beta-Nicotinamide adenine dinucleotide, disodium salt

One of the biologically active forms of nicotinic acid. Serves as a coenzyme of hydrogenases and dehydrogenases. NAD usually acts as a hydrogen acceptor, forming NADH which then serves as a hydrogen donor in the respiratory chain. Present in living cells primarily in the reduced form (NADPH) and is involved in synthetic reactions. Occurs in 2 forms, α-NAD and β-NAD, distinguished by the configuration of the ribosyl nicotinamide linkage. Only the β-anomer is bioactive.