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Greenshields MWCC, Hümmelgen IA, Mamo MA, Shaikjee A, Mhlanga SD, van Otterlo WAL, Coville NJ. Composites of polyvinyl alcohol and carbon (coils, undoped and nitrogen doped multiwalled carbon nanotubes) as ethanol, methanol and toluene vapor sensors. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2011; 11:10211-10218. [PMID: 22413367 DOI: 10.1166/jnn.2011.4991] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigate the chemical sensing behavior of composites prepared with polyvinyl alcohol and carbon materials (undoped multiwalled carbon nanotubes, nitrogen-doped multiwalled carbon nanotubes and carbon nanocoils). We determine the sensitivity of thin films of these composites for ethanol, methanol and toluene vapor, comparing their conductance and capacitance responses. The composite that exhibits highest sensitivity depends on specific vapor, vapor concentration and measured electrical response, showing that the interactivity of the carbon structure with chemical species depend on structural specificities of the carbon structure and doping.
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Magedov IV, Frolova L, Manpadi M, Bhoga UD, Tang H, Evdokimov NM, George O, Georgiou KH, Renner S, Getlik M, Kinnibrugh TL, Fernandes MA, Van slambrouck S, Steelant WFA, Shuster CB, Rogelj S, van Otterlo WAL, Kornienko A. Anticancer properties of an important drug lead podophyllotoxin can be efficiently mimicked by diverse heterocyclic scaffolds accessible via one-step synthesis. J Med Chem 2011; 54:4234-46. [PMID: 21615090 DOI: 10.1021/jm200410r] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structural simplification of an antimitotic natural product podophyllotoxin with mimetic heterocyclic scaffolds constructed using multicomponent reactions led to the identification of compounds exhibiting low nanomolar antiproliferative and apoptosis-inducing properties. The most potent compounds were found in the dihydropyridopyrazole, dihydropyridonaphthalene, dihydropyridoindole, and dihydropyridopyrimidine scaffold series. Biochemical mechanistic studies performed with dihydropyridopyrazole compounds showed that these heterocycles inhibit in vitro tubulin polymerization and disrupt the formation of mitotic spindles in dividing cells at low nanomolar concentrations, in a manner similar to podophyllotoxin itself. Separation of a racemic dihydropyridonaphthalene into individual enantiomers demonstrated that only the optical antipode matching the absolute configuration of podophyllotoxin possessed potent anticancer activity. Computer modeling, performed using the podophyllotoxin binding site on β-tubulin, provided a theoretical understanding of these successful experimental findings.
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Möcklinghoff S, van Otterlo WAL, Rose R, Fuchs S, Zimmermann TJ, Dominguez Seoane M, Waldmann H, Ottmann C, Brunsveld L. Design and evaluation of fragment-like estrogen receptor tetrahydroisoquinoline ligands from a scaffold-detection approach. J Med Chem 2011; 54:2005-11. [PMID: 21381753 DOI: 10.1021/jm1011116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A library of small tetrahydroisoquinoline ligands, previously identified via structure- and chemistry-based hierarchical organization of library scaffolds in tree-like arrangements, has been generated as novel estrogen receptor agonistic fragments via traditional medicinal chemistry exploration. The approach described has allowed for the rapid evaluation of a structure-activity relationship of the ligands concerning estrogen receptor affinity and estrogen receptor β subtype selectivity. The structural biological insights obtained from the fragments aid the understanding of larger analogues and constitute attractive starting points for further optimization.
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Klüter S, Simard JR, Rode HB, Grütter C, Pawar V, Raaijmakers HCA, Barf TA, Rabiller M, van Otterlo WAL, Rauh D. Inside Cover: Characterization of Irreversible Kinase Inhibitors by Directly Detecting Covalent Bond Formation: A Tool for Dissecting Kinase Drug Resistance (ChemBioChem 18/2010). Chembiochem 2010. [DOI: 10.1002/cbic.201090088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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55
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Johnson MM, Naidoo JM, Fernandes MA, Mmutlane EM, van Otterlo WAL, de Koning CB. CAN-Mediated Oxidations for the Synthesis of Xanthones and Related Products. J Org Chem 2010; 75:8701-4. [DOI: 10.1021/jo101873v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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56
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Klüter S, Simard JR, Rode HB, Grütter C, Pawar V, Raaijmakers HCA, Barf TA, Rabiller M, van Otterlo WAL, Rauh D. Characterization of Irreversible Kinase Inhibitors by Directly Detecting Covalent Bond Formation: A Tool for Dissecting Kinase Drug Resistance. Chembiochem 2010; 11:2557-66. [DOI: 10.1002/cbic.201000352] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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57
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Pawar VG, Sos ML, Rode HB, Rabiller M, Heynck S, van Otterlo WAL, Thomas RK, Rauh D. Synthesis and biological evaluation of 4-anilinoquinolines as potent inhibitors of epidermal growth factor receptor. J Med Chem 2010; 53:2892-901. [PMID: 20222733 DOI: 10.1021/jm901877j] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mutant receptor tyrosine kinase EGFR is a validated and therapeutically amenable target for genotypically selected lung cancer patients. Here we present the synthesis and biological evaluation of a series of 6- and 7-substituted 4-anilinoquinolines as potent type I inhibitors of clinically relevant mutant variants of EGFR. Quinolines 3a and 3e were found to be highly active kinase inhibitors in biochemical assays and were further investigated for their biological effect on EGFR-dependent Ba/F3 cells and non-small cell lung cancer (NSCLC) cell lines.
