ENANTIOSEPARATION OF 5-MONOSUBSTITUTED HYDANTOINS BY CAPILLARY GAS-CHROMATOGRAPHY - INVESTIGATION OF CHEMICAL AND ENZYMATIC RACEMIZATION

The chemical as well as the enzymatic racemization of R- and S-5-monosubstituted hydantoin derivatives play an important role in the chemoenzymatic synthesis of optically pure D- or L-amino acids. To study these reactions, specifically with 5-alkylhydantoins enantiomer-separation by capillary gas chromatography, octakis(2,6-di-O-methyl-3-O-pentyl)-gamma-cyclodextrin as a chiral stationary phase was used. It will be shown that this method allows the sensitive and reproducible detection of a wide range of substrates in a short time. Examples are given for the chemical racemization of different 5-alkylhydantoins as well as for their enzymatic racemization by a hydantoin racemase of Arthrobacter sp. DSM 3745.