Advances in regeneration system of natural nicotinamide cofactor and its artificial analogues

Oxidoreductases have drawn considerable attention as mild and efficient catalysts in the fields of organic synthesis and medical sciences due to they can catalyze regio-, chemo-and stereoselective transformations that cannot be easily achieved by chemical catalysts. Cofactors are required in oxidoreductase-catalyzed reactions, commonly in the form of nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate, abbreviated as NAD(H) and NADP(H). Given the high cost and physical instability of NAD(H)/NADP(H), the stoichiometric usage is not practical for industrial applications. After decades, four main strategies such as enzymatic, chemical, electrochemical and photochemical method have been used for the cofactor regeneration. Meanwhile, the development of stable, highly active and inexpensive artificial nicotinamide cofactors particularly 1,4-dihydropyridine derivatives has led to a new breakthrough.