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Manpadi M, Kireev AS, Magedov IV, Altig J, Tongwa P, Antipin MY, Evidente A, van Otterlo WAL, Kornienko A. Synthesis of structurally simplified analogues of pancratistatin: truncation of the cyclitol ring. J Org Chem 2010; 74:7122-31. [PMID: 19743883 DOI: 10.1021/jo901494r] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pancratistatin is a phenanthridone-type natural product isolated from several plants of the Amaryllidaceae family. Its potent antiproliferative, antivascular, antiviral, and antiparasitic properties have attracted the attention of synthetic, biological, and medicinal chemists. Pancratistatin's low natural availability and complex structure have steered many of these research projects toward the preparation of its simplified synthetic analogues with useful levels of activity. In this work we have developed synthetic chemistry aimed at the preparation of pancratistatin analogues with a truncated cyclitol portion of the molecule. The described synthetic pathways are based on a highly anti-diastereoselective arylcuprate conjugate addition to gamma-alkoxy-alpha,beta-enoates and syn-selective azidation at the alpha-position of ester enolates. Analogues with the formally cleaved C3-C4 bond, and thus containing an open ring C, as well as a compound containing a truncated lactol moiety in lieu of the cyclitol, were prepared. Several of the analogues exhibited weak antiproliferative activity, with the highest potency observed in the case of the lactol analogue. From these results implications for the design of future pancratistatin analogues are discussed. Furthermore, the synthetic pathways can be used to construct pancratistatin-mimetic libraries, in which the cyclitol moiety is replaced by other cyclic motifs.
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van Otterlo WAL, de Koning CB. Metathesis in the synthesis of aromatic compounds. Chem Rev 2009; 109:3743-82. [PMID: 19618929 DOI: 10.1021/cr900178p] [Citation(s) in RCA: 247] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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60
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Renner S, van Otterlo WAL, Dominguez Seoane M, Möcklinghoff S, Hofmann B, Wetzel S, Schuffenhauer A, Ertl P, Oprea TI, Steinhilber D, Brunsveld L, Rauh D, Waldmann H. Bioactivity-guided mapping and navigation of chemical space. Nat Chem Biol 2009; 5:585-92. [PMID: 19561619 DOI: 10.1038/nchembio.188] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 04/22/2009] [Indexed: 11/09/2022]
Abstract
The structure- and chemistry-based hierarchical organization of library scaffolds in tree-like arrangements provides a valid, intuitive means to map and navigate chemical space. We demonstrate that scaffold trees built using bioactivity as the key selection criterion for structural simplification during tree construction allow efficient and intuitive mapping, visualization and navigation of the chemical space defined by a given library, which in turn allows correlation of this chemical space with the investigated bioactivity and further compound design. Brachiation along the branches of such trees from structurally complex to simple scaffolds with retained yet varying bioactivity is feasible at high frequency for the five major pharmaceutically relevant target classes and allows for the identification of new inhibitor types for a given target. We provide proof of principle by identifying new active scaffolds for 5-lipoxygenase and the estrogen receptor ERalpha.
