.07.052] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 10/28/2022]
Abstract
We sought to explore the imidazo[1,2-a]pyridin-3-amines for TLR7 (or 8)-modulatory activities. This chemotype, readily accessed via the Groebke-Blackburn-Bienaymé multi-component reaction, resulted in compounds that were TLR7/8-inactive, but exhibited bacteriostatic activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). To investigate the mechanism of antibacterial activity of this new chemotype, a resistant strain of S. aureus was generated by serially passaging the organism in escalating doses of the most active analogue. A comparison of minimum inhibitory concentrations (MICs) of known bacteriostatic agents in wild-type and resistant strains indicates a novel mechanism of action. Structure-activity relationship studies have led to the identification of positions on the scaffold for additional structural modifications that should allow for the introduction of probes designed to examine cognate binding partners and molecular targets, while not significantly compromising antibacterial potency.
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Affiliation(s)
| | | | - Euna Yoo
- Department of Medicinal Chemistry, University of Kansas
| | - Cole A. Mutz
- Department of Medicinal Chemistry, University of Kansas
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203
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Guchhait SK, Kandekar S, Kashyap M, Taxak N, Bharatam PV. C–H Bond Functionalization Under Metalation–Deprotonation Process: Regioselective Direct Arylation of 3-Aminoimidazo[1,2-a]pyrazine. J Org Chem 2012; 77:8321-8. [DOI: 10.1021/jo301065s] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Sankar K. Guchhait
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Mohali, 160062, Punjab, India
| | - Somnath Kandekar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Mohali, 160062, Punjab, India
| | - Maneesh Kashyap
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Mohali, 160062, Punjab, India
| | - Nikhil Taxak
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Mohali, 160062, Punjab, India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Mohali, 160062, Punjab, India
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204
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Salunke DB, Yoo E, Shukla NM, Balakrishna R, Malladi SS, Serafin KJ, Day VW, Wang X, David SA. Structure-activity relationships in human Toll-like receptor 8-active 2,3-diamino-furo[2,3-c]pyridines. J Med Chem 2012; 55:8137-51. [PMID: 22924757 DOI: 10.1021/jm301066h] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In our ongoing search toward identifying novel and synthetically simpler candidate vaccine adjuvants, we hypothesized that the imidazo[1,2-a]pyrazines, readily accessible via the Groebke-Blackburn-Bienaymé multicomponent reaction, would possess sufficient structural similarity with TLR7/8-agonistic imidazoquinolines. With pyridoxal as the aldehyde component, furo[2,3-c]pyridines, rather than the expected imidazo[1,2-a]pyridines, were obtained, which were characterized by NMR spectroscopy and crystallography. Several analogues were found to activate TLR8-dependent NF-κB signaling. In a focused library of furo[2,3-c]pyridines, a distinct SAR was observed with varying substituents at C2. In human PBMCs, none of the furo[2,3-c]pyridines showed any proinflammatory cytokine induction but upregulated several chemokine ligand genes. In immunization studies in rabbits, the most active compound showed prominent adjuvantic effects. The complete lack of proinflammatory cytokine induction coupled with strong adjuvantic activity of the novel furo[2,3-c]pyridines render this hitherto unknown chemotype an attractive class of compounds which are expected to be devoid of local or systemic reactogenicity.
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Affiliation(s)
- Deepak B Salunke
- Department of Medicinal Chemistry, University of Kansas, Multidisciplinary Research Building, Room 320D, 2030 Becker Drive, Lawrence, Kansas 66047, USA
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205
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Dong G, Wang S, Miao Z, Yao J, Zhang Y, Guo Z, Zhang W, Sheng C. New Tricks for an Old Natural Product: Discovery of Highly Potent Evodiamine Derivatives as Novel Antitumor Agents by Systemic Structure–Activity Relationship Analysis and Biological Evaluations. J Med Chem 2012; 55:7593-613. [DOI: 10.1021/jm300605m] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Guoqiang Dong
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Shengzheng Wang
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Zhenyuan Miao
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Jianzhong Yao
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Yongqiang Zhang
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Zizhao Guo
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Wannian Zhang
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
| | - Chunquan Sheng
- Department of Medicinal
Chemistry, School of Pharmacy, Second Military Medical University,
325 Guohe Road, Shanghai 200433, People’s Republic of China
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206
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Auzanneau C, Montaudon D, Jacquet R, Puyo S, Pouységu L, Deffieux D, Elkaoukabi-Chaibi A, De Giorgi F, Ichas F, Quideau S, Pourquier P. The polyphenolic ellagitannin vescalagin acts as a preferential catalytic inhibitor of the α isoform of human DNA topoisomerase II. Mol Pharmacol 2012; 82:134-41. [PMID: 22528119 DOI: 10.1124/mol.111.077537] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Polyphenolic ellagitannins are natural compounds that are often associated with the therapeutic activity of plant extracts used in traditional medicine. They display cancer-preventing activity in animal models by a mechanism that remains unclear. Potential targets have been proposed, including DNA topoisomerases II (Top2). Top2α and Top2β, the two isoforms of the human Top2, play a crucial role in the regulation of replication, transcription, and chromosome segregation. They are the target of anticancer agents used in the clinic such as anthracyclines (e.g., doxorubicin) or the epipodophyllotoxin etoposide. It was recently shown that the antitumor activity of etoposide was due primarily to the inhibition of Top2α, whereas inhibition of Top2β was responsible for the development of secondary malignancies, pointing to the need for more selective Top2α inhibitors. Here, we show that the polyphenolic ellagitannin vescalagin preferentially inhibits the decatenation activity of Top2α in vitro, by a redox-independent mechanism. In CEM cells, we also show that transient small interfering RNA-mediated down-regulation of Top2α but not of Top2β conferred a resistance to vescalagin, indicating that the α isoform is a preferential target. We further confirmed that Top2α inhibition was due to a catalytic inhibition of the enzyme because it did not induce DNA double-strand breaks in CEM-treated cells but prevented the formation of Top2α- rather than Top2β-DNA covalent complexes induced by etoposide. To our knowledge, vescalagin is the first example of a catalytic inhibitor for which cytotoxicity is due, at least in part, to the preferential inhibition of Top2α.
