Epoxide Hydrolase Split The Study Of Benzyl Glycidyl Ether

Enantiopure epoxides are versatile chiral building-blocks in organic synthesis and can be used for convenient synthesis of many bioactive compounds. Therefore, enantiopure epoxides, such as benzyl glycidyl ether (BGE), are very important for pharmaceutical industry.An enzymatic method using epoxide hydrolase (EH) from Aspergillus niger G5 for resolution of BGE was investigated in the paper, with emphasis on strains isolation, cultivation, and bioconversion of racemic BGE.With BGE as a sole carbon source, 8 strains with epoxide hydrolase activity were isolated from soil samples. Among of them, strain GS showed the highest enantioselectivity and could convert stereoselectively racemic BGE to (R)-BGE.The enantioselectivity of Aspergillus niger G5 was strongly influenced by the medium composition. When the fermentation medium was composed of 1.0 % , 2.0% corn steep liquor and 1.0% NaCl, and initial pH was 4.0, the strain produced epoxide hydrolase with the highest enantioselectivity.The cells suspended in 50 mmol/L Tris-HCl buffer (pH 6.5) containing 2% (w/v) Tween 60 produced (R)-BGE of 100% ee and 43.3% of conversion rate in 3h from 20 mmol/L BGE.Using 200 mg/L freeze-dried crude epoxide hydrolase preparation from Aspergillus niger G5, 200 mmol/L of racemic BGE was resolved in 7 h with remaining (R)-BGE of 100% ee and 45.3% of conversion rate. That suggested that epoxide hydrolase of Aspergillus niger G5 could be used in the resolution of high concentration of BGE.