Enzymatic synthesis of vanillin.
Due to increasing interest in natural vanillin, two enzymatic routes for the synthesis of vanillin were developed. The flavoprotein vanillyl alcohol oxidase (VAO) acts on a wide range of phenolic compounds and converts both creosol and vanillylamine to vanillin with high yield. The VAO-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol is further oxidized to vanillin. Catalysis is limited by the formation of an abortive complex between enzyme-bound flavin and creosol. Moreover, in the second step of the process, the conversion of vanillyl alcohol is inhibited by the competitive binding of creosol. The VAO-catalyzed conversion of vanillylamine proceeds efficiently at alkaline pH values. Vanillylamine is initially converted to a vanillylimine intermediate product, which is hydrolyzed nonenzymatically to vanillin. This route to vanillin has biotechnological potential as the widely available principle of red pepper, capsaicin, can be hydrolyzed enzymatically to vanillylamine.
van den Heuvel
R H
RH
Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
Fraaije
M W
MW
Laane
C
C
van Berkel
W J
WJ
D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000975:Antioxidants / Q000138:chemical synthesis; D001547:Benzaldehydes / Q000138:chemical synthesis*; D007700:Kinetics
D000975:Antioxidants; D001547:Benzaldehydes; C100058:vanillin; D000429:Alcohol Oxidoreductases; C076865:vanillyl-alcohol oxidase