Thioacidolysis of Enzymatic Dehydrogenation Polymers from p-Hydroxyphenyl, Guaiacyl, and Syringyl Precursors
Thioacidolysis of Enzymatic Dehydrogenation Polymers from p-Hydroxyphenyl, Guaiacyl, and Syringyl Precursors
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对羟基苯基、愈创木基和丁香基前体的酶促脱氢聚合物的硫代酸解
DOI：
10.1515/hfsg.1997.51.4.349
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
O. Faix
中科院分区：
文献类型：
--
作者：
G. Jacquet;B. Pollet;C. Lapierre;C. Francesch;C. Rolando;O. Faix
在模拟末端聚合或本体聚合模式的条件下，从对香豆醇、松柏醇和/或芥子醇获得木质素聚合物模型（DHP）。通过硫代酸解和阮内镍脱硫对其结构进行了表征，研究了DHP结构随聚合方式和前驱体类型的变化。不管是什么前兆。添加速率和稀释培养基中单木酚的最终浓度显示出足够的区别性，以产生末端型和本体型DHP。前者模仿不太完美的天然木质素。对羟苯基前体的行为。不太容易被氧化，受到其他类型前体存在的影响。单独聚合时，它会产生高度凝聚的聚合物。相反，当与G和/或S前体共聚时。它有效地参与不稳定的键。在合成的DHP以及天然木质素中，共聚物的H单元主要是具有游离酚基的末端单元。
Lignin polymer models (DHPs) were obtained from p-coumaryl, coniferyl and/or sinapyl alcohols under conditions simulating the end-wise or the bulk polymerization modes. Their structures were characterized by thioacidolysis followed by Raney nickel desulfuration in order to investigate the correlative variations of DHP structures with polymerization mode and precursor type. Whatever the precursors. addition rates and final concentrations of monolignols in the dehydrogenative medium appeared discriminatory enough to give rise to end-wise and bulk type DHPs. the former mimicking less imperfectly native lignins. The behavior of the p-hydroxyphenyl precursor. less easily oxidized, is influenced by the presence of other types of precursors. Polymerized alone, it gives rise to a very condensed polymer. In contrast, when copolymerized with G and/or S precursors. it is efficiently involved in labile bonds. H units of the copolymers are mainly terminal units with free phenolic groups, in synthetic DHPs as well as in native lignins.