Study on Asymmetric Synthesis of Chiral Precursor R(-)-mandelic Acid

OBJECTIVE To study the synthesis of chiral precursor R(-)-mandelic acid obtained by asymmetric bioreduction of phenylglyoxylic acid.METHODS Saccharomyces cerevisiae strains S.c.1,S.c.3 and S.c.10 were selected as original strains for further higher production of chiral precursor R(-)-mandelic acid.The mutant strain S.c.10.2.8 possessing effective transforming ability and almost absolute enantioselectivity was obtained using ultraviolet and microwave mutagenesis.RESULTS Under the conditions of initial substrate concentration 20 mmol·L-1,pH 6.6,temperature 34 ℃,the yield and the enantiomeric excesses of R(-)-mandelic acid were 85% and 99% respectively.CONCLUSION Biotransformaton is a potential alternative method to produce chiral precursor R(-)-mandelic acid.