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Pathak R, Naicker P, Thompson WA, Fernandes MA, de Koning CB, van Otterlo WAL. Intramolecular Hydroaminations Mediated by Reductive Mercuration orn-Butyllithium To Afford 3-Methyl- and 3,4-Dimethyl-1,2,3,4-tetrahydroisoquinolines. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700580] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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van Otterlo WAL, Michael JP, de Koning CB. Alternatives to N,N‐Diethyl‐2,4‐dimethoxybenzamide as a Precursor for the Synthesis of 6,8‐Dimethoxy‐3‐methyl‐3,4‐dihydro‐1H‐isochromen‐1‐one. SYNTHETIC COMMUN 2007. [DOI: 10.1080/00397910701557655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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63
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Panayides JL, Pathak R, de Koning CB, van Otterlo WAL. Synthesis of Substituted 2,3-Dihydro-1H-2-benzazepines and 1,2-Dihydroisoquinolines Using an Isomerization-Ring-Closing Metathesis Strategy: Scope and Limitations. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700473] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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64
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Govender S, Mmutlane EM, van Otterlo WAL, de Koning CB. Bidirectional racemic synthesis of the biologically active quinone cardinalin 3. Org Biomol Chem 2007; 5:2433-40. [PMID: 17637963 DOI: 10.1039/b707187f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Readily available 2,2',6,6'-tetramethoxy-1,1'-biphenyl was transformed in 14 synthetic steps into the natural product cardinalin 3 using a bidirectional approach. One of the key steps was the formation of the cis-1,3-dimethylnaphtho[2,3-c]pyran ring. (+/-)-1,1'-[6,6'-Diallyl-5,5'-bis(benzyloxy)-1,1',3,3'-tetramethoxy-2,2'-binaphthalene-7,7'-diyl]diethanol was treated with O(2) in the presence of CuCl(2) and catalytic PdCl(2) to afford 5,5'-bis(benzyloxy)-7,7',9,9'-tetramethoxy-1,1',3,3'-tetramethyl-1H,1'H-8,8'-bibenzo[g]isochromene. Hydrogenation of this compound afforded 7,7',9,9'-tetramethoxy-cis-1,3-cis-1',3'-tetramethyl-3,3',4,4'-tetrahydro-1H,1'H-8,8'-bibenzo[g]isochromene-5,5'-diol in quantitative yield, which was converted in 3 steps to cardinalin 3.
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Hanessian S, Therrien E, van Otterlo WAL, Bayrakdarian M, Nilsson I, Fjellström O, Xue Y. Phenolic P2/P3 core motif as thrombin inhibitors—Design, synthesis, and X-ray co-crystal structure. Bioorg Med Chem Lett 2006; 16:1032-6. [PMID: 16290930 DOI: 10.1016/j.bmcl.2005.10.082] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 10/14/2005] [Accepted: 10/24/2005] [Indexed: 10/25/2022]
Abstract
Prototypical thrombin inhibitors were synthesized based on a trisubstituted phenol as a core motif. A naphthylsulfonamide analogue showed excellent antithrombin activity. An X-ray co-crystal structure showed the expected interactions.
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Pelly SC, Parkinson CJ, van Otterlo WAL, de Koning CB. Metathesis Reactions for the Synthesis of Ring-Fused Carbazoles. J Org Chem 2005; 70:10474-81. [PMID: 16323860 DOI: 10.1021/jo051826s] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reactions: see text] The metathesis reaction is used as a key step for the synthesis of the indolo[2,3-a]carbazole core of rebeccamycin 13 and the sulfur analog of furostifoline 21. Using the same methodology for the attempted synthesis of furostifoline, we unexpectedly formed tert-butyl-2a-methyl-1,2,2a,10c-tetrahydro-6H-cyclobuta[c]furo[3,2-a]carbazole-6-carboxylate 26 from the unstable diene, tert-butyl 2-(2-isopropenyl-3-furyl)-3-vinyl-1H-indole-1-carboxylate 25, presumably via a spontaneous pi8 electrocyclization reaction.
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Pathak R, Vandayar K, van Otterlo WAL, Michael JP, Fernandes MA, de Koning CB. The synthesis of angularly fused polyaromatic compounds by using a light-assisted, base-mediated cyclization reaction. Org Biomol Chem 2004; 2:3504-9. [PMID: 15565244 DOI: 10.1039/b412932f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of substituted polyaromatic compounds that contain at least four benzene rings fused together in an angular fashion is described. Suzuki coupling of 1-bromo-3,4-dihydronaphthalene-2-carbaldehyde with a number of aromatic boronic acids affords products such as 1-(1,4-dimethoxy-3-methyl-2-naphthyl)-3,4-dihydronaphthalene-2-carbaldehyde. Exposure of these dihydronaphthalenes to potassium tert-butoxide and DMF at 80 degrees C yields polyaromatic compounds such as 9,14-dimethoxynaphtho[1,2-a]anthracene.
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de Koning CB, Michael JP, van Otterlo WAL. Syntheses of isochromane analogues of the michellamines and korupensamines. ACTA ACUST UNITED AC 2000. [DOI: 10.1039/a908367g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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