摘要分子量是聚合物的重要特性之一, 木质素的分子量及其分布是研究苯丙烷类结构的反应、物理化学特性和评价其改性产物质量的内容之一。本研究以陆地棉TM-1成熟纤维为材料, 分别利用酶解-温和酸解木质素法和二氧六环法提取棉纤维中木质素, 结合凝胶渗透色谱法(gel permeation chromatography, GPC)调查和评价2种方法获得的棉纤维中木质素的相对分子量。结果表明, 经二氧六环处理提取的棉花纤维中的木质素(dioxane lignin, DL)的重均分子量为2924 g mol-1、数均分子量2403 g mol-1, 略高于由酶解-温和酸解处理提取的木质素(enzymatic hydrolysis-mild acidolysis lignin, EMAL)的重均分子量(2169 g mol-1)和数均分子量(1970 g mol-1), EMAL的多分散系数稍低, 说明木质素的均一性比DL高。表明EMAL法提取的木质素更适用于分析棉纤维中木质素的相对分子量。利用EMAL法分析棉纤维中木质素相对分子量表明, 不同棉花品种的木质素重均分子量分布范围为938~2169 g mol-1, 数均分子量分布范围为857~1970 g mol-1, 多分散性系数在1.09~1.74间, 均小于2。重均分子量与纤维马克隆值呈显著负相关, 数均分子量与纤维长度呈显著负相关, 与纤维马克隆值呈极显著负相关。
关键词:棉花纤维; 木质素; 相对分子量; 酶解-温和酸解; 凝胶渗透色谱 Relative Molecular Weight of Lignin in Cotton Fiber HU Wen-Ran, FAN Ling, LI Xiao-Rong, XIE Li-Xia, YANG Yang, LI Bo, CHEN Fang-Yuan Xinjiang Key Laboratory of Crop Biotechnology / Laboratory of Molecular Mechanism and Molecular Breeding in Cotton of Xinjiang Academy of Agricultural Sciences / Biotechnology Institute of Nuclear Technology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China Fund:This study was supported by the Key Laboratory Projects of Xinjiang Uygur Autonomous Region (2016D03013) and the Talents Engaging in Scientific and Technological Innovations of Xinjiang (2014721025) AbstractMolecular weight is one of the important characteristics of polymers, lignin molecular weight and its distribution is one of the contents for studying responses of phenylpropanoid structure, physicochemical characteristics and evaluation of the modified product quality. In this research, the relative molecular weight of lignin extracted respectively by enzyme hydrolysis mild acidolysis and dioxane from mature cotton fibers ( Gossypium hirsutum L. acc. TM-1) was studied combined with gel permeation chromatography (GPC). The dioxane lignin (DL) had an average molecular weight (Mw) of 2924 g mol-1, and a number-average molecular weight (Mn) of 2403 g mol-1, which were slightly higher than the enzymatic hydrolysis-mild acidolysis lignin (EMAL, Mw was 2169 g mol-1 and Mn was 1970 g mol-1). The polydispersity coefficient of EMAL was slightly lower than that of DL, showing the higher uniformity in EMAL than in DL. The method of EMAL was more suitable to analyze the relative molecular weight of lignin in cotton fiber. The relative molecular weights of lignin in different cotton varieties, extracted by EMAL, were analyzed, showing that the Mw distribution range of lignin was 938-2169 g mol-1, while Mn was 857-1970 g mol-1 and the polydispersity coefficient was 1.09-1.74 (less than 2). The weight average molecular weight had significantly negative correlation with the micronaire value ( P<0.05). The number average molecular weight was negatively correlated with fiber length ( P<0.05), and the micronaire value ( P<0.01), respectively.
