The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
P.g. Williams - One of the best experts on this subject based on the ideXlab platform.
-
Structure and dynamics of Tosylchymotrypsin at pH 7 examined by tritium NMR spectroscopy
Biochimica et biophysica acta, 1994Co-Authors: Thomas M. O'connell, J.t. Gerig, P.g. WilliamsAbstract:3H-NMR spectroscopy of specifically tritiated and tritiated/deuterated derivatives of Tosylchymotrypsin has been used to examine the behavior of the Tosyl Group in this protein at pH 7. The presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of T1 relaxation, line widths, and various nuclear Overhauser experiments for the collection of tritiated species present in the samples were used to the interpret the observations made. These analyses suggests that the Tosyl Group of Tosylchymotrypsin at pH 7 is largely retained within the substrate specificity pocket observed in the crystal structure. This outcome is in strong contrast to the situation observed at pH 4, where the Tosyl Group is mobile enough to be found outside the specificity pocket an appreciable fraction of the time, and may be the result of protein association at pH 7.
-
Probing protein structure and dynamics by tritium NMR
Journal of Labelled Compounds and Radiopharmaceuticals, 1993Co-Authors: Thomas M. O'connell, P.g. Williams, J.t. GerigAbstract:Tritium nmr spectroscopy of specifically tritiated Tosylchymotrypsin has been used to examine the properties of the Tosyl Group in this protein. The unavoidable presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of relaxation behavior of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the Tosyl Group of Tosylchymotrypsin at pH 4 is highly mobile in solution and occupies the lacation in the protein that is observed in the crystalline state only about 50% of the time.
-
Examination of the structure and dynamics of Tosylchymotrypsin at pH 4 by tritium NMR spectroscopy
Journal of the American Chemical Society, 1993Co-Authors: Thomas M. O'connell, J.t. Gerig, P.g. WilliamsAbstract:Tritium NMR spectroscopy of specifically tritiated and tritiated/deuterated derivatives of Tosylchymotrypsin has been used to examine the properties of the Tosyl Group in this protein. The presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of the composite relaxation behavior of the collection of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the Tosyl Group of Tosylchymotrypsin at pH 4 is highly mobile in solution and, on average, only occupies the location in the protein that is observed in the solid state about 50% of the time. 31 refs., 5 figs., 1 tab.
Rafik Rajjak Shaikh - One of the best experts on this subject based on the ideXlab platform.
-
A ‘Click’ Approachto the Synthesis of 3-[2-(1-Alkyltriazol-4-yl)ethyl]indoles
Synthesis, 2009Co-Authors: Marino Petrini, Rafik Rajjak ShaikhAbstract:Copper-catalyzed cycloaddition of N-(tert-butoxycarbonyl)-3-(1-Tosyl-3-butynyl)-1H-indole with various azides readily provides the corresponding (triazolylethyl)indoles. These derivatives can be regarded as indole-3-propionic acid mimics because of the electronic features of the triazole ring that are closely related to the amido Group. The obtained (indolylethyl)triazoles can be further functionalized exploiting an elimination―addition reaction involving the Tosyl Group.
-
Double functionalization of N-Boc-3-(Tosylmethyl)indole exploiting the activating properties of the Tosyl Group
Synlett, 2008Co-Authors: Alessandro Palmieri, Marino Petrini, Rafik Rajjak ShaikhAbstract:The anion prepared from N-Boc-3-(Tosylmethyl)indole using NaH in DMF can be readily functionalized by reaction with various electrophiles. The obtained sulfonyl indoles, upon removal of the N-protecting Group, undergo nucleophilic attack via a vinylogous imino derivative, leading to branched 3-substituted indoles.
Mysore S. Shashidhar - One of the best experts on this subject based on the ideXlab platform.
-
Conformational Polymorphism in Racemic 2,4-Di- o -Benzoyl-6- o -Tosyl myo -Inositol 1,3,5-Orthoacetate
Journal of Structural Chemistry, 2010Co-Authors: K. Manoj, Rajesh G. Gonnade, Mohan Bhadbhade, Mysore S. ShashidharAbstract:The title compound, C29H26O10S, yields two conformational polymorphs concomitantly from dichloromethane-methanol mixture; the major polymorph grows as plates (Form I, monoclinic, P21/n) and the minor polymorph grows as needles (Form II, triclinic, P-1). The two forms differ mainly in orientation of the Tosyl Group. In Form I, sulfonyl oxygen of the Tosyl Group makes intermolecular C −H…O interactions, whereas the same Group in Form II is involved in an intramolecular short dipolar S=O…C=O (sulfonyl-carbonyl) contact. The molecular organization and the influence of various weak non-covalent interactions that stabilize these conformers in the crystal lattices are discussed.
