Ren Hao, Tian Wenyuan, Shu Fan, Xu Dongliang, Fu Chunxiang, Zhai Huamin
Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology, Nanjing Forestry University, No.159, Longpan Rd., Xuanwu District, Nanjing 210037, China.
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Science, Qingdao 266101, China.
Polymers (Basel). 2018 Jul 2;10(7):727. doi: 10.3390/polym10070727.
Cafferic acid--methyltransferases (COMT) down-regulated transgenic and wild-type switchgrass were separated into lignocresols (LCs) and sugars by a phase separation method involving 72% sulfuric acid and cresol. The isolated LCs were characterized by FTIR, GPC, ¹H NMR and 2D-HSQC to understand potential structural modification caused by transgenic engineering lignin or phase separation treatment. No significant changes were found in terms of molecular weights and the amount of incorporated -cresols between transgenic and wild-type switchgrass LCs. However, the compositions, ratios of syringyl (S) units to guaiacyl (G) units, were changed significantly leading to decrease in S units and increase in G units for transgenic switchgrass LC. The benzodioxane structures and 5-hydroxyguaiacyl units were observed in the 2D-HSQC implied that 5-hydroxyconiferyl alcohol was incorporated into lignin as a result of COMT-down-regulation in the transgenic process.
通过一种涉及72%硫酸和甲酚的相分离方法，将咖啡酸-O-甲基转移酶（COMT）下调的转基因柳枝稷和野生型柳枝稷分离为木质甲酚（LCs）和糖类。通过傅里叶变换红外光谱（FTIR）、凝胶渗透色谱（GPC）、核磁共振氢谱（¹H NMR）和二维异核单量子相干谱（2D-HSQC）对分离得到的LCs进行表征，以了解转基因工程木质素或相分离处理引起的潜在结构修饰。转基因柳枝稷和野生型柳枝稷的LCs在分子量和掺入的甲酚量方面没有发现显著变化。然而，其组成，即紫丁香基（S）单元与愈创木基（G）单元的比例发生了显著变化，导致转基因柳枝稷LCs中S单元减少，G单元增加。二维异核单量子相干谱中观察到的苯并二恶烷结构和5-羟基愈创木基单元表明，在转基因过程中，由于COMT下调，5-羟基松柏醇被掺入到木质素中。
