Search results for "peptide synthesis"

Synthesis of cyclic dipeptide templates, their incorporation into peptides and studies on their conformational and biological properties.

2009

This study investigated the diastereoselective synthesis of three dipeptide templates 1, 2 and 3, which may be regarded as conformationally restricted analogs of H-Gly-Xaa-OH, in which Xaa constitutes an aromatic amino acid. Bond formation between α-C of Gly and the aromatic moiety was achieved by proton-catalyzed intramolecular electrophilic aromatic substitution. The absolute configuration of the dipeptide templates was determined by single-crystal X-ray crystallography or by nuclear Overhauser enhancement measurements. A protective group strategy was elaborated to allow their incorporation into peptide sequences by liquid phase as well as by solid-phase peptide synthesis. The templates w…

Solid-Phase Synthesis of Biologically Important Glycopeptides

2003

Die 2-(Triphenylphosphonio)isopropyloxycarbonyl-(Ppoc-)-Gruppe und am Phosphoniumzentrum modizifierte analoge Reste als Aminoschutzgruppen bei der Pe…

1985

Die Einfuhrung in Aminosauren, die Stabilitat bei Peptidsynthesen und die selektive Abspaltung der 2-(Triphenylphosphonio)isopropyloxycarbonyl-(Ppoc-)-Aminoschutzgruppe sowie ihrer Varianten mit (Methyl)(diphenyl)phosphonium- und (Dimethyl)(phenyl)phosphoniumkopfen werden beschrieben. Der Ppoc-Rest ist in etwa um den Faktor 4 basenstabiler als der entsprechende 2-(Triphenylphosphonio)ethoxycarbonyl-(Peoc-)Rest. Er kann dennoch bereits bei pH = 8 in wasrig-methanolischer Hydrogencarbonatlosung von der blockierten Aminofunktion abgelost werden. Im Gegensatz zur Peoc-Abspaltung treten dabei keine storenden Nebenreaktionen des entstehenden Propenylphosphoniumsalzes mit der freigesetzten Aminofu…

A Versatile Grafting-to Approach for the Bioconjugation of Polymers to Collagen-like Peptides Using an Activated Ester Chain Transfer Agent

2009

DepartmentofMaterials Science and Engineering, University of Delaware, 201DuPont Hall, Newark, Delaware 19716,Received February 24, 2009Revised Manuscript Received April 24, 2009Biohybrid materials consisting of synthetic polymers andbiological moieties have gained more and more interest in therecent years.

ChemInform Abstract: Modified Trityl Ester Protecting Groups in Peptide Synthesis.

2010

Convenient High Yielding Gram Scale Solution Synthesis of Methionine-Enkephalin.

1998

A simple, large-scale synthesis of a cytokine, methionine-enkephalin, Tyr-Gly-Gly-Phe-Met, has been elaborated. Classical solution peptide chemistry methods without protection of amino acid side-chain functions and 1+(2+2) segment condensation were used. A nine-step synthesis from commercial amino acid derivatives was developed with yields ranging from 86% to 99%, averaging 92%. The purity of all intermediates was found to be 99.0-100% by HPLC. The process has been used to prepare greater than 150 g quantities of the pentapeptide as a monohydrate of 100% purity. Hydantoin formation was observed during saponification of Boc-Tyr-Gly-Gly-Phe-Met-OMe and minimised.

Addressing substrate glutamine requirements for tissue transglutaminase using substance P analogues

1999

AbstractWe have investigated the effect on the substrate requirements for guinea pig liver (tissue) transglutaminase of a set of 11 synthetic glutamine substitution analogues making up the full sequence of the naturally occurring tissue transglutaminase substrate substance P. While a number of peptide sequences derived from proteins that are well-recognized as tissue transglutaminase substrates have been studied, the enzyme activity using substitution analogues of full-length natural substrates has not been investigated as thoroughly. Thus, our set of substance P analogues only differs from one to other by one amino acid mutation while the length (of the peptide) is maintained as in the nat…

Hierarchical Imprinting Using Crude Solid Phase Peptide Synthesis Products as Templates

2003

The crude products resulting from solid-phase peptide synthesis can be used as epitope templates to generate surface-confined sites for the template and larger peptides containing the template motif. This offers a facile route to robust affinity stationary phases for the chromatographic separation of peptides.

Der 2-(4-pyridyl)Ethoxycarbonyl-(4-Pyoc)-rest - eine hydrophile, säure- und basenstabile aminoschutzgruppe für die peptidsynthese

1984

Abstract The title amino blocking function is stable under basic and acidic conditions frequently used in the peptide synthesis. Its hydrophilicity permits an effective peptide synthesis in water. After the easy conversion to the pyridinium form the 4-Pyoc group can be removed by morpholine.

Bis- and Trisamides Derived From 1′-Aminoferrocene-1-carboxylic Acid and α-Amino Acids: Synthesis and Conformational Analysis

2009

Ferrocene derivatives with one or two achiral and chiral arms based on α-amino acids (Gly, l-Ala, l-Val) attached to the cyclopentadienyl rings were prepared by solution-phase peptide synthesis from N-acetyl- and N-Boc-protected 1′-aminoferrocene-1-carboxylic acids (Boc = tert-butoxycarbonyl). The conformational preference in the solid state of selected examples was elucidated by X-ray crystallography. The chiroptical properties of chiral bis- and trisamides were investigated by circular dichroism (CD) spectroscopy in solution. The conformational preference was studied by NMR and IR spectroscopy, as well as by molecular modeling (DFT). For the bisamides, a conformational library is observed…