-
Isostructural molecular strings linked via conserved dipolar (ether) O⋯CO short contacts in conformational polymorphs of racemic 2,4-di-O-acetyl-6-O-Tosyl-myo-inositol 1,3,5-orthoesters
CrystEngComm, 2009Co-Authors: K. Manoj, Rajesh G. Gonnade, Mohan Bhadbhade, Mysore S. ShashidharAbstract:Conformational dimorphs of racemic 2,4-di-O-acetyl-6-O-Tosyl-myo-inositol 1,3,5-orthoformate and its orthoacetate analogue were characterized using single crystal X-ray diffraction, thermal analysis and hot-stage microscopy techniques. In these polymorphs, the Tosyl Group adopted different conformations due to the rotation about the O–S bond. A significant variation in the torsion angle for the Tosyl Group (∼56°) was observed for Form II crystal of the orthoformate derivative, which exhibited an intramolecular dipolar SO⋯CO (sulfonyl–carbonyl) short contact. An interesting feature in all conformational polymorphs is the formation of an isostructural string (despite the differences in the orientation of the Tosyl Group) linked via dipolar (ether) O⋯CO contacts, which is further stitched by other weak interactions to form different layers in their crystal lattice.
Thomas M. O'connell - One of the best experts on this subject based on the ideXlab platform.
-
Structure and dynamics of Tosylchymotrypsin at pH 7 examined by tritium NMR spectroscopy
Biochimica et biophysica acta, 1994Co-Authors: Thomas M. O'connell, J.t. Gerig, P.g. WilliamsAbstract:3H-NMR spectroscopy of specifically tritiated and tritiated/deuterated derivatives of Tosylchymotrypsin has been used to examine the behavior of the Tosyl Group in this protein at pH 7. The presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of T1 relaxation, line widths, and various nuclear Overhauser experiments for the collection of tritiated species present in the samples were used to the interpret the observations made. These analyses suggests that the Tosyl Group of Tosylchymotrypsin at pH 7 is largely retained within the substrate specificity pocket observed in the crystal structure. This outcome is in strong contrast to the situation observed at pH 4, where the Tosyl Group is mobile enough to be found outside the specificity pocket an appreciable fraction of the time, and may be the result of protein association at pH 7.
-
Probing protein structure and dynamics by tritium NMR
Journal of Labelled Compounds and Radiopharmaceuticals, 1993Co-Authors: Thomas M. O'connell, P.g. Williams, J.t. GerigAbstract:Tritium nmr spectroscopy of specifically tritiated Tosylchymotrypsin has been used to examine the properties of the Tosyl Group in this protein. The unavoidable presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of relaxation behavior of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the Tosyl Group of Tosylchymotrypsin at pH 4 is highly mobile in solution and occupies the lacation in the protein that is observed in the crystalline state only about 50% of the time.
-
Examination of the structure and dynamics of Tosylchymotrypsin at pH 4 by tritium NMR spectroscopy
Journal of the American Chemical Society, 1993Co-Authors: Thomas M. O'connell, J.t. Gerig, P.g. WilliamsAbstract:Tritium NMR spectroscopy of specifically tritiated and tritiated/deuterated derivatives of Tosylchymotrypsin has been used to examine the properties of the Tosyl Group in this protein. The presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of the composite relaxation behavior of the collection of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the Tosyl Group of Tosylchymotrypsin at pH 4 is highly mobile in solution and, on average, only occupies the location in the protein that is observed in the solid state about 50% of the time. 31 refs., 5 figs., 1 tab.
Li-xin Dai - One of the best experts on this subject based on the ideXlab platform.
-
Unexpected transfer of Tosyl Group of ArCH=NTs-catalyzed by N-heterocyclic carbene.
The Journal of organic chemistry, 2008Co-Authors: Dong-dong Chen, Xue-long Hou, Li-xin DaiAbstract:Reactions of N-Tosylimines with aziridines and electron-deficient unsaturated compounds in the presence of catalytic amount of NHC afforded unexpected Tosyl Group transfer products in good to high yields, which represent a new reaction pattern for imines as well as for catalysis of NHC.
-
unexpected transfer of Tosyl Group of arch nts catalyzed by n heterocyclic carbene
Journal of Organic Chemistry, 2008Co-Authors: Dong-dong Chen, Xue-long Hou, Li-xin DaiAbstract:Reactions of N-Tosylimines with aziridines and electron-deficient unsaturated compounds in the presence of catalytic amount of NHC afforded unexpected Tosyl Group transfer products in good to high yields, which represent a new reaction pattern for imines as well as for catalysis of NHC.