Asymmetric synthesis of (R)-mandelonitrile catalysed by (R)-ixynitrilase from almond in organic solvent

作者：Liu SL^*; Zong MH; Yu SW; Zhang XY; Xing M

来源：Chinese Journal of Catalysis, 2003, 24(1): 7-10.

• benzaldehyde
• hydrogen cyanide
• (R)-oxynitrilase
• asymmetric synthesis
• (R)-mandelonitrile

The synthesis of chiral cyanohydrins has attracted growing industrial interest over the last several years. This paper reports the asymmetric synthesis of (R)-mandelonitrile from benzaldehyde and hydrogen cyanide catalysed by (R)-oxynitrilase from almond in organic solvent like isopropyl ether. The conversion of benzaldehyde and enantiomeric excess of (R)-mandelonitrile were determined by gas chromatography on a beta-cyclodextrin chiral column. The effects of the enzymes from different sources, optimum enzyme concentration, ratio of HCN to benzaldehyde, substrate concentration, pH of the enzyme microenvironment and reaction temperature on the synthesis of (R)-mandelonitrile were explored. It was found that (R)-oxynitrilase from bitter almond was better than the one from sweet almond. Under the optimum conditions, such as enzyme concentration of 150 g/L, HCN to benzaldehyde molar ratio of 2.5, substrate concentration of 300 mmol/L, enzyme microenvironmental pH of 5.4, and reaction temperature of 0 similar to 5 degreesC, both the benzaldehyde conversion and enantiomeric excess of the products were as high as 99%.

• 出版日期2003-1
• 单位深圳大学; 华南理工大学