Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, PR China; Engineering Research Center of Forestry Biomass Materials and Energy, Ministry of Education, Beijing Forestry University, Beijing 100083, PR China.
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, PR China; Engineering Research Center of Forestry Biomass Materials and Energy, Ministry of Education, Beijing Forestry University, Beijing 100083, PR China.
Int J Biol Macromol. 2023 Jun 1;239:124256. doi: 10.1016/j.ijbiomac.2023.124256. Epub 2023 Mar 29.
The search for feedstock of catechyl lignin (C-lignin) is great interest and importance, as C-lignin featuring homogeneity and linearity is considered as an "ideal lignin" archetype for valorization and exits in only a few plant seed coats. In this study, naturally occurring C-lignin is first discovered in the seed coats of Chinese tallow, which has the highest content of C-lignin (15.4 wt%) as compared with other known feedstocks. An optimized extraction procedure by ternary deep eutectic solvents (DESs) enables the complete disassembly of C-lignin and G/S-lignin coexisted in Chinese tallow seed coats, and characterizations revealed that the as-separated C-lignin sample is abundant in benzodioxane units with no observation of β-O-4 structures from G/S-lignin. Catalytic depolymerization of C-lignin results in a simplex catechol product in 129 mg per gram seed coats, being higher than other reported feedstocks. Derivatizing the "black" C-lignin via the nucleophilic isocyanation of benzodioxane γ-OH leads to a "whitened C-lignin" with uniform laminar structure and excellent crystallization ability, being conducive to fabricating functional materials. Overall, this contribution showed that Chinses tallow seed coats are suitable feedstock for acquiring C-lignin biopolymer.
寻找儿茶素木质素 (C-木质素) 的原料具有重要意义，因为 C-木质素具有均一性和线性结构，被认为是一种“理想木质素”原型，可用于增值，而且只存在于少数植物种皮中。在这项研究中，首次在乌桕种子种皮中发现了天然存在的 C-木质素，与其他已知原料相比，其 C-木质素含量最高 (15.4wt%)。通过三元深共晶溶剂 (DESs) 优化的提取程序，可以完全拆卸乌桕种子种皮中存在的 C-木质素和 G/S-木质素，特性分析表明，分离得到的 C-木质素样品富含苯并二恶烷单元，没有观察到来自 G/S-木质素的 β-O-4 结构。C-木质素的催化解聚导致每克种皮可获得 129mg 的简单儿茶酚产物，高于其他报道的原料。通过苯并二恶烷 γ-OH 的亲核异氰化反应对“黑色”C-木质素进行衍生化，得到具有均匀层状结构和优异结晶能力的“白化 C-木质素”，有利于制备功能性材料。总的来说，这项研究表明乌桕种子种皮是获取 C-木质素生物聚合物的合适原料。