Keyword:Cotton fiber; Lignin; Relative molecular weight; Enzymatic hydrolysis-mild acidolysis; Gel Permeation Chromatography (GPC) Show Figures Show Figures
图1 二氧六环处理与酶解温和酸解处理得到的TM-1棉纤维木质素的色谱图Fig. 1 Chromatogram of lignin from TM-1 cotton fiber treated by dioxane and enzyme hydrolysis mild acidolysis
表1 Table 1 表1(Table 1)
表1 二氧六环处理与酶解温和酸解处理得到的TM-1棉纤维木质素的分子量及分布 Table 1 Molecular weight and distribution of lignin from cotton fiber treated by dioxane and enzyme hydrolysis mild acidolysis
表1 二氧六环处理与酶解温和酸解处理得到的TM-1棉纤维木质素的分子量及分布 Table 1 Molecular weight and distribution of lignin from cotton fiber treated by dioxane and enzyme hydrolysis mild acidolysis
2.2 棉纤维中酶解温和酸解木质素相对分子量从图2可以看到不同品种棉纤维中木质素色谱图检测器响应曲线稍有不同。由表2可知, 4个品种棉花纤维中木质素样品重均分子量分布范围为938~2169 g mol-1, 数均分子量分布范围为857~1970 g mol-1, 多分散性系数(Mw/Mn)在1.10~1.74之间。 图2 Fig. 2
表3 不同品种棉纤维EMAL分子量与纤维品质指标间的相关性 Table 3 Correlation coefficient between molecular weight of EMAL and the fiber quality indexes from different cotton varieties
相关系数 Correlation coefficient
重均分子量(X1) Molecular weight
数均分子量(X2) No. average molecular weight
多分散性系数(X3) Polydispersity coefficient
纤维长度(X4) Fiber length
强度(X5) Fiber strength
马克隆值(X6) Micronaire
重均分子量(X1) Molecular weight
1
数均分子量(X2) No.average molecular weight
0.846
1
多分散性系数(X3) Polydispersity coefficient
0.328
-0.225
1
纤维长度(X4) Fiber length
-0.519
-0.882*
0.615
1
强度(X5) Fiber strength
-0.234
-0.523
0.497
0.778
1
马克隆值(X6) Micronaire
-0.933*
-0.978* *
0.027
0.791
0.483
1
* Significant at the 0.05 probability level. * * Significant at the 0.01 probability level. * 表示差异在0.05水平上显著, * * 表示差异在0.01水平上显著。
表3 不同品种棉纤维EMAL分子量与纤维品质指标间的相关性 Table 3 Correlation coefficient between molecular weight of EMAL and the fiber quality indexes from different cotton varieties
FanL, Shi WJ, Hu WR, Hao XY, Wang DM, YuanH, Yan H Y. Molecular and biochemical evidence for phenylpropanoid synthesis and presence of wall-linked phenolics in cotton fibers. , 2009, 51: 626-637[本文引用:3]
[2]
Gou JY, Wang LJ, Chen SP, Hu WL, Chen XY. Gene expression and metabolite profiles of cotton fiber during cell elongation and secondary cell wall synthesis. , 2007, 17: 422-434[本文引用:1]
[3]
Han LB, Li YB, Wang HY, Wu XM, Li CL, LuoM, Wu SJ, Kong ZS, PeiY, Jiao GL, Xia G X. The dual functions of WLIM1a in cell elongation and secondary wall formation in developing cotton fibers. , 2013, 25: 4421-4438[本文引用:3]
[4]
Shi YH, Zhu SW, Mao XZ, Feng JX, Qin YM, ZhangL, ChengJ, Wei LP, Wang ZY, Zhu Y X. Transcriptome profiling, molecular biological, and physiological studies reveal a major role for ethylene in cotton fiber cell elongation. , 2006, 18: 651-664[本文引用:1]
MousaviounP, DohertyW. Chemical and thermal properties of fractionated bagasse soda lignin. , 2010, 31: 52-58[本文引用:1]
[9]
崔朋, 方红霞, 吴强林, 钱晨. 超高效聚合物色谱法测定酚化解聚木质素的相对分子质量. , 2015, 33: 314-317CuiP, Fang HX, Wu QL, Qian C. Relative molecular mass determination of phenolated depolymerized sodium lignosulfonate by advanced polymer chromatography system. , 2015, 33: 314-317 (in Chinese with English abstract)[本文引用:1]
[10]
JeongH, ParkJ, KimS, LeeJ, AhnN, Roh H G. Preparation and characterization of thermoplastic polyurethanes using partially acetylated kraft lignin. , 2013, 14: 1082-1093[本文引用:2]
