Oxidation of lignin-carbohydrate complex from bamboo with hydrogen peroxide catalyzed by Co(salen)

The reactivity of salen complexes toward hydrogen peroxide has been long recognized. Co(salen) was tested as catalyst for the aqueous oxidation of a refractory lignin-carbohydrate complex (LCC) isolated from sweet bamboo (Dendrocalamushamiltonii) in the presence of hydrogen peroxide as oxidant. Co(salen) catalyzed the reaction of hydrogen peroxide with LCC. From the spectra analyses, lignin units in LCC were undergoing ring-opening, side chain oxidation, demethoxylation, ?-O-4 cleavage with Co(salen) catalytic oxidation. The degradation was also observed in the carbohydrate of LCC. The investigation on the refractory LCC degradation catalyzed by Co(salen) may be an important aspect for environmentally-oriented biomimetic bleaching in pulp and paper industry.