Figure displays sixteen well-characterized cofactor mimics found in the literature, three of which contain variations in the R3 substituent such that they are not nicotinamide structures, however, they are still classified as NCBs for their ability to replace NAD(P)H. Many enereductases and some oxidoreductase enzymes have been shown to readily accept NCBs as redox cofactors. Other types of enzymes do not always naturally accept NCBs, either due to poor binding or incompatible reduction potentials, but activity can be engineered for these synthetic cofactors. Figure . A) Reduction of NAD + . B) Selected NCBs previously seen in literature. The 1,4dihydropyridine in both NAD(P)H and NCBs, shown in teal, is featured as the one constant design component throughout this work.