Synthetic biology for organic syntheses

Since many useful organic compounds, such as pharmaceuticals and food additives, have asymmetric carbon atoms, there are enantiomers of them. In most cases, only one enantiomer is useful as a biologically active substance, the others not showing such activity and sometimes having a harmful effect. Therefore, a racemic mixture of such compounds which have been chemically synthesized cannot be used, especially for pharmaceuticals, and thus the troublesome optical resolution of the racemic mixture by means of a conventional organic synthetic process for such optically active substances is unavoidable. 

The use of heteropolyacids as catalysts for fine organic synthetic processes is developing. Syntheses of antioxidants, medicinal preparations, vitamins, biologically active substances, etc., have been reported and some are already applied in practice (10, 160). 

Vitamins serve the same roles in nearly all forms of life, but higher animals lost the capacity to synthesize them in the course of evolution. For instance, whereas E. coli can thrive on glucose and organic saJts, human beings require at least 12 vitamins in their diet. The bio.synthetic pathways for vitamins can be complex thus, it is biologically more efficient... 

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