【作者】 彭湃；

【导师】 孙润仓； 苏印泉；

【作者基本信息】 西北农林科技大学 ， 林产化学加工与工程， 2010， 硕士

【摘要】 竹子作为重要的生物质资源之一,具有分布广、生长快和用途多等特点,在生物质基能源和材料方面拥有较高的利用价值。竹子的化学成分主要为纤维素、半纤维素、木质素和类脂物,研究这些化学成分将对于替代化石资源、节能减排、发展低碳经济和促进农民增收都具有重要意义。本研究（1）采用中等长度高温毛细管柱气相色谱技术对四种竹子（慈竹、硬头黄竹、寿竹和红壳雷竹）甲醇-氯仿（1:1,v/v）抽提物中的脂肪酸、甾醇、蜡、甾醇酯和甘油酸酯等五大组分一步分离出54种化合物,并对其结构进行了表征,同时测定了类脂物中的酚类化合物。（2）采用水、0.5%、1%、1%含60%乙醇、3%、5%和8%NaOH在料液比1:20 g/ml温度60 oC下连续提取脱蜡后红壳雷竹的木质素,对其化学组成进行了研究并表征了结构特征。（3）对研究内容（2）同时提取出来的半纤维素的化学组成和结构进行了研究。该系列研究结果如下:1.类脂物:四种竹子类脂物的主要化学成分为游离脂肪酸（6.49-29.15%）、甘油一酯（0.83-10.50%）、蜡（0.25-4.72%）和甾醇（1.03-3.92%）,此外,还含有一些非酯类化合物:酚类化合物（0.86-4.77%）、杜鹃花酸（0.90-5.95%）和马来酸（0.67-3.12%）以及少量多糖。硬头黄竹的抽提物得率最高（5.98%）,慈竹的得率最低（4.22%）,而寿竹抽提物中类脂物的含量却最高（54.79%）。2.木质素:连续抽提出的木质素总和占原木质素的62.26%,七种木质素组分含有非常低的中性糖（0.01-1.11%）和少量的酯化对香豆酸（0.08-2.37%）和阿魏酸（0-1.69%）以及醚化的对香豆酸（0.02-0.65%）和阿魏酸（0.01-0.27%）,分子量范围在970-3430 g/mol之间。其次,竹子木质素中主要是紫丁香单元,并伴随一定量的愈疮木基单元和少量的对羟基苯基丙烷,单元之间主要以β-O-4键连接,少量的以β-β和β-5连接。3.半纤维素:连续抽提所得半纤维素的总和占原半纤维素的80.1%,分子量在3760-36000 g/mol之间。糖分析研究表明水溶性半纤维素主要成分是葡萄糖而碱溶性半纤维素主要成分是木糖、阿拉伯糖和葡萄糖醛酸。¹H、¹³C NMR和2D-HSQC技术研究表明3%和8%NaOH溶液提取的半纤维素为聚O-乙酰基-4-O-甲基葡萄糖醛酸-阿拉伯糖木糖,并首次鉴定出红壳雷竹碱溶性半纤维素的结构为:→4)[4-O-甲基-α-D-葡萄糖醛酸-（1→2）][2-O-乙酰基][2,3-二-O-乙酰基][α-L-阿拉伯糖-（1→2）] [α-L-阿拉伯糖- （1→3）]-β-D-木糖-(1→。更多还原

【Abstract】 Bamboo as one of the most important biomass resources has the characteristics of wide distribution, fast growth and many applications. It can be used to make materials and energy based on biomass for higher utilization value. The chemical composition of bamboo consists mainly of celluloses, hemicelluloses, lignin and lipophilic. So it is significant to study on the chemical composition for replacement of fossil resources, energy-saving and emission reduction, developing a low-carbon economy, and increaseing the peasants’income. In this paper, （1） The five classes of free fatty, sterols, waxes, steryl esters, and glycerates in lipophilic extractives from the four species of bamboo culms （Sinocalmus affinis （Rendle） Mcclure, B.rihida Keng et Keng f., Phyllostachys bambusoides Sieb. et Zucc. f. shouzhu Yi, and Phyllostachys incarnata Wen） were separated to fifty four individual compounds by GC with a medium-length and high-temperature capillary column. Meanwhile, the structure of lipophilic were further characterized and the content of phenols in lipophilic were determined. （2） The bamboo lignins were obtained by sequential extractions with distilled water, 0.5% and 1% NaOH, 60% ethanol containing 1% NaOH, and 3%, 5% and 8% NaOH with a solid to liquid ratio of 1:20 g/ml at 60 oC for 3 h. Moreover, the chemical composition and structure of lignins were investigated. （3） At the same time, the chemical composition and structure of hemicelluloses from bamboo in process （II） were carried out. All results are reported as follows.1. Lipophilic: free fatty acids （6.49-29.15%）, monoglycerides （0.83-10.50%）, waxes （0.25-4.72%）, and sterols （1.03-3.92%） were the dominant compositions identified in the four species of bamboo culms. In addition, non-lipids determined from the extractives were composed of small amounts of phenolic compounds （0.86-4.77%）, azelaic acid （0.90-5.95%）, maleic acid （0.67-3.12%）, and some quantities of co-extracted polysaccharides. The yield of extractives from B.rihida Keng et Keng f. was the highest and the yield of extractives from Sinocalmus affinis （Rendle） Mcclure was the lowest, while Phyllostachys bambusoides Sieb. et Zucc. f. shouzhu Yi contributed the highest lipophilic content （54.79%）.2. Lignin: the successive extractions together resulted in dissolution of 62.26% original lignins. Seven lignin fractions contained rather low amounts of neutral sugars （0.01-1.11%）, and small amounts of ester-linked p-coumaric （0.08-2.37%） and ferulic acids （0-1.69%） and of ether-linked p-coumaric （0.02-0.65%） and ferulic acids （0.01-0.27%）. The weight-average molecular weights ranged between 970 and 3430 g/mol. Furthermore, the bamboo lignins comprised high amounts of syringyl and noticeable guaiacyl together with small amounts of p-hydroxyphenyl units. Moreover, theβ-O-4 linkage is a major linkage type and small amounts ofβ-βandβ-5 linkages are also present in the lignin molecules.3. Hemicelluloses: the yields of seven fractions together accounted for 80.1% of total available hemicelluloses. The molecular weights of these polymers varied between 3760 and 36000 g/mol. Sugar composition studies showed that the water-soluble hemicelluloses consisted mainly of glucose, while xylose, arabinose and glucuronic acid were the major sugars in alkali-soluble hemicelluloses. Moreover, the structure of the polysaccharides in the two fractions obtained from 3% and 8% NaOH were determined by ¹H, ¹³C NMR spectroscopy and 2D 1H-13C heteronuclear single correlation techniques （HSQC）. It was found that the bamboo hemicelluloses are O-acetyl-（4-O-methylglucurono）-arabinoxylans, and their structural element could be first identified as below:→4)[4-O-Me-α-D-GlcpA-（1→2）][2-O-Ac][2,3-di-O-Ac][α-L-Araf-（1→2）][α-L-Araf-（1→3）]-β-D-Xylp-(1→.更多还原