- Enantioselective biocatalytic hydrolysis of beta-aminonitriles to beta-amino-amides using Rhodococcus rhodochrous ATCC BAA-870, by Varsha Chhiba, Moira L. Bode, Kgama Mathiba, Wendy Kwezi, Dean Brady in Journal of Molecular Catalysis B: Enzymatic [doi:10.1016/j.molcatb.2011.12.005]
“A range of β-aminonitriles (3-amino-3-phenylpropanenitrile and derivatives) were synthesised by reaction of various benzonitriles with acetonitrile and subsequent reduction of the resulting acrylonitrile products. These compounds were hydrolysed to the corresponding amides using the nitrile biocatalytic activity of Rhodococccus rhodocrous ATCC BAA-870. Results showed that the nitrile hydratase enzyme was enantioselective for these compounds, in particular 3-amino-3-p-tolylpropanenitrile and 3-amino-3-(4-methoxyphenyl)propanenitrile and the corresponding amides (up to 85% in one case).” They found interesting levels of steric hindrance (probably) when the amino group was functionalized, and they had most success when the biotransformations were run at pH9 to minimize as much as possible protonation of the amine if it wasn’t derivatized. Obviously it being a Rhodococccus, this is an example of enantioselectivity with an iron-centred NHase.
- Biotransformation of the Neonicotinoid Insecticide Thiacloprid by Bacterium Variovorax boronicumulans Strain J1 and Mediation of the Major Metabolic Pathway by Nitrile Hydratase by Hui-Juan Zhang , Qian-Wen Zhou , Guang-Can Zhou , Yu-Min Cao , Yi-Jun Dai , Wei-Wei Ji , Guang-Dong Shang , and Sheng Yuan in Journal of Agricultural and Food Chemistry [DOI: 10.1021/jf203232u]
“A neonicotinoid insecticide thiacloprid-degrading bacterium strain J1 was isolated from soil and identified as Variovorax boronicumulans by 16S rRNA gene sequence analysis… A 2.6-kb gene cluster from V. boronicumulans J1 that includes the full length of the nitrile hydratase gene was cloned and investigated by degenerate primer polymerase chain reaction (PCR) and inverse PCR. The nitrile hydratase gene has a length of 1304 bp and codes a cobalt-type nitrile hydratase with an alpha-subunit of 213 amino acids and a beta-subunit of 221 amino acids.” This protein was then expressed in an active form in E. coli BL21. This bacterium is a boron-accumulating microbe isolated from soil.
