Metabolism (biotransformation) can be defined as enzymatic conversion of natural and chemically synthesized product, into substance having specifically modified structure.
Drug metabolism is generally considered as a detoxification process leading to the formation of more polar substances, which are easily excreted from the organism.
Interestingly, in some cases, the metabolism of a drug can lead to the formation of pharmacological or toxicological active compound. Hence, the understanding of drug metabolism plays an important role in the development of new drug entities.
1. STEREOSELECTIVE SYNTHESIS IN CYCLIC b-KETOESTERS [19-21]
Synthesis of chiral alcohols (active form) from cyclic b-ketoesters which are important precursors for a large number of pharmaceuticals (lactones and epoxides) is met through the microbial transformation, despite tremendous scientific and technical advances. By using microorganisms either their yield can be increased or in some cases one can obtain only a single stereoisomeric derivative which is impossible by synthetic means.