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Affiliation(s)
- Céline Auzanneau
- Institut National de la Santé et de la Recherche Médicale U916 and Université de Bordeaux, Institut Bergonié, Bordeaux, France
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207
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Guchhait SK, Chandgude AL, Priyadarshani G. CuSO4-glucose for in situ generation of controlled Cu(I)-Cu(II) bicatalysts: multicomponent reaction of heterocyclic azine and aldehyde with alkyne, and cycloisomerization toward synthesis of N-fused imidazoles. J Org Chem 2012; 77:4438-44. [PMID: 22486279 DOI: 10.1021/jo3003024] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The catalytic efficiency of mixed Cu(I)-Cu(II) system in situ generated by partial reduction of CuSO(4) with glucose in ethanol (nonanhydrous) under open air has been explored. With this catalysis, the multicomponent cascade reaction of A(3)-coupling of heterocyclic amidine with aldehyde and alkyne, 5-exo-dig cycloisomerization, and prototropic shift has afforded an efficient and eco-friendly synthesis of therapeutically important versatile N-fused imidazoles. Diverse heterocyclic amidines, several of which are known to be poorly reactive, and aldehydes are compatible in this catalytic process.
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Affiliation(s)
- Sankar K Guchhait
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, S. A. S. Nagar (Mohali), 160062, Punjab, India.
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208
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Scaffold hybridization in generation of indenoindolones as anticancer agents that induce apoptosis with cell cycle arrest at G2/M phase. Bioorg Med Chem Lett 2012; 22:2474-9. [DOI: 10.1016/j.bmcl.2012.02.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/16/2012] [Accepted: 02/03/2012] [Indexed: 11/20/2022]
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209
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Bailly C. Contemporary challenges in the design of topoisomerase II inhibitors for cancer chemotherapy. Chem Rev 2012; 112:3611-40. [PMID: 22397403 DOI: 10.1021/cr200325f] [Citation(s) in RCA: 213] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Christian Bailly
- Centre de Recherche et Développement, Institut de Recherche Pierre Fabre, Toulouse, France.
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210
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Guchhait SK, Chaudhary V, Madaan C. A chemoselective Ugi-type reaction in water using TMSCN as a functional isonitrile equivalent: generation of heteroaromatic molecular diversity. Org Biomol Chem 2012; 10:9271-7. [DOI: 10.1039/c2ob26733k] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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211
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Molecular characterization of EP6—A novel imidazo[1,2-a]pyridine based direct 5-lipoxygenase inhibitor. Biochem Pharmacol 2012; 83:228-40. [DOI: 10.1016/j.bcp.2011.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 10/10/2011] [Accepted: 10/11/2011] [Indexed: 01/18/2023]
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212
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Saima Y, Khamarui S, Gayen KS, Pandit P, Maiti DK. Efficient catalytic cyclizations of three and two imine assemblies: direct access to tetrahydroimidazo[1,5-c]imidazol-7-ones and imidazoles. Chem Commun (Camb) 2012; 48:6601-3. [DOI: 10.1039/c2cc32760k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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213
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Nordqvist A, Nilsson MT, Lagerlund O, Muthas D, Gising J, Yahiaoui S, Odell LR, Srinivasa BR, Larhed M, Mowbray SL, Karlén A. Synthesis, biological evaluation and X-ray crystallographic studies of imidazo[1,2-a]pyridine-based Mycobacterium tuberculosis glutamine synthetase inhibitors. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md00310d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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