32865-17-1Relevant academic research and scientific papers
Synthesis of Each Stereoisomer of Phenylalanine and Evaluation of the Stereochemical Course of the Reaction of (R)-Phenylalanine with (S)-Phenylalanine Ammonia-lyase
Easton, Christopher J.,Hutton, Craig, A.
, p. 3545 - 3548 (1994)
The four stereoisomers of phenylalanine have been prepared, each as a single enantiomer in ca. 98percent diastereoisomeric excess and with ca. 99percent deuterium incorporation, by side-chain bromination of phenylalanine derivatives, followed by deuteriolysis of each of the diastereoisomeric product bromides with deuterium over 5percent palladium-on-carbon.The latter reactions proceeded with retention of configuration. (2R,3S)-Phenylalanine reacted with (S)-phenylalanine ammonia-lyase to give -trans-cinnamic acid, with 92percent deuterium incorporation, while the (2R,3R)-stereoisomer of the deuterated phenylalanine gave -trans-cinnamic acid with 27percent deuterium incorporation.These results indicate that reaction of (R)-phenylalanine with the enzyme involves mainly loss of the 3-pro-R hydrogen and ammonia, in an antiperiplanar elimination process analogous to that previously reported for (S)-phenylalanine, while a minor pathway for reaction of (R)-phenylalanine is either isomerization to (S)-phenylalanine, before elimination, or synperiplanar elimination.
Kinetic and solvent isotope effects on biotransformation of aromatic amino acids and their derivatives
Kańska, Marianna,Jemielity, Jacek,Paj?k, Ma?gorzata,Pa?ka, Katarzyna,Podsadni, Katarzyna,Winnicka, El?bieta
, p. 627 - 634 (2016/12/26)
Aromatic amino acids such as l-phenylalanine, l-tryptophan, 3′,4′-dihydroxy-l-phenylalanine (l-DOPA), and their derivatives 3′,4′-dihydroxyphenylacelaldehyde (DOPAL) and 3′,4′-dihydroxyphenylethanol (DOPET), play an essential role in human metabolic processes. Incorrect or slow biotransformation of these compounds leads to some metabolic dysfunctions and in some cases to some neurodegenerative diseases. Therefore, studies of the biotransformation mechanisms of these metabolites draw biochemists' and medical researchers' attention. This study investigates the mechanisms of biotransformation of the aforementioned compounds using kinetic (KIE) and solvent (SIE) isotope effect methods. The overview presents the results and the numerical values of KIE and SIE methods, obtained in the study of biotransformation of l-phenylalanine, 5′-chloro-l-tryptophan, and l-DOPA, catalyzed by the enzymes from the lyases group (phenylalanine ammonia lyase, tryptophan indole-lyase, and tyrosine decarboxylase). Deuterium KIE was also determined during the deamination of 2′-chloro-l-phenylalanine in the presence of the enzyme l-phenylalanine dehydrogenase, as well as in the conversion of DOPAL into DOPET catalyzed by the enzyme alcohol dehydrogenase. The values of KIE and SIE have been determined using a noncompetitive spectrophotometric and a competitive (combined with internal radioactivity standard) radiometric methods.
Isotope effects in oxidative deamination of L-phenylalanine
Kanska, Marianna,Skowera, Katarzyna
body text, p. 443 - 444 (2011/05/06)
The mechanism of reversible oxidative deamination of L-phenylalanine into phenylpyruvic acid catalyzed by enzyme L-Phenylalanine Dehydrogenase (EC 1.4.1.20) using kinetic and solvent isotope effects was studied. Copyright
