1. Structure-activity relationship of low molecular weight Astragalus membranaceus polysaccharides produced by Bacteroides.
- Author
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Cai Y, Si Z, Jiang Y, Ye M, Wang F, Yang X, Yu J, Gao X, and Liu W
- Subjects
- Molecular Weight, Toll-Like Receptor 4, Galactose, Bacteroides, Polysaccharides pharmacology, Polysaccharides chemistry, Structure-Activity Relationship, Astragalus propinquus chemistry, Astragalus Plant chemistry
- Abstract
Astragalus membranaceus polysaccharides (APS) possess significant biological activities, such as anti-tumor, antiviral, and immunomodulatory activities. However, there is still a lack of research on the structure-activity relationship of APS. In this paper, two carbohydrate-active enzymes from Bacteroides in living organisms were used to prepare degradation products. The degradation products were divided into APS-A1, APS-G1, APS-G2, and APS-G3 according to molecular weight. Structural analysis showed that all degradation products had an α-1,4-linked glucose backbone, but APS-A1 and APS-G3 also had branched chains of α-1,6-linked galactose or arabinogalacto-oligosaccharide. In vitro, immunomodulatory activity evaluation results indicated that APS-A1 and APS-G3 had better immunomodulatory activity, while the immunomodulatory activities of APS-G1 and APS-G2 were comparatively weaker. Molecular interaction detection showed that APS-A1 and APS-G3 could bind to toll-like receptors-4 (TLR-4) with a binding constant of 4.6 × 10
-5 and 9.4 × 10-6 , respectively, while APS-G1 and APS-G2 failed to bind to TLR-4. Therefore, the branched chains of galactose or arabinogalacto-oligosaccharide played a crucial role in the immunomodulatory activity of APS., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2023. Published by Elsevier Ltd.)- Published
- 2023
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