154844-41-4Relevant academic research and scientific papers
Phenylalanine ammonia-lyase: The use of its broad substrate specificity for mechanistic investigations and biocatalysis - Synthesis of L-arylalanines
Gloge, Andreas,Zon, Jerzy,Koevari, Agnes,Poppe, Laszlo,Retey, Janos
, p. 3386 - 3390 (2007/10/03)
Several fluoro-and chlorophenylalanines were found to be good substrates of phenylalanine ammonialyase (PAL/EC 4.3.1.5) from parsley. The enantiomerically pure L-amino acids were obtained in good yields by reaction of the corresponding cinnamic acids with 5M ammonia solution (buffered to pH 10) in the presence of PAL. The kinetic constants for nine different fluoro-and chlorophenylalanines do not provide a rigorous proof for but are consistent with the previously proposed mechanism comprising an electrophilic attack of the methylidene-imidazolone cofactor of PAL at the aromatic nucleus as a first chemical step. In the resulting Friedel-Crafts-type σ complex the β-protons are activated for abstraction and consequently the pro-S is abstracted by an enzymic base. Results from semi-empirical calculations combined with a proposed partial active site model showed a correlation between the experimental kinetic constants and the change in polarization of the pro-S Cβ-H bond and heat of formation of the σ complexes, thus making the electrophilic attack at the neutral aromatic ring plausible. Furthermore, while 5-pyrimidinylalanine was found to be a moderately good substrate of PAL, 2-pyrimidinylalanine was an inhibitor.
Synthesis of Heterocyclic β-Amino Acids. A Convenient Preparation of β-Amino-5-Pyrimidinepropanoic Acid and Derivatives.
Bovy, Philippe R.,Rico, Joseph G.
, p. 8015 - 8018 (2007/10/02)
The novel (2E)-1,1-dimethylethyl-3-(5-pyrimidinyl)-2-propenoate 3, obtained by Heck coupling between 5-bromopyrimidine and tert-butyl acrylate undergoes nearly quantitative Michael addition in t-butanol saturated with ammonia to the hitherto unknown β-amino-5-pyrimidinepropanoic ester 4.The synthetic utility of this reactions sequence is demonstrated by preparation of 4 on a multigram scale.The transformation of the ester to the free amino acid 5 and to the Cbz-N-protected amino acid 7 is described.The tert-butyl ester 4 and N-protected β-amino acid 7 are useful in peptide and peptidomimic synthesis.
