| 摘要: |
| 本文采用三检测器联用凝胶色谱法对κ-型、ι-型卡拉胶的分子量进行测量（κ-型、ι-型卡拉胶的分子量分别为685.77 kDa和408.33 kDa）。通过研究两种卡拉胶稀溶液的Mark-Houwink指数、流体力学直径，得出了κ-型和ι-型卡拉胶的分子构象：在低分子量阶段，卡拉胶分子链刚性较强，呈现刚性棒状结构；在中分子量阶段，卡拉胶分子链的刚性降低，构象介于无规线团与刚性棒状结构之间，呈现半刚性的伸展线团；在高分子量阶段，卡拉胶分子呈现出无规线团构象。随着卡拉胶分子量的增加，卡拉胶分子链的刚性逐渐降低，卡拉胶分子由刚性棒状结构变为半刚性延展线团最终变为柔性无规线团，且κ-型和ι-型卡拉胶分子链表现出相同的变化趋势。卡拉胶的分子量和构象对卡拉胶的抗菌抗凝等生物活性以及纺丝性能有着较大的影响，对卡拉胶分子量和构象进行准确分析可以促进卡拉胶在纺织、医药、化妆品等工业生产中的应用。 |
| 关键词: 卡拉胶 多检测器联用凝胶渗透色谱 分子量 构象 |
| DOI：10.11759/hykx20210208007 |
| 分类号:O631 |
| 基金项目:国家自然科学青年基金项目（50803030）；中国博士后科学基金项目（20100471495，201104581）；山东省自然科学基金面上项目（ZR2020ME061）；省部共建生物多糖纤维成形与生态纺织国家重点实验室（青岛大学）基金（ZFZ201810，ZKT17） |
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| Determination of carrageenan molecular weight and dilute solution conformation by tri-detector array gel permeation chromatography |
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HAN Jie, ZHAO Zhi-hui, LIN Yu-feng, XUE Zhi-xin, XIA Yan-zhi
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College of Chemistry and Chemical Engineering, Institute of Marine Biobased Materials, State Key Laboratory of Bio-fibers and Eco-textiles, Qingdao University, Qingdao 266071, China
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| Abstract: |
| This study determined the molecular weights of κ-type and ι-type carrageenan by triple detector array for gel permeation chromatography (the molecular weights of κ-type and ι-type carrageenan were 685.77 kDa and 408.33 kDa, respectively). The molecular conformation of κ-type and ι-type carrageenan was obtained by studying the Mark-Houwink index and hydrodynamic diameter of the two kinds of carrageenan. In the low molecular weight stage, the chain of carrageenan is rigid and presents a rigid rod structure. In the middle molecular weight stage, the rigidity of the carrageenan chain is reduced, and the conformation is between the random coil and the rigid rod-like structure, further presenting a semi-rigid extended structure. At the high molecular weight stage, carrageenan molecules exhibit a random linear conformation. With the increase of molecular weight of carrageenan, the rigidity of the carrageenan molecular chain decreases gradually, and the carrageenan molecular chain changes from a rigid rod structure to a semi-rigid extended structure and finally to a flexible random coil. In fact, the κ-type and ι-type carrageenan molecular chains show a similar trend. The molecular weight and molecular conformation of carrageenan play a crucial role in analyzing the mechanism of action of carrageenan, which can greatly promote the applications of carrageenan in industrial production. |
| Key words: carrageenan TDA-GPC molecular weight conformation |
