New hydantoinases from thermophilic microorganisms — Synthesis of enantiomerically pure D-amino acids
摘要:
A series of 14 D-alpha-amino acids were prepared in high chemical and optical yields from the corresponding racemic hydantoins by employing two novel hydantoinases from om thermophilic microorganisms.
The present invention relates to compounds and pharmaceutical preparations and their use in therapy for preventing or treating trauma, ischemia, stroke and degenerative diseases associated with cell death. Methods and compositions of the invention are particularly useful for treating neurological disorders associated with cellular necrosis.
Methods for producing single diastereomers of isoleucine in high stereochemical purity are provided. D-isoleucine is produced by converting (R)-2-methylbutyraldehyde to a diastereomeric mixture of D-isoleucine hydantoin and L-allo-isoleucine hydantoin (5S-[(R)-1-methylpropyl]hydantoin) under conditions whereby no significant racemization of the chiral center in (R)-2-methylbutyraldehyde occurs, followed by contacting said diastereomeric hydantoin mixture with a D-hydantoinase to stereoselectively hydrolyze any D-isoleucine hydantoin in the mixture to the corresponding N-carbamoyl-D-isoleucine, preferably under conditions permitting the simultaneous epimerization of the chiral center at C-5 of the hydantoin. The simultaneous epimerization permits the reaction to be carried out to substantial completion so that the diastereomeric hydantoin mixture is converted to N-carbamoyl-D-isoleucine in high yield. The N-carbamoyl-D-isoleucine is then decarbamoylated to produce D-isoleucine. Similar procedures are used to produce single diastereomers of L-isoleucine, L-allo-isoleucine, and D-allo-isoleucine.
The present invention relates to compounds and pharmaceutical preparations and their use in therapy for preventing or treating trauma, ischemia, stroke and degenerative diseases associated with cell death. Methods and compositions of the invention are particularly useful for treating neurological disorders associated with cellular necrosis.
Es wird ein Verfahren beansprucht, mit dem aus tert-Butylhydantoin mittels einer (R)-spezifischen Hydantoinase N-Carbamoyl-(R)-tert.-Leucin gewonnen werden kann, das durch Reaktion mit Nitrit oder einer (R)-Carbamoylase zu (R)-tert-Leucin umgewandelt werden kann.