Used as a reduced form of nicotinamide cofactor in enzymatic reduction reactions, particularly in biocatalysis and organic synthesis. It serves as a mimic of NADH, transferring hydride ions to substrates in stereoselective transformations, such as the reduction of ketones, aldehydes, and imines. Preferred in some systems due to improved stability and solubility compared to natural cofactors. Enables greener chemical processes by supporting enzyme-coupled reactions with lower catalyst loading and higher selectivity.