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 screening higher production of chiral precursor R(-)-mandelic acid.The mutant strain S.c.10.2.8 possessing effective transformaing ability and almost absolute enantioselectivity was obtained with the methods of ultraviolet and microwave mutagenesis.[Results] Under the conditions of initial substrate concentration 20mmol/L,pH6.6,temperature 34℃.The yield and the enantiomeric excesses of R(-)-mandelic acid were 85% and 99% respectively.[Conclusion] Biotransformation is a potential alternative method producing chiral precursor.R(-)-mandelic acid.