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All total 4 Articles be found
All total 4 Articles be foundEnzymatic synthesis of chiral phenylalanine derivatives by a dynamic kinetic resolution of corresponding amide and nitrile substrates with a multi-enzyme system
Yasukawa, Kazuyuki,Asano, Yasuhisa
supporting information, p. 3327 - 3332 (2013/01/15)
Mutant α-amino-ε-caprolactam (ACL) racemase (L19V/L78T) from Achromobacter obae with improved substrate specificity toward phenylalaninamide was obtained by directed evolution. The mutant ACL racemase and thermostable mutant D-amino acid amidase (DaaA) from Ochrobactrum anthropi SV3 co-expressed in Escherichia coli (pACLmut/pDBFB40) were utilized for synthesis of (R)-phenylalanine and non-natural (R)-phenylalanine derivatives (4-OH, 4-F, 3-F, and 2-F-Phe) by dynamic kinetic resolution (DKR). Recombinant E. coli with DaaA and mutant ACL racemase genes catalyzed the synthesis of (R)-phenylalanine with 84% yield and 99% ee from (RS)-phenylalaninamide (400 mM) in 22 h. (R)-Tyrosine and 4-fluoro-(R)-phenylalanine were also efficiently synthesized from the corresponding amide compounds. We also co-expresed two genes encoding mutant ACL racemase and L-amino acid amidase from Brevundimonas diminuta in E. coli and performed the efficient production of various (S)-phenylalanine derivatives. Moreover, 2-aminophenylpropionitrile was converted to (R)-phenylalanine by DKR using a combination of the non-stereoselective nitrile hydratase from recombinamt E. coli and mutant ACL racemase and DaaA from E. coli encoding mutant ACL racemase and DaaA genes. Copyright
Synthesis of α-amino dithioesters and endothiodipeptides
Hartke, Klaus,Barrmeyer, Stephan
, p. 251 - 256 (2007/10/03)
The α-amino ester hydrochlorides (1) are converted into N-protected α-amino amides (3), α-amino thioamides (4) and α-amino dithiomethylesters (5). Condensation of 5 with the alkali salts of α-amino acids gives rise to the endothiodipeptide alkali salts (7). Johann Ambrosius Barth 1996.
