Biocatalysis

Biocatalysis

Biocatalysis uses isolated enzymes and whole cells for chemical transformation. Biocatalysis enables cleaner and more efficient process and creates new environmentally friendly processes. Biocatalysis has many advantages over traditional chemical processes- improved productivity, milder reaction condition, better selectivity and simplified workup. This leads to safer chemistry/processes and better cost efficiency.

Enzymes can improve productivity by increasing the yield and shortening the synthetic route. The reaction conditions are also milder since the reactions are mainly done in water at ambient temperature. Enzymes can replace costly chiral resolving agents, while the enantiomer and regioselectivity obtained are usually much higher than traditional chemistry. It also simplifies the work up with fewer by-products, lower impurity level and fewer wastes.




The biocatalysis tool box contains different classes of enzymes which are used for different chemical transformations. The widely used enzymatic tool box is given below:

Class

Reaction

Example

Oxidoreductases

Oxidation/reduction

Alcohol dehydrogenase

Monooxygensaes

Transferases

Transfer of functional group

Transaminases

Hydrolases

Hydrolysis reaction

Ester, amide hydrolysis

Lipases

Proteases

Epoxide hydrolases

lyases

Bond cleavage other than hydrolysis, elimination, double bond formation

Decarboxylases, Dehydratases




Reactions:

1. Kinetic resolution of Carboxylic acid, esters, amides, amino ester, epoxides, diols, alcohols, nitriles and amines. This can be done by one class of enzyme called “hydrolases” comprised of lipase, esterases, amidases and epoxide hydrolases etc. Those are the most commercially valuable enzymes and are widely used in the detergent, food and pharmaceutical industry.


2

2. Asymmetric reduction of ketones

This transformation is done by the oxidoreductase class of enzymes including alcohol dehydrogenases and Ketoreductases. Co-factors in the form of NADH or NADPH are required, and they can be recycled in the reactions.


6

The chiral reduction of ketone involves the use of Chiral auxiliary and toxic borane reagent (CBS reduction). The use of precious metal catalyst like Ru has made these processes greener. But so far the ketone reduction using the enzyme technology is the cleanest technology. This reaction is done in water and virtually no by-product is obtained, making this process safe and environmentally friendly.


3. Synthesis of chiral amine

Chiral amines serve as important building blocks in organic synthesis particularly in the synthesis of APIs. Enzymes offer unprecedented enatioselectivity >99% in the synthesis of chiral amines. Transaminases catalyse the formation of chiral amines from ketones. Amino acid dehydrogenases are a class of enzyme that can transform keto-acids to chiral amino acids. Imine reductases and amine oxidases are also used to synthesize chiral amines.


Transaminase.

4


Imine reductase

5

Equipment

Plate Shaker

Centrifuge

Automatic Pipette

Table Top Mixers

Equipment

WeChat