棉花纤维中苯丙烷类化合物的沉积及结构研究

发布时间：2018-07-01 14:42

本文选题：棉花纤维 + 苯丙烷类化合物　；参考：《中国农业大学》2016年博士论文

【摘要】：结构物质生化组分是棉花纤维品质形成的基础,现有研究发现棉花纤维中存在着苯丙烷类化合物,并与棉花纤维品质形成有关,但该化合物的化学特性尤其是其结构单体还缺乏研究。棉花纤维纤细、柔软、纤维素含量高,不同于其他植物细胞壁,分析其他植物材料中苯丙烷类化合物的方法不能直接用于棉花纤维。本研究根据棉花纤维的这一特性,优化改良常用的化学处理方法,并利用改良后的方法通过对棉花纤维中苯丙烷类化合物含量动态变化及其结构进行分析,研究棉花纤维中的苯丙烷类化合物的特性,为揭示棉花纤维品质形成的生化机理奠定基础。主要研究结果如下：1.利用荧光显微镜对切断的棉花纤维进行观察,发现在纤维切断的两头有较强的自发荧光,棉花纤维细胞壁中由于有初生壁的包被,使得其在纤维的切头处荧光现象表现明显,这一现象在所观察的棉花纤维中具有普遍性。对棉花纤维采用巯基乙酸法提取苯丙烷类化合物后,其自发荧光现象随着提取次数的增加而减弱,从而揭示苯丙烷类化合物主要存在于棉花纤维次生壁中。2.优化了经典的分析植物细胞壁木质素的Klason法,使其适用于分析棉花纤维这种特殊材料的木质素,并利用优化后的Klason法对不同发育阶段棉花纤维木质素动态积累进行分析,结果表明开花后20天(20DP A,Day Post-anthesis)棉花纤维中木质素的百分含量最大,随着纤维发育,木质素的百分含量呈下降趋势,成熟纤维的木质素百分含量最低。组织化学染色表明发育20 DPA时棉花纤维染色最深,随着棉花纤维的发育,染色越来越浅,直至纤维成熟后染色颜色最浅。再次表明棉花纤维发育20 DPA时木质素百分含量最大,随着棉花纤维发育而下降,根据组织化学染色结果推测棉花纤维中可能存在有G(Guaiacyl unit,愈创木基丙烷单元)和S(Syringyl unit,紫丁香基丙烷单元)两种结构单体。3.建立了适合棉花纤维苯丙烷类结构单体的分析方法：利用巯基乙酸法将苯丙烷类化合物从清洗过可溶物质的干燥的棉花纤维中提取分离出来,用5 mL蒸馏水清洗2次,干燥后用研钵将结集在一起的苯丙烷类化合物研磨成粉末；再采用DFRC(Derivatization Followed by Reductive Cleavage,衍生化后的还原降解反应)法分析得到其结构单体,两种方法结合可以检测到棉花纤维中含有G-木质素和S-木质素组成的两种结构单体,并且G响应值显著高于S。该方法同时为研究苯丙烷类化合物含量低的材料的结构单体提供了新的思路。4.利用巯基乙酸和盐酸处理植物细胞壁,蒸馏水清洗游离的化学试剂后电镜观察、对比分析后发现：巯基乙酸和盐酸预处理可以使细胞壁断裂破碎,但不造成其组分结构破坏,未经化学处理的纤维和提取过苯丙烷类化合物的纤维在1500～1100 cm~(-1)波数区间近似重叠,而巯基乙酸和盐酸处理后的棉花纤维在1730 cm~(-1),1350～1150 cm~(-1)波数区间显著高于未经化学处理的棉花纤维。巯基乙酸和盐酸处理植物细胞壁后再采用FTIR(Fourier Transform Infrared Spectroscopy,傅里叶变换红外光谱分析法)分析,显示了一些非化学处理所观察不到的吸收波峰,使FTIR分析得到的组分结果更加丰富。棉花纤维FTIR分析结果表明,棉花纤维中存在愈创木基和紫丁香基两种结构单元。根据成熟棉花纤维在1270 cm~(-1)和1230 cm~(-1)处吸收峰的强度比A1270/Ai230=1.69,推知棉花纤维中木质素的类型为愈创木基-紫丁香基木质素(G-S),且愈创木基的相对含量多于紫丁香基。在纤维发育20 DPA时,纤维红外光谱图中大部分吸收峰都比随后的发育进程中的吸收峰高,尤其是在3340 cm~(-1)、2920 cm~(-1)、1730 cm~(-1)、1620 cm~(-1)、1510 cm~(-1)、1430 cm~(-1)、1270 cm~(-1)、1230 cm~(-1)处的吸收峰都比其他发育时期的高,1330 cm~(-1)处的吸收峰在该时期稍低。随着棉花纤维的发育,这些吸收峰值逐渐降低,1330 cm~(-1)处的吸收值升高,而1230 cm~(-1)吸收峰降低。5.利用1H-NMR(Nuclear Magnetic Resonance,核磁共振氢谱)法分析棉花纤维中的木质素可推断棉花纤维木质素属愈创木基-紫丁香基型木质素(G-S型木质素),愈创木基单元和紫丁香基单元间相互连接的方式有：碳-碳键β-5和β-β、醚键β-O-4。
[Abstract]:The biochemical components of structural substances are the basis for the formation of cotton fiber quality. The existing studies have found that there are phenylpropane compounds in cotton fibers, which are related to the formation of cotton fiber quality, but the chemical properties of the compound, especially the structural monomers, are still lack of study. Cell wall, analysis of phenylpropane compounds in other plant materials can not be used directly in cotton fiber. This study, based on the characteristics of cotton fiber, optimized the modified methods of chemical treatment, and analyzed the dynamic changes and structure of the benzopropane content in cotton fiber by the improved method. The characteristics of the phenylpropane compounds in cotton fiber lay the foundation for revealing the biochemical mechanism of the cotton fiber quality formation. The main results are as follows: 1. the cotton fibers cut off were observed by the fluorescence microscope, and the strong spontaneous fluorescence was found on the two ends of the fiber, and the wall of the cotton fiber cell was due to the primary wall. The phenomenon of fluorescence in the cutting head of the fiber is obvious. This phenomenon is common in the observed cotton fibers. After the extraction of propane compounds by mercapto acetic acid, the spontaneous fluorescence phenomenon of cotton fiber decreases with the increase of the number of extraction times, thus revealing that the phenylpropane compounds are mainly in cotton. In the secondary wall of the flower fiber,.2. optimized the classical Klason method for analyzing the lignin of plant cell wall, making it suitable for analyzing the lignin of the special material of cotton fiber, and using the optimized Klason method to analyze the dynamic accumulation of cotton fiber lignin at different developmental stages. The results showed that 20 days after flowering (20DP A, Day Post-anthesis). The percentage of lignin