Fractionation of lignin-carbohydrate complexes by hydrophobic-interaction chromatography

Hydrophobic properties of lignin-carbohydrate complexes (LCC) isolated from Pinus densiflora Sieb. et Zucc. have been analysed by hydrophobic-interaction chromatography on Phenyl- and Octyl-Sepharose CL-4B gels. The ability of LCC to be adsorbed by these hydrophobic gels was exclusively dependent on their lignin content. Materials adsorbed on Octyl-Sepharose were desorbed with a lower concentration of 2-ethoxyethanol than those adsorbed on Phenyl-Sepharose. In the adsorption of LCC by Phenyl-Sepharose, ππ interactions between the aromatic ligands and the benzene skeletons of lignin play an important role, whereas hydrophobic interaction is the exclusive driving-force for adsorption in the case of Octyl-Sepharose.