Polymerization of guaiacol by lignin-degrading manganese peroxidase from Bjerkandera adusta in aqueous organic solvents
2000
Iwahara, K. | Honda, Y. | Watanabe, T. | Kuwahara, M.
Lignin-degrading manganese (II) peroxidase (MnP) purified from the culture of a wood-rotting basidiomycete, Bjerkandera adusta, was used in the polymerization of guaiacol. MnP was found to catalyze polymerization of guaiacol in 50% aqueous acetone, dimethyl formamide, methanol, ethanol, dioxane, acetonitrile, ethylene glycol and methylcellosolve. Maximum yield of polyguaiacol was achieved in 50% aqueous acetone. The weight average molecular weight (M(W)) of the polymer was estimated to be 30 300 by gel permeation chromatography. However, matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF-MS) analysis gave a more reliable M(W) of 1690. IR, 13C-NMR, MALDI-TOF-MS and pyrolysis GC-MS analyses showed the presence of C-C and C-O linkages and quinone structure in polyguaiacol. It was also indicated that polyguaiacol has a methoxy-phenyl group as the terminal moiety. This suggests that polyguaiacol is a branched polymer in which guaiacol units are cross-linked at the phenolic group. Thermal gravimetric and differential scanning calorimetric analyses were also carried out. MnP also catalyzed the polymerization of o-cresol, 2,6-dimethoxyphenol and other phenolic compounds and aromatic amines. M(W) of these polymers ranged from around 1000 to 1500.
显示更多 [+] 显示较少 [-]