Structure and identification of immune fragments of acid-degraded oligosaccharides from active Astragalus polysaccharides APS-Ⅱ
10.16438/j.0513-4870.2021-0545
- VernacularTitle:黄芪活性多糖APS-II的酸降解及其降解寡糖的结构和免疫活性研究
- Author:
Li-xia SHI
1
,
2
,
3
;
Ke LI
1
,
2
,
3
,
4
;
Si-ming JIAO
5
;
Lian-jie CUI
1
,
2
,
3
;
Xue-mei QIN
1
,
2
,
3
;
Yu-guang DU
5
;
Zhen-yu LI
1
,
2
,
3
;
Xiao-xia LI
6
Author Information
1. Modern Research Center for Traditional Chinese Medicine of Shanxi University, Taiyuan 030006, China
2. Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education of Shanxi University, Taiyuan 030006, China
3. Key Laboratory of Effective Substances Research and Utilization in TCM of Shanxi Province, Taiyuan 030006, China
4. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
5. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
6. Shanxi Fruit Industry Work Station, Taiyuan 030001, China
- Publication Type:Research Article
- Keywords:
APS-Ⅱ;
partial acid hydrolysis;
mass spectrometry analysis;
separate preparation;
immune activity evaluation
- From:
Acta Pharmaceutica Sinica
2021;56(8):2266-2275
- CountryChina
- Language:Chinese
-
Abstract:
We previously reported that active Astragalus polysaccharides APS-Ⅱ generate strong immune activity. Here we establish the optimal method for APS-II acid degradation. After preliminary structural studies and separation and preparation of the degradation products, the oligosaccharide active center with the strongest immune activity was identified by in vitro immune cell culture experiments. The optimum acid degradation conditions for APS-II were determined by a single factor experiment and an orthogonal experiment. Astragalus oligosaccharides prepared under the optimal conditions were subjected to structural analysis by hydrophilic interaction chromatography - electrospray ionization source - high resolution time-of-flight mass spectrometry. The products were separated and oligosaccharide fragments with different degrees of polymerization were isolated by preparative purification chromatography. Finally, fragments of the immunologically active centers were identified by in vitro immune cell cultures from multiple perspectives. The results show that the optimal acid hydrolysis conditions for APS-Ⅱ are hydrolysis temperature 80 ℃, trifluoroacetic acid concentration 1.0 mol·L-1, hydrolysis time 1 h. The degradation conditions have good repeatability. The degradation product is a six-carbon aldehyde glycan structure with the main chain 1→4 connected. The immune activity screening experiment for six oligosaccharide fragments showed that larger molecular weight oligosaccharides have stronger immune-promoting effects. It is speculated that the immunologically active center of Astragalus oligosaccharide is located in the sugar chain of DP9-DP19. The animal welfare and the experimental process in this study follow the requirements of the Animal Ethics Committee of Shanxi University. This result suggests a foundation for the structural characterization and structure-activity relationship research of Astragalus oligosaccharides, and may promote the development of Astragalus oligosaccharide drugs.
