Fig. 2

Heteronuclear single quantum correlation NMR spectra of alkali lignin samples before and after pretreatment. a Untreated alkali lignin, b laccase-pretreated alkali lignin, c LMS-pretreated alkali lignin
Heteronuclear single quantum correlation NMR spectra of alkali lignin samples before and after pretreatment. a Untreated alkali lignin, b laccase-pretreated alkali lignin, c LMS-pretreated alkali lignin