A variety of aliphatic, aromatic and heterocyclic nitriles have been
readily hydrolysed into the corresponding amides and/or acids under very
mild conditions using Rhodococcus sp. AJ270. The
nitrile hydratase involved in this novel nitrile-hydrolysing
microorganism efficiently hydrates most nitriles tested, irrespective of
the electronic and steric effects of the substituents, to form the
amides. Conversion of amides into acids catalysed by the associated
amidase is rapid and efficient in most cases. Substrates bearing an
adjacent substituent (which may be an ortho
substituent on an aromatic nitrile, an adjacent heteroatom in a
heterocyclic ring or a geminal substituent in an
α,β-unsaturated nitrile) undergo slow hydrolysis of the
amides allowing efficient amide isolation. The scope, limitations and
reaction mechanism of this enzymatic process have been systematically
studied. A molecular size of >7 Å diameter and
the presence of functions capable of metal complexation near to the
nitrile inhibit hydrolysis.
多种脂肪族、芳香族和杂环
腈类化合物在非常温和的条件下使用 Rhodococcus sp. AJ270 微
生物可以被容易地
水解成相应的酰胺和/或酸。这种新型腈
水解微
生物中涉及的
腈水合酶高效地将大多数测试的腈化合物
水合形成酰胺,不论取代基的电子和立体效应如何。在大多数情况下,与酰胺酶相关的酸催化反应迅速且高效。具有相邻取代基的底物(可能是芳香腈的邻位取代基,杂环中相邻的杂原子或α,β-不饱和腈中的二重取代基)的酰胺缓慢
水解,从而允许高效分离酰胺。该酶促过程的应用范围、局限性和反应机制已被系统研究。分子直径大于7 Å 的大小以及在腈附近存在能够与
金属络合的功能会抑制
水解。