Core Facility Center "Arktika" Northern (Arctic) Federal University named after M.V. Lomonosov, Northern Dvina Emb., 17, Arkhangelsk 163002, Russia.
Int J Biol Macromol. 2020 Dec 1;164:3814-3822. doi: 10.1016/j.ijbiomac.2020.08.240. Epub 2020 Sep 6.
Lignins of non-woody fast-growing plants cause high interest in recent time as a potential source of raw materials for biorefining. Studying of the lignin structure in shrubs will allow obtaining the information about processes of biosynthesis of these plants and developing methods of their delignification for bioprocessing industry. We studied the structure of raspberry dioxane lignin (Rubus idaeus L.) using various spectroscopic methods, including FT-IR and NMR (1D and 2D) for various nuclei. Also, we used gel permeation chromatography and elemental analysis. It is obtained that raspberry dioxane lignin has relatively wide polydispersity, with Mw/Mn = 2.6, and a relatively lower molecular weight (Mw = 5111 g/mol) due to low molecular weight oligolignols. P-NMR spectroscopy allowed to obtain that raspberry lignin belongs to GS-type. Due to C-NMR we calculated hypothetical empirical formula of the studied lignin and determined the substructures and ether bonds content. S/G ratio of lignin is important parameter for delignification process, and it is equal to 1.19 indicating that lignin rich in S-units will easily degrade even under mild alkaline conditions.
近年来，由于非木材速生植物的木质素作为生物炼制原料的潜在来源，引起了人们的极大兴趣。研究灌木木质素的结构可以获得有关这些植物生物合成过程的信息，并为生物加工工业开发它们的脱木质素方法。我们使用各种光谱方法，包括傅里叶变换红外光谱（FT-IR）和 1D 和 2D 核磁共振（NMR），对树莓二氧六环木质素（Rubus idaeus L.）的结构进行了研究。还使用了凝胶渗透色谱和元素分析。结果表明，树莓二氧六环木质素具有相对较宽的多分散性，Mw/Mn = 2.6，分子量相对较低（Mw = 5111 g/mol），这是由于低分子量寡聚木酚的存在。P-NMR 光谱表明，树莓木质素属于 GS 型。通过 C-NMR，我们计算了所研究木质素的假设经验公式，并确定了其结构单元和醚键含量。木质素的 S/G 比是脱木质素过程的一个重要参数，其值为 1.19，表明富含 S 单元的木质素即使在温和的碱性条件下也容易降解。
