Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13068-019-1499-3/MediaObjects/13068_2019_1499_Fig2_HTML.png)
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