[11]
PouteauC, DoleP, CathalaB, AverousL, Boquillon N, 2003, 81: 9-18[本文引用:2]
韩敏. 不同提取方法对木质素分子量及其分布的影响. , 2013, 23: 1-4HanM. Effects of different extraction on lignin molecular mass and distribution. (), 2013, 23(2): 1-4 (in Chinese with English abstract)[本文引用:3]
[14]
孙永昌. 木质素高效分离、结构表征及基于离子液体的降解机理研究. 北京林业大学博士学位论文, , 2014. pp 125-135Sun YC. Efficient Separation and Structural Characterization of Lignin, and Lignin Degradation in Ionic Liquid-Based Systems. PhD Dissertation of Beijing Forestry University, Beijing, , 2014. pp 125-135 (in Chinese with English abstract). [本文引用:1]
[15]
Hu WR, FanL, Tian XL, Tian XL. Modified methods for the analysis of the lignin-like phenolic polymer contents of cotton fiber. , 2015, 25: 232-239[本文引用:1]
[16]
胡文冉, 范玲, 孙涛, 谢丽霞, 田晓莉. 结构单体的检测方法. , 2016, 28: 407-412Hu WR, FanL, SunT, Xie LX, Tian X . A method for detecting phenylpropanoid monomers in cotton fiber. , 2016, 28: 407-412 (in Chinese with English abstract)[本文引用:1]
[17]
胡文冉, 范玲, 谢丽霞, 王乐乐. 不同发育阶段棉纤维中木质素的沉积变化. , 2016, 53: 467-472Hu WR, FanL, Xie LX, Wang L L. Dynamic changes of lignin deposition during cotton fiber development stage. , 2016, 45: 467-472 (in Chinese with English abstract)[本文引用:1]
[18]
MüseG, SchindlerT, BergfeldR, RuelK, JacquetG, LapierreC, SpethV, SchopferP. Structure and distribution of lignin in primary and secondary cell walls of maize coleoptiles analyzed by chemical and immunological probes. , 1997, 201: 146-159[本文引用:1]
[19]
KodaK, GasparA, Argyropoulos DS. Molecular weight- functional group relations in softwood residual kraft lignins. , 2005, 59: 612-619[本文引用:1]
[20]
Wu SB, Argyropoulos DS. An improved method for isolating lignin in high yield and purity. , 2003, 29: 235-240[本文引用:1]
[21]
蒋挺大. . 北京: 化学工业出版社, 2008Jiang TD. Beijing: Chemical Industrial Press, 2008 (in Chinese)[本文引用:3]
[22]
胡文冉, 张芳, 白洁, 曹双瑜, 范玲. 有机溶剂法提取棉花纤维中木质素. , 2011, 48: 1701-1703Hu RW, ZhangF, BaiJ, Cao SY, FanL. Extraction of lignin from cotton fiber with organic solvents. , 2011, 48: 1701-1703 (in Chinese with English abstract)[本文引用:1]
[23]
IkedaT, HoltmanK, Kadla JF, Chang HM, JameelH. Studies on the effect of ball milling on lignin structure using a modified DFRC methods. , 2002, 50: 129-135[本文引用:1]
[24]
刘凤岐, 汤心颐. 高分子物理. 北京: 高等教育出版社, 1995. pp 15-18Liu FQ, Tang X Y. Beijing: High Education Press, 1995. pp 15-18(in Chinese)[本文引用:1]
[25]
中野準三. . 北京: 轻工业出版社, 1988. pp 320-334NakanoJ. Beijing: China Light Industry Press, 1988. pp 320-334(in Chinese)[本文引用:1]
[26]
BjörkmanA. Studies on finely divided wood: I. Extraction of lignin with neutral solvents. , 1956, 59: 477-485[本文引用:1]
[27]
Brownell HH. Isolation of milled lignin and lignin carbohydrate complex. , 1965, 48: 513-518[本文引用:1]
[28]
GuerraA, FilpponenI, Lucia LA, Argyropoulos. Comparative evaluation of three lignin isolation protocols for various wood species. 2006, 54: 9696-9705[本文引用:1]
[29]
武书斌, 李梦实. 麦草酶解-温和酸解木质素的化学结构特性研究. , 2006, 26(1): 104-108Wu SB, Li MS. Study on chemical structure characteristics of wheat straw lignin from enzymatic hydrolysis-mild acidolysis. , 2006, 26: 104-108 (in Chinese with English abstract)[本文引用:1]