Effect of pH on the formation of benzyl ester bonds between glucuronic acid and dehydrogenation polymer

The effect of pH on the addition reaction glucuronic acid to quinone methides generated in synthesis dehydrogenation polymer (DHP or artificial lignin) was investigated. DHP-glucuronic complexes were formed during DHP polymerization catalyzed by a mixture laccase, β-glucosidase, and O2 within range 7 4 presence coniferin as precursor. structure product content benzyl ester bonds characterized Fourier transform infrared spectroscopy, solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance ion chromatography, high performance liquid elemental analysis. results showed that system had an important role formation bonds. Acidic conditions favored methide intermediates with carboxyl groups biosynthesis DHP. However, weakly acidic (pH 6) enhanced glucose. In neutral conditions, DHP-protein complex can be efficiently synthesized amino acids protein.