engleski

Enzymatic cascade reaction for the synthesis of an imino aldol adduct: oxido-reduction coupled with aldol addition

Aldol adducts containing amino groups are important building blocks of many naturally occurring molecules such as iminosugars. In this work the oxidation of the amino alcohol catalyzed by alcohol dehydrogenase was coupled with aldol addition catalyzed by an aldolase, to synthesize an imino aldol adduct. Similar reaction system was found to be effective in our previous work. Several enzymes were tested as catalysts for oxidation of Cbz-N-3-amino-1, 2-propanediol to Cbz-N-3-amino-2- hydroxypropanal and it is confirmed that alcohol dehydrogenase from horse liver is the most efficient catalyst for this reaction step. Aldol addition is catalyzed by D-fructose 6- phosphate aldolase as the most appropriate catalysts for this reaction, according to the literature. Since alcohol dehydrogenase requires a coenzyme for its activity, the regeneration was done by using NADH oxidase. Coenzyme regeneration has to be fast and efficient to shift the equilibrium of oxidation towards aldehyde synthesis. Therefore, the influence of NADH oxidase and alcohol dehydrogenase activity ratio was tested on alcohol conversion in a cascade reaction. Also, the influence of coenzyme concentration and initial substrate (amino alcohol) concentration on the cascade reaction product yield was examined. The operational stability of all enzymes was determined by following their activity during the experiments.

enzymatic cascade reactions, imino sugars, aldol addition

nije evidentirano