Highly regioselective and efficient production of 1-cyanocyclohexaneacetamide byRhodococcus aetherivoransZJB1208 nitrile hydratase

Abstract

BACKGROUND The regioselective hydration of alicyclic α,ω‐dinitrile 1‐cyanocyclohexaneacetonitrile (1‐CCHAN), followed by hydrogenation of ω‐cyano group is a green and elegant route to gabapentin. As the selective chemical hydration of dinitrile is virtually impossible, a bioprocess for regioselective hydration of 1‐CCHAN was developed using microbial nitrile hydratase. RESULTS A newly isolated NHase producing strain, Rhodococcus aetherivorans ZJB1208, was successfully used for hydration of 1‐CCHAN. Some key parameters of the biocatalytic process, including reaction temperature, pH, catalyst loading and substrate loading, were optimized. The fed‐batch biotransformation was performed in non‐buffered water system with the continuous precipitation of 1‐cyanocyclohexaneacetamide. The substrate loading was increased up to 864 g L−1 (6.0 mol L−1), giving a product concentration of 966.7 g L−1 and biocatalyst yield (gproduct/gcat) of 204.2. CONCLUSION This study is the first example of microbial nitrile hydratase with both excellent regioselectivity and strong substrate tolerance for alicyclic dinitrile and affords a potentially industrial route to gabapentin. © 2015 Society of Chemical Industry

Recent Advances and Promises in Nitrile Hydratase: From Mechanism to Industrial Applications

“…In addition, an NHase isolated from Rhodococcus aetherivorans ZJB1208, was reported to possess the ability to regioselectively biotransform 1-cyanocyclohexaneacetonitrile into 1-cyanocyclohexaneacetamide with a biocatalyst yield (g product /g cat ) of 204.2. This result turns out to be a typical example of NHase showing both excellent regioselectivity and strong substrate tolerance for nitrile substrates and casts light on the potential industrial production of gabapentin (Zheng et al, 2016).…”

Enzymatic production of key intermediate of gabapentin by recombinant amidase from Pantoea sp. with high ratio of substrate to biocatalyst

“…Compounds 1-CCHAN and 1-CCHAA were provided by Zhejiang Chiral Medicine Chemicals Co., Ltd. (Hangzhou, China). Compound 1-CCHAM was prepared using 1-CCHAN as substrate by R. aetherivorans preserved in our laboratory [15]. Isopropyl-β-D-thiogalactopyranoside (IPTG) and kanamycin were purchased from Sigma.…”

“…However, some practical problems such as low substrate concentration and high biocatalyst loading restricted its industrial applications. Recently, a bioprocess for regioselective hydration of 1-CCHAN was developed using Rhodococcus aetherivorans ZJB1208 nitrile hydratase in our laboratory, and the concentration of product (1-cyanocyclohexaneacetamide, 1-CCHAM) accumulated as high as 966.7 g. L -1 [15]. Since the selective chemical hydrolysis of cyano and amide bond of 1-CCHAM is virtually impossible, amidase-catalyzed hydrolysis is the only facile way of preparing 1-CCHAA from 1-CCHAM ( Fig.…”

Regioselective Biocatalytic Transformations Employing Transaminases and Tyrosine Phenol Lyases

“…Among other selective transformations, lipases also catalyze the monoamidation of glutamic acid diesters [11], the monodeacetylation of di-or triacetoxyacetophenones by transesterification [12], and the monoacetylation of dihydroxybenzene derivatives with vinyl acetate [13]. Likewise, dinitriles have been hydrolyzed to the corresponding monocarboxylic acids by nitrilases [14] or to monoamides by nitrile hydratases [15] with moderate to excellent regioselectivity. Epoxide hydrolases showing opposite regioselectivity on the (S)-and (R)-enantiomer of the same substrate have been used for the enantioconvergent hydrolysis of racemic mixtures of oxiranes [16][17][18][19][20][21][22][23][24][25][26][27][28] into vicinal diols.…”