Nicotinamide adenine dinucleotide hydride reduced form cofactor

Oxidative reactions in catabolic sequences involve the removal of electrons from an intermediate. This process is controlled by dehydrogenases and often involves the participation of the cofactor nicotinamide adenine dinucleotide (NAD or NAD+). Electrons from the donor are transferred to NAD in the form of the hydride ion [ H-] to produce reduced NAD (NADH). In many reactions two hydrogen atoms are removed from the substrate, one in the form of the hydride ion, the other liberated as a proton accordingly, the reduction of NAD+ is often written as... 

Another topic related to water and organometallics has been developed by Fish, who is the author of Chapter 10. In particular. Fish has tried to overcome the problem of cofactor regeneration in biocatalysis. At least one-third of all known enzymes require the use of cofactors such as NAD (nicotinamide adenine dinucleotide) and its reduced form, 1,4-NADH, to perform oxidations or reductions. However, these cofactors are expensive and fairly complicated molecules. It has been shown that, in aqueous solution, some organometallic biomimetic models behave chemically like NAD and are able to abstract a hydride ion [249]. A key example is shown below where the hydride 33 reduces 31 into 34 (Scheme 1.27). 

Bacteria use two redox carriers nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH). The abbreviations in the parentheses denote the carriers when they are in the reduced form. When these molecules are in their oxidized forms (NAD+, NADP ), they abstract electrons from molecules in the form of a hydride and in the process, become reduced (NADH, NADPH). For example, the reaction A + NAD+ —> B + NADH occurs where B is more oxidized than A, and the electrons are transferred by adding a hydride to NAD to yield the reduced cofactor, NADH. 

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