生物催化3-(4-氯苯基)-戊二腈去对称性水解合成光学纯巴氯芬的关键前体

Biocatalytic desymmetric hydrolysis of 3-(4-chlorophenyl)-glutaronitrile to the key precursor of optically pure baclofen

摘要:

研究了利用生物催化剂制备 (S)-4-氰基-3-(4-氯苯基)-丁酸。以3-(4-氯苯基)-戊二腈为底物，采用苯酚-次氯酸钠法对实验室保藏的菌株进行筛选，得到一株产物立体选择性较高的菌株赤霉菌Gibberella intermedia WX12，并对其催化特性和发酵条件进行了初步研究。以30 g/L的乳糖和20 g/L的蛋白胨分别为碳、氮源，发酵培养96 h，收集的菌体在50 mmol/L磷酸缓冲液 (pH 8.0) 中30 ℃催化反应24 h，将3-(4-氯苯基)-戊二腈转化为4-氰基-3-(4-氯苯基)-丁酸，产率为90％。将产物化学转化为巴氯芬，手性HPLC分析表明水解产物构型是 (S)，其对映异构体过量值ee＞99％。该产物可以用来合成光学纯的 (R)-和(S)-巴氯芬。

Abstract:

We produced (S)-4-cyano-3-(4-chlorophenyl)-butyrate by highly stereoselective biocatalyst in this study. A nitrilase-producing strain, named Gibberella intermedia WX12, was isolated by 3-(4-chlorophenyl)-glutaronitrile as substrate in the screening with phenol-sodium hypochlorite method. The fermentation conditions and catalytic properties of this strain were investigated. The preferred carbon and nitrogen sources for nitrilase production were lactose (30 g/L) and peptone (20 g/L). After being cultivated for 96 h, the cells were collected for use in biotransformation. The hydrolysis of 3-(4-chlorophenyl)-glutaronitrile was performed at 30 °C in phosphate buffer (pH 8.0, 50 mmol/L) for 24 h to give (S)-4-cyano-3-(4-chlorophenyl)-butyric acid with 90% yield and >99% of ee, which can be used for the synthesis of (R)- and (S)-baclofen. The configuration of product was determined by chemically converting it to baclofen and comparison with the authentic sample by chiral HPLC analysis.