49761-04-8Relevant articles and documents
Comparative study of selected coupling reagents in dipeptide synthesis
Dudash Jr.,Jiang,Mayer,Joullie
, p. 349 - 356 (2007/10/02)
A comparative study of the effectiveness of selected coupling reagents in dipeptide synthesis was conducted. Included in the study were a new coupling agent, pentafluorophenyl diphenylphosphinate (FDPP, 1), benzotriazol-1-yl-oxytris(dimethylamino)phosphon
Total Synthesis of Thymosin β4, 2. Conventional Synthesis of the Fragment of Thymosin β4
Kapurniotu, Afroditi,Voelter, Wolfgang
, p. 361 - 370 (2007/10/02)
As part of the total synthesis of thymosin β4 three synthetic pathways for the synthesis of the thymosin β4 fragment are described.The side-chain functions are protected by tert-butyl and the α-amino residues by Z groups.As temporary protection of the carboxyl function the phenyl ester is successfully used.Key Words: Thymosin β4, fragment /Thymus peptides/Amino acids/Protecting groups, phenyl esters of peptides as/Peptides
KINETICS OF THE ALKALINE HYDROLYSIS OF SEVERAL N-BENZYLOXYCARBONYLDIPEPTIDE METHYL AND ETHYL ESTERS
Hoogwater, D. A.,Peereboom, M.
, p. 5325 - 5332 (2007/10/02)
The reaction rates of the alkaline hydrolysis of synthesized N-protected dipeptide methyl and ethyl esters were studied systematically.From the kinetic data the energies of activation, the pre-exponential factors and the reference values at 40 deg C were calculated.The rate of hydrolysis shows to be strongly dependent on the C-terminal amino acid in the sequence Gly >> Ala/Met/Phe > Leu >> Val/Pro.Surprisingly the N-terminal amino acid also exerts an effect, but in a different sequence.N-Terminal Phe in particular shows a relative accelerating effect.Remarkable is the significantly faster ester hydrolysis of glycine containing dipeptide ethyl esters in ethanol/water compared to the corresponding methyl esters in methanol/water.
RATES OF PEPTIDE FORMATION INVOLVING IMINO ACID RESIDUES
Wante, Dirk P. M.,Anteunis, Marc J. O.
, p. 73 - 82 (2007/10/02)
The determination of the rates for peptide coupling in tetrahydrofuran between Z-Aaa-OPcp (Aaa = Ala, (NMe)Ala, Pro, Thz, Pip and (S)Pip) and H-Bbb-OMe (Bbb = (NMe)Ala, Pro, Thz, Pip and (S)Pip) allowed us to evaluate the relative reactivities between these members, either as active components or as amino components.The reactivity of Pro (either as the active species or the amino component) equals that of (NMe)Ala.The reactivity of Pip and (S)Pip as imino components is low while the activation energy is raised by an amount that roughly equals the energy increment needed for bringing the carboxylate grouping from the equatorial to the axial position The reactivities of these six-membered residues are also appreciably low when being the active components during peptide coupling.The presence of a ring-sulfur atom at γ-position of nitrogen additionally decreases the rate for peptidation, especially if (S)Pip is the imino component.
