Nicotinamide coenzyme regeneration. Flavin mononucleotide (riboflavin phosphate) as an efficient, economical, and enzyme-compatible recycling agent

Abstract

The high cost of nicotinamide coenzymes currently acts as a deterrent to the widespread adoption of alcohol dehydrogenases as chiral catalysts for effecting stereospecific and selective CH(OH) .dblarw. C.dbd.O oxidoreductions on a preparative scale. Attempts to overcome this problem generally involve using catalytic amounts of coenzyme together with an auxiliary system capable of continuously regenerating its active form in situ. FMN was an effective, convenient and inexpensive reagent for in situ recycling of NAD+. Using horse liver alcohol dehydrogenase-catalyzed oxidation of cyclohexanol as a representative process, up to 50-fold NAD+-regeneration levels were achieved. This method is the most satisfactory and practical oxidative-mode recycling procedure yet developed for routine laboratory applications.