Biocatalysis can be defined as utilization of natural catalysts, such as protein enzymes, to perform chemical transformations on organic compounds. Both enzymes that have been more or less isolated or enzymes still residing inside living cells are employed for this task ^{[1] [2] [3]}. A catalyst (Greek: καταλύτης) is a substance that accelerates the rate of a chemical reaction, at some temperature, but without itself being transformed or consumed by the reaction (see also catalysis). ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... An organic compound is any of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates and carbon oxides. ...

History

Biocatalysis underpins some of the oldest chemical transformations known to humans, for brewing predates recorded history. The oldest records of brewing are about 6000 years old and refer to the Sumerians. A 16th century brewer A 21st century brewer This article concerns the production of alcoholic beverages. ... Sumer (or Shumer, Sumeria, Shinar, native ki-en-gir) formed the southern part of Mesopotamia from the time of settlement by the Sumerians until the time of Babylonia. ...

The employment of enzymes and whole cells have been important for many industries for centuries. The most obvious usages have been in the food and drink businesses where the production of wine, beer, cheese etc. is dependent on the effects of the microorganisms. A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). ...

More than one hundred years ago, biocatalysis was employed to do chemical transformations on non-natural man-made organic compounds, and the last 30 years have seen a substantial increase in the application of biocatalysis to produce fine chemicals, especially for the pharmaceutical industry. Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. ... This is a list of pharmaceutical and biotech companies that are major manufacturers on global or national markets : Abbott Laboratories Able Laboratories Akzo Nobel Allergan Almirall Prodesfarma Alphapharm Altana (previously Byk Gulden) ALZA, part of Johnson & Johnson Amgen AstraZeneca, formed from the merger of Astra AB and Zeneca Group PLC...

Advantages of Biocatalysis

The key word for organic synthesis is selectivity which is necessary to obtain a high yield of a specific product. There are a large range of selective organic reactions available for most synthetic needs. However, there is still one area where organic chemists are struggling, and that is when chirality is involved, although considerable progress in chiral synthesis has been achieved in recent years. Organic synthesis is the construction of organic molecules via chemical processes. ... Chemical reactions are defined usually in small contexts (only up to a small number of neighbouring atoms), such generalizations are a matter of utility. ... Organic reactions are chemical reactions involving organic compounds. ... Optical isomerism is a form of isomerism (specifically stereoisomerism) where the two different isomers are the same in every way except being non-superposable mirror images of each other. ... The two optical isomers of bromochlorofluoromethane Chiral synthesis (also called asymmetric synthesis) is organic synthesis which preserves or introduces a desired chirality. ...

Enzymes display three major types of selectivities:

• Chemoselectivity: Since the purpose of an enzyme is to act on a single type of functional group, other sensitive functionalities, which would normally react to a certain extent under chemical catalysis, survive. As a result, biocatalytic reactions tend to be "cleaner" and laborious purification of product(s) from impurities emerging through side-reactions can largely be omitted.
• Regioselectivity and Diastereoselectivity: Due to their complex three-dimensional structure, enzymes may distinguish between functional groups which are chemically situated in different regions of the substrate molecule.
• Enantioselectivity: Since almost all enzymes are made from L-amino acids, enzymes are chiral catalysts. As a consequence, any type of chirality present in the substrate molecule is "recognized" upon the formation of the enzyme-substrate complex. Thus a prochiral substrate may be transformed into an optically active product and both enantiomers of a racemic substrate may react at different rates.

These reasons, and especially the latter, are the major reasons why synthetic chemists have become interested in biocatalysis. This interest in turn is mainly due to the need to synthesise enantiopure compounds as chiral building blocks for drugs and agrochemicals. Chemical reactions are defined usually in small contexts (only up to a small number of neighbouring atoms), such generalizations are a matter of utility. ... In chemistry, regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions. ... Diastereomers are stereoisomers that are not enantiomers or mirror images of each other. ... In organic chemistry, functional groups (or moieties) are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... In chemistry, two stereoisomers are said to be enantiomers if they are mirror images of each other. ... This article is about the class of chemicals. ... In chemistry two stereoisomers are said to be enantiomers if one can be superimposed on the mirror image of the other. ... This article does not cite any references or sources. ... Agrichemical (or agrochemical) is a generic term for the various synthetic chemical products manufactured and sold for use in agriculture. ...

