The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Wilshire J. F. K. - One of the best experts on this subject based on the ideXlab platform.
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Studies in Thiohydantoin chemistry 1: some aspects of the Schlack-Kumpf reaction
CSIRO Publishing, 1996Co-Authors: Duggan B. M., Laslett R. L., Wilshire J. F. K.Abstract:An investigation has been carried out into the Schlack-Kumpf reaction, i.e., the reaction of amino acids with a mixture of acetic anhydride, acetic acid and sodium thiocyanate (occasionally ammonium thiocyanate was used). Particular emphasis was placed on the reactions with amino acids containing sensitive or functional side chains, i.e., serine, threonine, arginine, proline, lysine, histidine, cysteine, and aspartic and glutamic acids. The reaction of serine, and of certain of its O- and N-substituted Derivatives, takes an unusual course to give an acetylated Thiohydantoin Derivative of cysteine. Correspondingly, threonine gives an acetylated Thiohydantoin Derivative of beta-methylcysteine. Similar reactions occurred with the 3-phenylThiohydantoin Derivatives of serine and of threonine to give acetylated Thiohydantoin Derivatives of cysteine and of beta-methylcysteine respectively
Rob M J Liskamp - One of the best experts on this subject based on the ideXlab platform.
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sequencing of peptoid peptidomimetics by edman degradation
Tetrahedron Letters, 1998Co-Authors: Astrid Boeijen, Rob M J LiskampAbstract:The direct identification of resin-bound peptoid peptidomimetics by sequencing is described. The N-terminus of the peptoid was treated with phenyl isothiocyanate, after which the N-terminal peptoid residue was cleaved from the resin as its Thiohydantoin Derivative. For deduction of the peptoid sequence, the HPLC retention times of the obtained Thiohydantoins were compared to those of independently prepared reference Thiohydantoins.
Mp Kaushik - One of the best experts on this subject based on the ideXlab platform.
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Novel and efficient protocol for the syntheses of N-1 substituted Thiohydantoin and a bicycloThiohydantoin under solvent-free conditions
Elsevier Science, 2012Co-Authors: Kumar Vinod, Rana Hemlata, Sankolli Ravish, Mp KaushikAbstract:A novel approach for the synthesis of N-1 substituted Thiohydantoin has been developed to give quantitative yields of the desired products. The efficient synthesis of bis-Thiohydantoin Derivative and bicycloThiohydantoin has extended scope and applicability of present method. Solvent-free conditions and very easy work-up procedure make the reaction convenient and eco-friendly. All the products were characterized by spectroscopic techniques and elemental analysis, and finally the structure of representative ;compound was also confirmed by X-ray crystallography. (C) 2012 Elsevier Ltd. All rights reserved
Duggan B. M. - One of the best experts on this subject based on the ideXlab platform.
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Studies in Thiohydantoin chemistry 1: some aspects of the Schlack-Kumpf reaction
CSIRO Publishing, 1996Co-Authors: Duggan B. M., Laslett R. L., Wilshire J. F. K.Abstract:An investigation has been carried out into the Schlack-Kumpf reaction, i.e., the reaction of amino acids with a mixture of acetic anhydride, acetic acid and sodium thiocyanate (occasionally ammonium thiocyanate was used). Particular emphasis was placed on the reactions with amino acids containing sensitive or functional side chains, i.e., serine, threonine, arginine, proline, lysine, histidine, cysteine, and aspartic and glutamic acids. The reaction of serine, and of certain of its O- and N-substituted Derivatives, takes an unusual course to give an acetylated Thiohydantoin Derivative of cysteine. Correspondingly, threonine gives an acetylated Thiohydantoin Derivative of beta-methylcysteine. Similar reactions occurred with the 3-phenylThiohydantoin Derivatives of serine and of threonine to give acetylated Thiohydantoin Derivatives of cysteine and of beta-methylcysteine respectively
John E. Shively - One of the best experts on this subject based on the ideXlab platform.
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Automated carboxy-terminal sequence analysis of peptides.
Protein science : a publication of the Protein Society, 1992Co-Authors: Jerome M. Bailey, Narmada R. Shenoy, Michael Ronk, John E. ShivelyAbstract:Proteins and peptides can be sequenced from the carboxy-terminus with isothiocyanate reagents to produce amino acid Thiohydantoin Derivatives. Previous studies in our laboratory have focused on solution phase conditions for formation of the peptidylThiohydantoins with trimethylsilylisothiocyanate (TMS-ITC) and for hydrolysis of these peptidylThiohydantoins into an amino acid Thiohydantoin Derivative and a new shortened peptide capable of continued degradation (Bailey, J. M. & Shively, J. E., 1990, Biochemistry 29, 3145-3156). The current study is a continuation of this work and describes the construction of an instrument for automated C-terminal sequencing, the application of the thiocyanate chemistry to peptides covalently coupled to a novel polyethylene solid support (Shenoy, N. R., Bailey, J. M., & Shively, J. E., 1992, Protein Sci. I, 58-67), the use of sodium trimethylsilanolate as a novel reagent for the specific cleavage of the derivatized C-terminal amino acid, and the development of methodology to sequence through the difficult amino acid, aspartate. Automated programs are described for the C-terminal sequencing of peptides covalently attached to carboxylic acid-modified polyethylene. The chemistry involves activation with acetic anhydride, derivatization with TMS-ITC, and cleavage of the derivatized C-terminal amino acid with sodium trimethylsilanolate. The Thiohydantoin amino acid is identified by on-line high performance liquid chromatography using a Phenomenex Ultracarb 5 ODS(30) column and a triethylamine/phosphoric acid buffer system containing pentanesulfonic acid. The generality of our automated C-terminal sequencing methodology was examined by sequencing model peptides containing all 20 of the common amino acids. All of the amino acids were found to sequence in high yield (90% or greater) except for asparagine and aspartate, which could be only partially removed, and proline, which was found not be capable of derivatization. In spite of these current limitations, the methodology should be a valuable new tool for the C-terminal sequence analysis of peptides.