5616-20-6Relevant 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.
New hydantoinases from thermophilic microorganisms - Synthesis of enantiomerically pure D-amino acids
Keil,Schneider,Rasor
, p. 1257 - 1260 (2007/10/02)
A series of 14 D-α-amino acids were prepared in high chemical and optical yields from the corresponding racemic hydantoins by employing two novel hydantoinases from thermophilic microorganisms.
Mechanism of Asymmetric Production of D-Amino Acids from the Corresponding Hydantoins by Pseudomonas sp.
Yokozeki, Kenzo,Kubota, Koji
, p. 721 - 728 (2007/10/02)
The mechanism of asymmetric production of D-amino acids from the corresponding hydantoins by Pseudomonas sp.AJ-11220 was examined by investigating the properties of the enzymes involved in the hydrolysis of DL-5-substituted hydantoins.The enzymatic production of D-amino acids from the corresponding hydantoins by Pseudomonas sp.AJ-11220 involved the following two successive reactions; the D-isomer specific hydrolysis, i.e., the ring opening of D-5-substituted hydantoins to D-form N-carbamyl amino acids by an enzyme, D-hydantoin hydrolase (D-HYD hydrolase), followed by the D-isomer specific hydrolysis, i.e., the cleavage of N-carbamyl-D-amino acids to D-amino acids by an enzyme, N-carbamyl-D-amino acid hydrolase (D-NCA hydrolase).L-5-Substituted hydantoins not hydrolyzed by D-HYD hydrolase were converted to D-form 5-substituted hydantoins through spontaneous racemization under the enzymatic reaction conditions.It was proposed that almost all of the DL-5-substituted hydantoins were stoichiometrically and directly converted to the corresponding D-amino acids through the successive reactions of D-HYD hydrolase and D-NCA hydrolase in parallel with the spontaneous racemization of L-5-substituted hydantoins to those of DL-form.
