Structural features of lignin macromolecules extracted with ionic liquid from poplar wood

► We purified lignin macromolecule from cell wall of poplar wood using ionic liquid ([Emim][CH3COO]) and called to ionic liquid lignin (ILL). ► Structural features of ILL were compared with poplar milled wood lignin (MWL). ► Quantitative amounts of OMe and Phe-OH of ILL were similar to MWL. ► The weight average molecular weight (Mw) of ILL was determined to be 2/3-fold of that of MWL.