61058-42-2Relevant academic research and scientific papers
Organocatalyzed Asymmetric Aldol Reaction of α-Keto Amides with A Tripeptide Catalyst
Kon, Kazumasa,Takai, Hiromu,Kobayashi, Takumu,Kohari, Yoshihito,Murata, Miki
supporting information, p. 829 - 832 (2021/02/26)
An organocatalyzed asymmetric aldol reaction of α-keto amides was developed. An N-terminal 4- trans -siloxyproline-based tripeptide with an l - tert -leucine unit adjacent to the 4- trans -siloxyproline residue was used to catalyze the reaction between various α-keto amides and acetone, to produce the corresponding aldol adducts with up to 99% yield and 91% ee.
Unnatural tripeptide as highly enantioselective organocatalyst for asymmetric aldol reaction of isatins
Kon, Kazumasa,Kohari, Yoshihito,Murata, Miki
supporting information, p. 415 - 418 (2019/01/05)
The development of unnatural tripeptides as highly enantioselective organocatalysts for the asymmetric aldol reaction of isatins was achieved. H-Pro-Gly-D-Ala-OH with the D-alanine residue as the C-terminal amino acid residue expressed the best enantioselectivity. The H-Pro-Gly-D-Ala-OH-catalyzed reaction of isatins gave various aldol adducts with up to 93% yield and up to 97% ee. Investigation of the transition state via DFT calculation revealed that high optical purity was realized by the D-alanine controlled steric environment.
Borinic acid catalysed peptide synthesis
El Dine, Tharwat Mohy,Rouden, Jacques,Blanchet, Jér?me
supporting information, p. 16084 - 16087 (2015/11/10)
The catalytic synthesis of peptides is a major challenge in the modern organic chemistry hindered by the well-established use of stoichiometric coupling reagents. Herein, we describe for the first time that borinic acid is able to catalyse this reaction under mild conditions with an improved activity compared to our recently developed thiophene-based boronic acid. This catalyst is particularly efficient for peptide bond synthesis affording dipeptides in good yields without detectable racemization.
One-step C-terminal deprotection and activation of peptides with peptide amidase from stenotrophomonas maltophilia in neat organic solvent
Arif, Muhammad I.,Toplak, Ana,Szymanski, Wiktor,Feringa, Ben L.,Nuijens, Timo,Quaedflieg, Peter J. L. M.,Wu, Bian,Janssen, Dick B.
, p. 2197 - 2202 (2014/07/21)
Chemoenzymatic peptide synthesis is a rapidly developing technology for cost effective peptide production on a large scale. As an alternative to the traditional C→N strategy, which employs expensive N-protected building blocks in each step, we have investigated an N→C extension route that is based on activation of a peptide C-terminal amide protecting group to the corresponding methyl ester. We found that this conversion is efficiently catalysed by Stenotrophomonas maltophilia peptide amidase in neat organic media. The system excludes the possibility of internal peptide cleavage as the enzyme lacks intrinsic protease activity. The produced peptide methyl ester was used for peptide chain extension in a kinetically controlled reaction by a thermostable protease.
PYRIMIDINE DERIVATIVE
-
Page/Page column 129, (2010/11/24)
This invention provides pyrimidine derivatives represented by a formula, in the formula, ring A stands for carbocyclic group or heterocyclic group, X 1 stands for hydrogen, lower alkyl, amino, etc., X 2 stands for hydrogen or lower alkyl, Y stands for a direct bond or sulfur or nitrogen, n stands for an integer of 0 - 4, and Ar stands for a group of the following formula, or a salt thereof, which concurrently exhibit 5-HT 1A agonistic activity and 5-HT 3 antagonistic activity and are useful for therapy and treatments of diseases such as IBS. The invention furthermore provides a therapeutic method of IBS, characterized by having 5-HT 1A agonistic activity and 5-HT 3 antagonistic activity work simultaneously and cooperatively in vivo, which comprises either administering 5-HT 3 antagonistic agent which concurrently exhibits 5-HT 1A agonistic activity, or administering 5-HT 1A agonistic agent and 5-HT 3 antagonistic agent simultaneously, in sequence or at an interval.
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.
Le chloroformiate d'isopropenyle (IPCF) en chimie des peptides. I. Un bon reactif pour le couplage peptidique : synthese de dipeptides modeles
Jaouadi, M.,Selve, C.,Dormoy, J. R.,Castro, B.
, p. 409 - 412 (2007/10/02)
Isopropenyl chloroformate was used as an activating agent of N-protected amino-acids in the mixed anhydride method.This new reagent allows to run mixed anhydrides couplings at room temperature.
SYNTHESIS OF 3(NH2); Pro3; D-Ala6>- and 2(NO2); Pro3; D-Ala6>LULIBERINS
Burov, S. V.,Kaurov, O. A.,Martynov, V. F.,Smirnova, M. P.
, p. 518 - 524 (2007/10/02)
In order to study the influence of substituents of the aromatic ring of D-phenylalanine on the inhibiting capacity of luliberian analogs, we have synthesized two new analogs: 2; Pro3; D-Ala6>- and
