Table 2.

Structure and structure-activity-relationship of polysaccharide from Astragalus.

Type	Extraction method	Monosaccharide composition	Molecular weight/kDa	Structure characteristics	Function	References
Astragalus	Hot water extraction	All consisted of Ara	40.10 kDa	-	Immunomodulation	(42)
Astragalus	Enzyme-assisted extraction	-	-	-	Anti-oxidation	(43)
Astragalus	Cold water extraction	Fuc: Ara: Gal: Glc: Xyl=0.01: 0.06: 0.20: 1.00: 0.06	12.30 kDa	α-D-pyranoid configuration	Anti-tumor and immunomodulation	(44)
Astragalus	-	Glc: Ara: Rha: Gal=13.90: 8.20: 1.20: 1.00	4.72 kDa	(1 → 4)-D-glucose as the main chain and (1 → 6)-D-glucose linkage as the branch chain	Anti-oxidation	(45)
Astragalus	Hot water extraction	Man: Glc: Xyl: Ara: GlcA: Rha=0.27: 12.83: 1.63: 0.71: 1.04: 0.56	2047.76 kDa	Acidic polysaccharides mainly composed of glucose	Immunomodulation and anti-inflammatory	(46)
Astragalus	Hot water extraction	Rha: GalA: Gal: Glc: Ara=0.14: 0.14: 9.60: 24.04: 1.00	10.00 kDa	A main chain of−2,3)-α-L-Rha-(1 → , → 5)-α-L-Ara-(1 → , → 3,4)-β-D-Gal-(1 → , → 6)-β-D-Gal-(1 → , → 4)-α-D-Glu-(1 → , → 3,4,6)-β-D-Glu-(1 →	Immunomodulation	(47)
Astragalus	Alcohol precipitation	Rha: GalA: Gal: Ara: Glc: GlcA: Fuc=14.47: 49.55: 11.87: 21.47: 0.79: 1.16: 0.44	3373.20 kDa	1,2,3-β-Rhap, 1,4-β-GalpA, 1,2,6-β-Galp, 1,4-β-Galp, 1,2-α-GalpA, 1,2-β-Galp, 1,3,5-α-Araf, 1,4-β-GalpA, T-α-Araf, T-β-Rhap	Anti-inflammatory	(48)