Another important advantage of biocatalysts are that they are environmentally acceptable, being completely degraded in the environment. Furthermore the enzymes act under mild conditions, which minimizes problems of undesired side-reactions such as decomposition, isomerization, racemization and rearrangement, which often plague traditional methodology. In chemistry, isomerization is the transformation of a molecule into a different isomer. ... In chemistry racemization refers to partial conversion of one enantiomer into another. ... A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. ...

Asymmetric biocatalysis

The use of biocatalysis to obtain enantiopure compounds can be divided into two different methods;

1. Kinetic resolution of a racemic mixture
2. Biocatalysed asymmetric synthesis

In kinetic resolution of a racemic mixture, the presence of a chiral object (the enzyme) converts one of the enantiomers into product at a greater reaction rate than the other enantiomer. In kinetic resolution two enantiomers show different reaction rates in a chemical reaction thereby creating an excess of the less reactive enantiomer [1]. This excess goes through a maximum and disappears on full completion of the reaction. ... Iron rusting - a chemical reaction with a slow reaction rate. ...

The racemic mixture has now been transformed into a mixture of two different compounds, making them separable by normal methodology. The maximum yield in such kinetic resolutions is 50%, since a yield of more than 50% means that some of wrong isomer also has reacted, giving a lower enantiomeric excess. Such reactions must therefore be terminated before equilibrium is reached. If it is possible to perform such resolutions under conditions where the two substrate- enantiomers are racemizing continuously, all substrate may in theory be converted into enantiopure product. This is called dynamic resolution. In chemistry two stereoisomers are said to be enantiomers if one can be superimposed on the mirror image of the other. ...

In biocatalysed asymmetric synthesis, a non-chiral unit becomes chiral in such a way that the different possible stereoismers are formed in different quantities. The chirality is introduced into the substrate by influence of enzyme, which is chiral. Yeast is a biocatalyst for the enantioselective reduction of ketones. Typical divisions Ascomycota (sac fungi) Saccharomycotina (true yeasts) Taphrinomycotina Schizosaccharomycetes (fission yeasts) Basidiomycota (club fungi) Urediniomycetes Sporidiales Yeasts are a growth form of eukaryotic microorganisms classified in the kingdom Fungi, with approximately 1,500 species described. ... Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ... Ketone group A ketone (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ...

The biocatalytic Baeyer-Villiger oxidation is another example of a biocatalytic reaction. In one study a specially designed mutant of Candida antarctica was found to be an effective catalyst for the Michael addition of acrolein with acetylacetone at 20°C in absence of additional solvent ^[4]. The Baeyer-Villiger oxidation is an organic reaction in which a ketone is oxidized to an ester by treatment with peroxy acids or hydrogen peroxide. ... Species C. albicans C. dubliniensis C. glabrata C. guilliermondii C. kefyr C. krusei C. lusitaniae C. milleri C. oleophila C. parapsilosis C. tropicalis C. utilis Candida is a genus of yeasts. ... // Definition The Michael reaction, as commonly defined, is the 1,4-addition of a stabilized carbon nucleophile to an alpha,beta-unsaturated carbonyl compound. ... In organic chemistry, acrolein or propenal is the simplest unsaturated aldehyde. ... R-phrases , S-phrases , , , Flash point 34 °C Autoignition temperature 340 °C Explosive limits 2. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ...

Another study demonstrates how racemic nicotine (mixture of S and R-enantiomers 1 in scheme 3) can be deracemized in a one-pot procedure involving a monoamine oxidase isolated from Aspergillus niger which is able to oxidize only the amine S-enantiomer to the imine 2 and involving an ammonia / borane reducing couple which can reduce the imine 2 back to the amine 1 ^[5]. In this way the S-enantiomer will continuously be consumed by the enzyme while the R-enantiomer accumulates. It is even possible to stereoinvert pure S to pure R. This article is about the chemical compound. ... In chemistry a one-pot synthesis is a strategy with the aim to improve the effiency of a chemical reaction whereby a reactant is subjected to successive chemical reactions in one and the same reactor. ... ... The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... The general structure of an imine An imine is a functional group or chemical compound containing a carbon-nitrogen double bond. ... For other uses, see Ammonia (disambiguation). ... In chemistry a borane is a chemical compound of boron and hydrogen. ... A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ...

References