90899-85-7Relevant articles and documents
Rapid and efficient microwave-assisted synthesis of N-carbamoyl-L-amino acids
Verardo, Giancarlo,Geatti, Paola,Strazzolini, Paolo
, p. 1833 - 1844 (2008/02/02)
A rapid and efficient method for the synthesis of N-carbamoyl-L-amino acids is reported. The procedure, involving the reaction between urea and α-amino acids sodium salts, was performed under microwave conditions using an unmodified domestic microwave oven. A careful study of the operative conditions indicated proline (1d) as the less reactive substrate and phenylglycine (1e) as the more reactive one among all the α-amino acids tested. Substitution of urea with potassium cyanate produced a low conversion into the corresponding N-carbamoyl derivative, and a possible explanation of this result is reported. Copyright Taylor & Francis Group, LLC.
Mechanism of Asymmetric Production of L-Aromatic Amino Acids from the Corresponding Hydantoins by Flavobacterium sp.
Yokozeki, Kenzo,Hirose, Yoshiteru,Kubota, Koji
, p. 737 - 746 (2007/10/02)
The mechanism of asymmetric production of L-aromatic amino acids from the corresponding hydantoins by Flavobacterium sp.AJ-3912 was examined by investigating the properties of the enzymes involved in the hydrolysis of 5-substituted hydantoins corresponding to aromatic amino acids (AAH).The enzymatic hydrolysis of AAH by Flavobacterium sp.AJ-3912 consisted of the following two successive reactions; a hydrolytic ring opening reaction of DL-AAH to L- and D-form N-carbamyl aromatic amino acids (NCA), involving an enzyme (hydantoin hydrolase) followed by a hydrolytic cleaving reaction of the L-form NCA to L-aromatic amino acids involving another enzyme (N-carbamyl-L-aromatic amino acid hydrolase, abbreviated as L-NCA hydrolase).The ring opening reaction involving hydantoin hydrolase was not stereospecific, but the NCA cleaving reaction involving L-NCA hydrolase was completely L-specific.The pathway for the conversion of the by-produced D-form NCA to L-aromatic amino acids was as follows; conversion of D-form NCA to D-AAH through the reverse reaction of hydantoin hydrolase, and then conversion of the D-AAH to L-AAH through spontaneous racemization, followed by the successive hydrolysis of the L-AAH to L-aromatic amino acids by hydantoin hydrolase and L-NCA hydrolase.