The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
Helmut Hartung - One of the best experts on this subject based on the ideXlab platform.
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a facile synthesis of substituted 1 4 benzothiazepin 5 4h ones and pyrido 3 2 f 1 4 thiazepin 5 4h ones crystal and molecular structure of 2 ethylthio 4 methyl 5 4h oxopyrido 3 2 f 1 4 thiazepine 3 carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
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A Facile Synthesis of Substituted 1,4‐Benzothiazepin‐5(4H)‐ones and Pyrido[3,2‐f][1,4]thiazepin‐5(4H)‐ones − Crystal and Molecular Structure of 2‐Ethylthio‐4‐methyl‐5(4H)‐oxopyrido[3,2‐f][1,4]thiazepine‐3‐carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
Alexander V. Nemukhin - One of the best experts on this subject based on the ideXlab platform.
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Quantum chemical modeling of the reduction of cis‐diammineplatinum(IV) tetrachloride [Pt(NH3)2Cl4] by methyl Thiolate Anion
Journal of computational chemistry, 2005Co-Authors: Ia. I. Dobrogorskaia-méreau, Alexander V. NemukhinAbstract:We present here both an ab initio and quantum mechanical/molecular mechanical (QM/MM) study of the cis-[Pt(NH3)2Cl4] complex reduction by methyl Thiolate Anion, SCH(-3), which is used as a model of glutathione. Geometry and electronic structure of cis-[Pt(NH3)2Cl4] are determined without and in aqueous medium. The mechanism of the reaction of reduction is characterized. The calculated activation energy of the reaction compares remarkably well with the experimental value.
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quantum chemical modeling of the reduction of cis diammineplatinum iv tetrachloride pt nh3 2cl4 by methyl Thiolate Anion
Journal of Computational Chemistry, 2005Co-Authors: Ia I Dobrogorskaiamereau, Alexander V. NemukhinAbstract:We present here both an ab initio and quantum mechanical/molecular mechanical (QM/MM) study of the cis-[Pt(NH3)2Cl4] complex reduction by methyl Thiolate Anion, SCH(-3), which is used as a model of glutathione. Geometry and electronic structure of cis-[Pt(NH3)2Cl4] are determined without and in aqueous medium. The mechanism of the reaction of reduction is characterized. The calculated activation energy of the reaction compares remarkably well with the experimental value.
Wolfgang Dölling - One of the best experts on this subject based on the ideXlab platform.
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a facile synthesis of substituted 1 4 benzothiazepin 5 4h ones and pyrido 3 2 f 1 4 thiazepin 5 4h ones crystal and molecular structure of 2 ethylthio 4 methyl 5 4h oxopyrido 3 2 f 1 4 thiazepine 3 carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
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A Facile Synthesis of Substituted 1,4‐Benzothiazepin‐5(4H)‐ones and Pyrido[3,2‐f][1,4]thiazepin‐5(4H)‐ones − Crystal and Molecular Structure of 2‐Ethylthio‐4‐methyl‐5(4H)‐oxopyrido[3,2‐f][1,4]thiazepine‐3‐carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
M. Biedermann - One of the best experts on this subject based on the ideXlab platform.
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a facile synthesis of substituted 1 4 benzothiazepin 5 4h ones and pyrido 3 2 f 1 4 thiazepin 5 4h ones crystal and molecular structure of 2 ethylthio 4 methyl 5 4h oxopyrido 3 2 f 1 4 thiazepine 3 carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
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A Facile Synthesis of Substituted 1,4‐Benzothiazepin‐5(4H)‐ones and Pyrido[3,2‐f][1,4]thiazepin‐5(4H)‐ones − Crystal and Molecular Structure of 2‐Ethylthio‐4‐methyl‐5(4H)‐oxopyrido[3,2‐f][1,4]thiazepine‐3‐carbonitrile
European Journal of Organic Chemistry, 1998Co-Authors: Wolfgang Dölling, M. Biedermann, Helmut HartungAbstract:A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as Thiolate Anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.
Ralf Morgenstern - One of the best experts on this subject based on the ideXlab platform.
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pre steady state kinetic characterization of Thiolate Anion formation in human leukotriene c synthase
Biochemistry, 2012Co-Authors: Agnes Rinaldomatthis, Ralf Morgenstern, Shabbir Ahmad, Anders Wetterholm, P J Lachmann, Jesper Z HaeggstromAbstract:Human leukotriene C4 synthase (hLTC4S) is an integral membrane protein that catalyzes the committed step in the biosynthesis of cysteinyl-leukotrienes, i.e., formation of leukotriene C4 (LTC4). Thi...
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Kinetic characterization of Thiolate Anion formation and chemical catalysis of activated microsomal glutathione transferase 1.
Biochemistry, 2004Co-Authors: Richard Svensson, Johan Ålander, Richard N. Armstrong, Ralf MorgensternAbstract:Microsomal glutathione transferase 1 (MGST1) displays the unique ability to be activated, up to 30-fold, by the reaction with sulfhydryl reagents, e.g., N-ethylmaleimide. Analysis of glutathione (GSH) Thiolate formation, which occurs upon mixing activated MGST1 with GSH, reveals biphasic kinetics, where the rapid phase dominated at higher GSH concentrations. The kinetic behavior suggests a two-step mechanism consisting of a rapid GSH-binding step (KDGSH ≈ 10 mM), followed by slower formation of Thiolate (k2 ≈ 10 s-1). The release rate (or protonation of the enzyme GSH Thiolate complex) of GS- was slow (k-2 = 0.016 s-1), consistent with overall tight binding of GSH. Electrophilic second substrates react rapidly with the E•GS- complex, and again, a two-step mechanism is suggested. In comparison to the unactivated enzyme [Morgenstern et al. (2001) Biochemistry 40, 3378−3384], the mechanisms of GSH Thiolate formation and electrophile interaction are similar; however, Thiolate Anion formation is enhanced 30-fo...
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Kinetic analysis of the slow ionization of glutathione by microsomal glutathione transferase MGST1.
Biochemistry, 2001Co-Authors: Ralf Morgenstern, Richard Svensson, Bryan A. Bernat, Richard N. ArmstrongAbstract:An important aspect of the catalytic mechanism of microsomal glutathione transferase (MGST1) is the activation of the thiol of bound glutathione (GSH). GSH binding to MGST1 as measured by Thiolate Anion formation, proton release, and Meisenheimer complex formation is a slow process that can be described by a rapid binding step ( = 47 ± 7 mM) of the peptide followed by slow deprotonation (k2 = 0.42 ± 0.03 s-1). Release of the GSH Thiolate Anion is very slow (apparent first-order rate k-2 = 0.0006 ± 0.00002 s-1) and thus explains the overall tight binding of GSH. It has been known for some time that the turnover (kcat) of MGST1 does not correlate well with the chemical reactivity of the electrophilic substrate. The steady-state kinetic parameters determined for GSH and 1-chloro-2,4-dinitrobenzene (CDNB) are consistent with Thiolate Anion formation (k2) being largely rate-determining in enzyme turnover (kcat = 0.26 ± 0.07 s-1). Thus, the chemical step of Thiolate addition is not rate-limiting and can be stud...
