Stereoselective hydrolysis of aryl-substituted dihydropyrimidines by hydantoinases

Abstract

In this study, we investigated the possibility of using a modified hydantoinase process for the production of optically pure β-amino acids. Two aryl-substituted dihydropyrimidines D,L-6-phenyl-5,6-dihydrouracil (PheDU) and para-chloro-D,L-6-phenyl-5,6-dihydrouracil (pClPheDU) were synthesized. Hydrolysis of these novel substrates to the corresponding N-carbamoyl-β-amino acids by three recombinant D-hydantoinases and several bacterial strains was tested. All applied recombinant D-hydantoinases and eight bacterial isolates catalyzed the conversion of PheDU to N-carbamoyl-β-phenylalanine (NCβPhe). Some of these biocatalysts showed an enantioselectivity for either the D- or the L-PheDU enantiomer. The second dihydropyrimidinase substrate pClPheDU was hydrolyzed by all three recombinant D-hydantoinases and six of the wild-type strains. To our knowledge, this is the first dihydropyrimidinase activity reported with this aryl-substituted dihydropyrimidine. For selected biocatalysts, hydantoinase activity towards aryl-substituted hydantoins was demonstrated as well. However, none of the bacterial strains tested so far exhibited any carbamoylase activity towards NCβPhe.

Novel amidases of two Aminobacter sp. strains: Biotransformation experiments and elucidation of gene sequences

“…DSM24755 in LBi for all experiments (Engel et al 2011). The dihydropyrimidinase, hydantoinase and carbamoylase activities of Aminobacter sp.…”

“…The purity was proven by HPLC and 1  H-NMR. PheDU used for biotransformation experiments and para -chloro-D,L- N -carbamoyl-β-phenylalanine ( p ClNCβPhe) were prepared as described elsewhere (Engel et al 2011). …”

“…DSM24754 and Aminobacter sp. DSM24755 were kindly provided by Dr. A. Puñal and first described by Engel et al 2011.…”

“…Several bacterial isolates, among them Aminobacter sp. DSM24755, showed an enantioselective conversion of phenyldihydrouracil (Engel et al 2011). …”

Transaminases and their Applications

“…Starting from N-acetylated ethyl esters, lipases [92], aminomutases [96,97], acylases [98], monooxygenases [99], and ami dases [100] were used for the synthesis of β-amino acids.…”