FLAVIN-CONTAINING POLYANIONS - SYNTHESIS, ACTIVITY, AND IMMOBILIZATION IN POLYELECTROLYTE COMPLEXES

Linear polymers containing both flavin units and carboxylic acid groups were synthesized by copolymerization of the appropriate styrene derivatives. The catalytic activity of the resulting polyanions in aqueous media was determined for the aerobic oxidation of 1-benzyl-1,4-dihydronicotinamide (BNAH). A 69-fold (maximum) increase of the activity of the flavin moieties was found after binding to the polyanions as compared to a low molar mass analogue, which may be attributed to a higher polarity of the microenvironment of the catalyst and to hydrogen bonding of the flavin units to the carboxylic acid groups. The activity of the polyanions was found to be dependent on the medium pH, with an optimum at pH almost-equal-to 8. Complexation of the polyanions with polycations containing pendent quaternary ammonium groups leads to a small decrease in activity, the effect being larger with a higher charge density of the polycation. The resulting polyelectrolyte complex gel particles are quite stable and can be used in a continuous reaction for many days without loss of activity. Finally, homopolymerization of the flavin-containing monomer resulted in the first "flavin homopolymer".