Chemoenzymatic Synthesis and its Advantages

Catalysis is the process in which a chemical reaction is performed in the presence of an enzyme. By employing a catalyst or an enzyme, the rate of the reaction increases. Such a process is said to be enzyme catalysis. Catalysts are the biological components present in the body that have a specific role to play. All the biological and metabolic reactions of the body are usually slow but occur faster with the help of these catalysts. Catalysts or enzymes are proteins that are formed by the arrangement of amino acids in a specific manner to perform metabolic reactions at a faster rate like digestion of food, digesting fats, carbohydrates, etc. Proteins are very much required by the body.

Enzymes are naturally produced or synthesised in the cells of living organisms. Ribosomes, which are small structures in the cell, produce proteins by linking various amino acids according to the instructions given by RNA in the nucleus of a cell. Nowadays, enzymes are produced in the laboratory also. Such enzymes are non-natural enzymes that are obtained by using modern biotechnology techniques. These modified non-natural enzymes are utilised in performing some reactions which cannot be catalysed by natural enzymes or by classical methods of catalysis. The process in which either natural or non-natural enzymes are utilised to perform an organic chemical synthesis is called chemoenzymatic synthesis.

Briefing the content: The Chemoenzymatic synthesis reactions play a major role in the field of applied catalysis.

These reactions occur in multi step sequences, whereas the biocatalytic reactions (catalysed biological reactions) combine with other changes, which provides very efficient tools in preparative organic synthesis and materials chemistry. In the catalysed biological reactions, the enzymes that are held responsible for the metabolism of cells are used by organic chemists to perform highly selective and specific chemical transformations in mild conditions of pH and temperature, which are usually difficult to achieve by the classical methods.

Catalysed biological reactions are drawing greater attention to the eco-friendly synthetic processes used for either laboratory purposes or synthesis or industries. These techniques avoid a few drawbacks caused by synthetic methods, such as these being cost-effective or very economical, less toxic reagents, mild conditions for reaction, and fewer side reactions and minimum by-products.

Chemo enzymatic reactions have been studied for a few decades by many researchers in the synthesis of renewable resources(resources that can be used again and again) obtained from biomass and in the preparation of bio-based monomers to enhance the features of polymers and materials.

In chemoenzymatic synthesis reactions, the step that involves the addition of a catalyst to the substrate is an asymmetric reaction that forms a new chemical bond by breaking the existing chemical bonds in a sterically controlled manner. This is very important in obtaining or preparing an enantiopure form of the compound by the industry. A sterically controlled manner is to direct the reaction in a particular way to obtain the required product. Asymmetric or chiral carbon is carbon with no symmetry or carbon with four different groups around it. Such carbon is chiral carbon. The chirality of carbon in such reactions is very important for the efficiency and specificity of drugs.

Chirality of the carbon or group is a very important factor because their effect in the biological system depends strongly on the interaction between the receptors and enzymes in various parts of the body. Chemoenzymatic synthesis can be usually carried out either by using isolated and more stable enzymes that reduce by-products or by whole cells that have cofactor regeneration systems internally and act as green chemicals. Drugs obtained by organic synthesis are highly specific and have chiral carbon that acts specifically on the target. 

Advantages

The enzymes that are used in chemoenzymatic synthesis are completely harmless to the environment, and they are biodegradable. (which means they decompose easily when they are disposed of).

The enzymes in chemoenzymatic synthesis react or perform the activity under mild or basic biological conditions; due to this, unwanted reactions such as decomposition, isomerisation, etc., can be minimised. So, the disposal of unwanted products into the ground can be reduced.

The enzymes that are used in the chemoenzymatic synthesis are usually immobilised ( fixed in a position to not move) on the solid surface. These enzymes are observed to have high stability and be reused effectively. Such enzymes are used to react continuously in microreactors.