P-31 NMR-SPECTROSCOPY IN WOOD CHEMISTRY .5. QUALITATIVE-ANALYSIS OF LIGNIN FUNCTIONAL-GROUPS
P-31 NMR-SPECTROSCOPY IN WOOD CHEMISTRY .5. QUALITATIVE-ANALYSIS OF LIGNIN FUNCTIONAL-GROUPS
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DOI：
10.1080/02773819308020514
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发表时间：
1993-01-01
影响因子：
2
通讯作者：
ARCHIPOV, Y
中科院分区：
文献类型：
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作者：
ARGYROPOULOS, DS;BOLKER, HI;ARCHIPOV, Y
从硬木（桦木、白桦）和软木（黑云杉、云杉）中分离的木质素，通过不同的选择性反应来修饰其官能团。然后用1,3,2-二氧磷酰氯(I)处理所有木质素，并记录其衍生物的P-31 NMR谱。大多数P-31核磁共振信号是由先前从模型化合物中获得的化学位移分配的。对碳水化合物中的不稳定质子、β - o -4结构中的红氧和三氧形式、各种木质素结构中的伯羟基、丁香基和愈创木酰基酚羟基以及羧酸中的不稳定质子衍生产生的信号进行了归类。桦木木质素中β - o -4结构中的α -苯基羟基对烷基化反应的反应比云杉木质素中的α - o -4结构中的α -苯基羟基对烷基化反应的反应弱，这与前人的研究结果一致；这是由于- o -4醚的芳基部分造成的。因此，由1,3,2二磷酰氯衍生的木质素的P-31核磁共振波谱显示出对木质素的结构解析具有相当大的潜力。该方法可用于可溶性木质素的快速分析。
Dioxane lignin isolated from a hardwood (birch, betula verrucosa) and milled wood lignin isolated from a softwood (black spruce, picea mariana) were subjected to a variety of selective reactions to modify some of their functional groups. All the lignins were then treated with 1,3,2-dioxaphospholanyl chloride (I) and the P-31 NMR spectra of the derivatives were recorded. Most of the P-31 NMR signals were assigned from the chemical shifts previously obtained from model compounds. The signals arising from derivatizing the labile protons in carbohydrates, erythro and threo forms in beta-O-4 structures, primary hydroxyls in a variety of lignin structures, syringyl and guaiacyl phenolic hydroxyls and those of carboxylic acids were assigned. The alpha benzylic hydroxyls in beta-O-4 structures within birch lignin were less reactive toward alkylation than those in spruce lignin, consistent with the findings of previous workers; a difference attributable to the aryl part of the beta-O-4 ether. The P-31 NMR spectroscopy of lignins derivatized with 1,3,2 dioxaphospholanyl chloride is thus shown to have considerable potential for the structural elucidation of lignins. This simple method is recommended for the rapid analysis of soluble lignins.