in cotton fiber is the largest. With the development of fiber, the content of lignin is decreasing and the percentage of lignin in mature fiber is the lowest. The histochemical staining shows that cotton fiber is dyed the most when the development of 20 DPA, with the development of cotton fiber, the color is getting lighter and shallower, and the dyeing color is the shallower after the fiber matures. It was shown that the content of lignin was the largest in cotton fiber development at 20 DPA and decreased with the development of cotton fiber. According to the histochemical staining results, it is suggested that there may be two kinds of structural monomer.3. for cotton fiber in cotton fiber, including G (Guaiacyl unit, guaiaco propane unit) and S (Syringyl unit, purple Ding Xiangji propane unit). A method for the analysis of the structural monomers of the type of vitamin benzoate: extraction of phenylpropane compounds from the dry cotton fibers that cleaned the soluble substances by mercapto acetic acid, cleaned with 5 mL distilled water for 2 times, and then grinded into the powder by the mortar, and then using the DFRC (Derivatization Follo). Wed by Reductive Cleavage, derived reductive degradation reaction) method was used to analyze the structural monomers. Two methods were used to detect two structural monomers containing G- lignin and S- lignin in cotton fibers, and the G response value was significantly higher than that of S.. The structure monomer provides a new idea.4. using mercapto acetic acid and hydrochloric acid to treat plant cell wall, distilled water to clean free chemical reagents after scanning electron microscope. After comparison and analysis, it is found that mercapto acetic acid and hydrochloric acid pretreatment can break the cell wall fracture, but do not cause its component structure broken, without chemically treated fiber and extraction of phenylpropyl The fibers of Alkane Compounds overlapped approximately in the range of 1500~1100 cm~ (-1) wave numbers, while mercapto acetic acid and hydrochloric acid treated cotton fibers were significantly higher in the 1730 cm~ (-1), 1350~1150 cm~ (-1) wave numbers than those of untreated cotton fibers. Mercapto acetic acid and hydrochloric acid were used to treat the cell wall of plants and then FTIR (Fourier Transform Infrared S) Pectroscopy, Fourier transform infrared spectroscopy (FTIR) analysis showed that some non chemical absorption peaks were not observed, and the results of FTIR analysis were more abundant. Cotton fiber FTIR analysis showed that there were two structural units of guaiaci and clove base in cotton fiber. According to the mature cotton fiber in 1270 C The intensity of the absorption peak at m~ (-1) and 1230 cm~ (-1) is higher than that of A1270/Ai230=1.69. It is known that the type of lignin in cotton fiber is the guaiac-clove based lignin (G-S), and the relative content of the guaiaci base is more than the clove base. When the fiber development is 20 DPA, most of the absorption peaks in the fiber infrared spectrum are compared to the absorption in the subsequent development process. Peak height, especially at 3340 cm~ (-1), 2920 cm~ (-1), 1730 cm~ (-1), 1620 cm~ (-1), 1510 cm~ (-1), 1430 cm~ (-1), 1270, 1230, is higher than the other development period, and the absorption peak at 1330 is slightly lower at this time. With the development of cotton fiber, these absorption peaks gradually decrease, 1330 absorbed absorption The value of the 1230 cm~ (-1) absorption peak decreased.5. and the 1H-NMR (Nuclear Magnetic Resonance, NMR) method was used to analyze the lignin of cotton fiber Lignin - guaiacl - clove based lignin (G-S type lignin), and the connection between the guaiaci base unit and the clove units was carbon - Carbon bond beta -5 and beta - beta, ether bond beta -O-4.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S562

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