The lignin dehydrogenation polymers(DHP) were prepared using lignin precursor isoeugenol as raw material and laccase as catalyst. The structure of DHP was characterized by FT-IR, 13C NMR spectroscopy and GPC. The antioxidant activity of DHP was also studied by investigating the effect of the product on the half inhibitory concentration(IC50) of diphenyl picrylhydrazyl radical (DPPH·) and on retarding the oxidation of β-carotene. The results showed that the structure of DHP was similar to the Ginkgo milled wood lignin (MWL). The 13C NMR spectrum showed that the typical lignin substructures such as β-5,β-O-4,β-1,β-β exist in the DHP. The content of free phenolic hydroxyl in DHP decreased with the increase of molecular weight. After classification,it was found that the ether-soluble fraction (DHP①) had the best antioxidant properties. The IC50 value of this fraction was only 0.12 g/L. The increase of the volume or concentration of DHP could improve the ability of inhibition of oxidation of β-carotene.%以木质素前驱物异丁香酚为原料,漆酶催化合成得到木质素脱氢聚合物(DHP),利用凝胶渗透色谱(GPC)、红外光谱(FT-IR)和核磁共振(13C NMR)对DHP的结构进行表征,并通过考察产物对二苯基苦基苯肼自由基(DPPH·)的半数抑制质量浓度(IC50),以及对延缓β-胡萝卜素氧化的效果来探讨DHP的抗氧化性能.研究表明:在漆酶的催化作用下异丁香酚脱氢聚合形成的DHP在主要化学结构上与银杏磨木木质素(MWL)非常相似,13C NMR谱表明DHP中存在β-5、β-O-4、β-1、β-β等典型木质素结构.DHP中游离酚羟基含量随相对分子质量增加而降低,分级后发现溶于乙醚的DHP组分(DHP①)的抗氧化性能最好,其半数抑制质量浓度(IC50)仅为0.12 g/L,增加DHP溶液的体积或浓度都能提高其对β-胡萝卜素氧化的抑制效果.
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