An aldehyde derivative of riboflavin was covalently attached by reductive alkylation to soluble polycationic supports. The flavopolymers so obtained were stable under operational conditions. The catalytic efficiency towards oxidation of NADH by these flavopolymers was demonstrated, and the kinetic parameters ( K , and k,,,) revealed an overall catalytic efficiency (k,,,/K,) 185-fold greater compared to riboflavin.Various factors affecting the chemical regeneration of NAD' from NADH such as pH, ionic strength, nature of the buffer etc. were studied. The most interesting result was the highly favourable influence of borate ions which increased the reaction rate by a factor 2 -4 compared to the other buffers.The flavopolymers are very effective for in situ recycling of NAD(P)+. With up to 300-fold NADH + NAD' conversions for the system using yeast alcohol dehydrogenase and up to 1500-fold NADPH + NADP' regenerations for the system using glucose-6-phosphate dehydrogenase. These flavopolymers are superior to previous chemical recycling systems.Enzyme technology has proved its economic and industrial potential by the successful development of a 'first generation' of enzymes such as hydrolases and isomerases, which do not require coenzymes.A new objective is now to develop what are already called the 'second generation' of enzyme reactors which catalyze the synthesis and the modification of the fine chemicals of high added value. These processes are mainly oxido-reduction reactions, and thus involve the use of enzymes requiring expensive coenzymes which are needed in stoichiometry amounts. Any economically feasible process will thus depend on the retention or recovery and the regeneration of the coenzymes. Regeneration of coenzymes required for oxidoreduction reactions has been accomplished mainly by enzymatic methods [1] rather than by non-enzymatic methods.The chemical methods of regenerating coenzymes have received less attention than the enzyme-dependent processes although their advantages are stability and low cost of re-
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.