Biotransformation functional groups

While the enzymes involved in detoxication processes are nonspecific in the classical sense of intermediary metabolism, they often have distinct specificities both for organic functional groups and for the electronic, steric, and stereochemical environments where these functional groups are located. Enzyme specificity based on organic functional groups and their environments leads to a wide diversity in the alkaloid substrates possible and therefore the products obtained from biotransformation. This section of the chapter will concentrate principally on the enzymes themselves, including general concepts of substrate specificity and mechanism. 

METEOR S biotransformation rules are generic reaction descriptors, and the versatile structural representation used in the system allows each atom or bond to have specific physicochemical properties. This approach provides more details than simple hard-coded functional group descriptors (313), but this flexibility also can give rise to an avalanche of data. METEOR manages the amount of data by predicting which metabolites are to be formed rather than all the possible outcomes (310,312,314,315). At high certainty levels, when chosen, only the more likely biotransformations are requested. At lower likelihood levels, the more common metabolites are also selected for examination. Currently, METEOR knowledge-based biotransformations are exclusively for mammalian biotransformations (phase I and phase II) (314,315). 

The versatility of these reduction systems are demonstrated by the next few examples, chosen to show that a wide range of functional groups are tolerated by these biocatalysts and how the biotransformations can be applied to synthesize intermediates in API production. Zhu et from Biocatalytics have devel-... 

Many biotransformations are simple functional group conversions, with rates dependent on a range of properties of the molecule and the organism. The various possible biotransformations, including spontaneous reactions, can be viewed as competing reactions kinetically slow biotransformations are frequently only apparent in the absence of alternative rapid biotransformations. Noncovalent protein binding of chemicals may reduce the availability for enzymic metabolism and... 

Biotransformations are chemical reactions that are induced by enzymes in the cells. Sometimes it is possible to isolate the enzymes and to carry out the chemical reaction in a separate reactor in the absence of living cells. Starting materials are single chemical compounds or mixtures of related compounds, which are converted to the product with high selectivity. Specificity has several levels Conversion of one compound in a mixture of similar compounds or conversion of only one functional group on a complex molecule with many functional groups. 

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