During the pretreatment of biomass, the research on the migration process of lignin in the cell wall and the change of chemical structure is very important for improving pretreatment and subsequent lignin upgrading. Hence, corn stalk lignin was extracted by 1, 4-dioxane organosolv system under mild conditions with varying pretreatment time and 0.1 M hydrochloric acid as catalyst. The heterogeneity of lignin removal in the different morphological areas of the cell wall was revealed by advanced imaging techniques. Results indicated that during the pretreatment with dioxane organosolv, the removal of lignin started from the secondary wall of the cell wall, and gradually developed outward to the compound middle lamella. Meanwhile, the resulting lignin obtained through different pretreatment times was characterized by two-dimensional heteronuclear single quantum coherence spectroscopy (2D-HSQC) and gel permeation chromatography (GPC). These characterization results indicated that there were more syringyl (S) units in the lignin that were removed first, and the proportion of guaiacyl (G) units was increased as the pretreatment continued. All the evidence supports the idea that the main reason for the significant differences in lignin structures at various periods of the lignin removal process is that the lignin come from different cell wall regions.

在生物质预处理过程中，研究木质素在细胞壁中的迁移过程和化学结构的变化，对于改进预处理和后续木质素的升级改造具有重要意义。因此，采用 1, 4-二恶烷有机溶剂体系在温和条件下以 0.1 M 盐酸为催化剂，以不同的预处理时间提取玉米秸秆木质素。先进的成像技术揭示了细胞壁不同形态区域木质素去除的异质性。结果表明，在二氧六环有机溶剂预处理过程中，木质素的去除从细胞壁的次生壁开始，逐渐向外发展到复合中层。同时，采用二维异核单量子相干光谱（2D-HSQC）和凝胶渗透色谱（GPC）对不同预处理时间得到的木质素进行了表征。这些表征结果表明，木质素中首先去除的紫丁香基 (S) 单元较多，随着预处理的继续，愈创木脂基 (G) 单元的比例增加。所有证据都支持这样的观点，即在木质素去除过程的不同阶段，木质素结构存在显着差异的主要原因是木质素来自不同的细胞壁区域。随着预处理的继续，愈创木脂基 (G) 单元的比例增加。所有证据都支持这样的观点，即在木质素去除过程的不同阶段，木质素结构存在显着差异的主要原因是木质素来自不同的细胞壁区域。随着预处理的继续，愈创木脂基 (G) 单元的比例增加。所有证据都支持这样的观点，即在木质素去除过程的不同阶段，木质素结构存在显着差异的主要原因是木质素来自不同的细胞壁区域。