【摘要】 为了降低海带多糖LJP61A的分子量，扩大其利用范围，文章分别采用三氟乙酸(TFA)和盐酸(HCl)降解LJP61A,并得到2种酸降解产物DLJP-1和DLJP-2,在此基础上，测定了多糖降解前后的分子量、溶解度、化学组成和三螺旋结构变化；以氧化型低密度脂蛋白(oxidized low density lipoprotein, Ox-LDL)诱导巨噬细胞泡沫化为实验模型，在细胞水平上分析了不同降解处理对LJP61A抑制巨噬细胞泡沫化活性的影响。结果显示：低浓度的TFA和HCl均可有效地降解LJP61A,降低LJP61A的分子量，改善其溶解性；2种降解均未改变LJP61A的主要官能团结构和单糖组成；TFA降解未破坏LJP61A的三螺旋结构，而HCl水解产物中未检测到三螺旋结构。细胞学实验证明：LJP61A酸降解产物对巨噬细胞均无毒性，经过TFA降解后，LJP61A抑制巨噬细胞泡沫化活性显著增强；HCl降解明显降低了LJP61A的活性。研究结果可为海带多糖LJP61A的性能优化和活性改善提供方向，为天然活性多糖的降解开发提供理论基础。更多还原

【Abstract】 The present work aims to decrease the molecular weight and expand the utilization of a Laminaria japonica polysaccharide LJP61A. The trifluoroacetic acid(TFA) and hydrochloric acid(HCl) were employed to degrade LJP61A, and two degradation products, DLJP-1 and DLJP-2, were generated. Based on this, the changes of the molecular weight, solubility, chemical composition, and triple-helix structure of LJP61A after degradation were determined. Additionally, the oxidized low density lipoprotein(Ox-LDL)-induced macrophage foam cell formation was used as the experimental model, and the inhibitory effects of the degradation products on macrophage foam cell formation were clarified at the cellular level. The results revealed that both TFA and HCl at low concentrations could degrade LJP61A effectively with lower molecular weights and higher solubilities. Meanwhile, neither degradation altered the primary functional groups and monosaccharide composition of LJP61A. Moreover, the triple-helix structure of LJP61A remained unaffected by TFA hydrolysis, whereas no triple-helix structure was detected in HCl hydrolysates. At the cellular level, it was demonstrated that the degradation products were nontoxic to RAW264.7 cells, and the inhibitory effects of LJP61A on macrophage foam cell formation increased significantly after TFA hydrolysis. However, the HCl hydrolysis decreased the activity of LJP61A. In conclusion, this research offers a strategy for the performance optimization and activity improvement of LJP61A and provides a theoretical basis for the degradation and development of natural bioactive polysaccharides.更多还原