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The study aims to clarify the structural domain required for the immune enhancement of ginseng neutral polysaccharide (GPN). GPN was first obtained through water extraction and ion-exchange chromatography from Panax ginseng. GPN was hydrolyzed by α-amylase for 24 h and fractionated through gel permeation chromatography to give two final fragments GPNE-I and GPNE-II, with molecular weight of 8.03 × 104 Da for GPNE-I and 3.15 × 104 Da for respectively. FT-IR, methylation and 1D/2D NMR analysis demonstrated that GPNE-I was a heteropolysaccharide consisting mainly of a glucan domain and type I and II arabinogalactans (AG-I and AG-II). GPNE II was a glucan consisting of (1 → 4)-α- d -Glcp backbone with a substitution at O-6 on every two residues. (1 → 3)-α- d -Glcp and (1 → 6)-α- d -Glcp were located at the branches. In the two fractions, both α- and β-t-Glcp as reductive terminals and →4)-α-Glcp as a non-reducing end were detected. The branching degrees of GPNE-I and GPNE-II were 38.17% and 50.78%, respectively. Immunological experiments revealed that GPNE-I exhibited more effectively stimulated lymphocyte proliferation than GPN and GPNE-II, indicating the former showed potential for immunomodulators applications, indicating that GPNE-I might be the core active domain and necessary for GPN to promote lymphocyte proliferation.

Two polysaccharides were obtained from steamed ginseng via ultrafiltration, and their physical–chemical properties, solution properties and antifatigue activities were studied. WSGP-S3 and WSGP-G3 were acid heteropolysaccharides with the molecular weights of 2.03 × 104 and 4.86 × 104, respectively. They were composed of different molar ratios of the monosaccharides Rha, GlcA, GalA, Glc, Gal, and Ara. The results of size-exclusion chromatography–multiangle laser light scattering analysis, Conge red staining and Circular dichroism spectroscopy revealed that WSGP-S3 exhibited a random conformation of branched clusters in solution. By contrast, WSGP-G3 exhibited an ordered conformation, including helix-like conformations in aqueous solution. Antifatigue activity tests proved that WSGP-S3 markedly prolonged the exhaustive swimming time of fatigued mice; increased liver and muscle glycogen levels and superoxide dismutase, catalase, glutathione peroxidase activities and decreased blood lactic acid, nitrogen and malondialdehyde levels compared with the control treatment. Moreover, it enhanced spleen cell proliferation in fatigued mice. By contrast, WSGP-G3 had no significant effect on fatigued mice. The results showed that WSGP-S3 might have a major contribution to the antifatigue effects of steamed ginseng polysaccharides and could be a potential anti-fatigue polysaccharide.

Two acid polysaccharides were obtained from steamed ginseng (GPS-1 and GPS-2) through water extraction, ion-exchange chromatography and gel chromatography. The structural features and ability of the polysaccharides to inhibit lipid accumulation in oleic acid-induced HepG2 cells were studied. GPS-1 consisted of type I arabinogalactans (AG-I), arabinogalactans-II (AG-II) and rhamnogalacturonan I (RG-I) domains. GPS-2 was a pectin-like polysaccharide consisting mainly of the homogalacturonan (HG) domain and a small amount of AG domain. Both GPS-1 and GPS-2 had branches attaching on O-3 of (1 → 6)-GalA or O-4 of (1 → 2)-Rha and terminated by either Ara or Gal. An in vitro experiment revealed that GPS-1 treatment at 50–400 μg/ml could dose-dependently decrease intracellular lipid accumulation and cholesterol (TC) and triglycerides (TG) levels. GPS-1 exerted a more serious hypolipidemic effect than GPS-2 did. Moreover, GPS-1 considerably increased the phosphorylation of AMP-activated protein kinase (AMPK) and affected the expression of AMPK downstream targets, including the inhibition of the protein expression of sterol regulatory element-binding protein 1c (SREBP-1c) and activation of Acetyl-CoA carboxylase (ACC). Results suggest that GPS-1 could inhibit lipid accumulation via the AMPK the signalling pathway.

In this study, we obtained and fractionated systematically the polysaccharides of Fructus mori fruit by the sequential use of water extraction, ethanol precipitation and ion-exchange chromatography. The sugar contents of FPA-1, FPA-2, FPA-4 and FPA-5 were estimated to be 75.70%, 67.15%, 87.78% and 91.63%, respectively. Monosaccharide composition analysis revealed that all the polysaccharides primarily contained Man, GlcA, GalA, Glc, Gal, Xyl, Ara and Fuc. Moreover, a small amount of Rha was detected in FPA-1, FPA-4 and FPA-5. The molecular weight distributions of FPA-1, FPA-2, FPA-4 and FPA-5 were 10.6–49.1 kDa, 22.9–122.7 kDa, 57.1–105.4 kDa and 14.8–19.6 kDa, respectively. According to the in vitro experiment, FPA-1 exhibited the highest activity on enhancing phagocytosis, promoting macrophage to secrete nitric oxide, tumour necrosis factor-α and reactive oxygen species.

An antioxidant-active polysaccharide (WMP) with a molecular weight of 26.91 kDa was isolated from Mentha haplocalyx Briq by water extraction, ethanol precipitation and gel filtration. According to HPLC, methylation, GC-MS, and 1D/2D nuclear magnetic resonance spectroscopy, WMP is a heteropolysaccharide composed of Gal (84.2 %), Glc (9.8 %), Man (2.8 %) and Ara (3.2 %) with (1→6)-α-d-Galp and (1→4, 6)-α-d-Galp residues in the backbone and (1→6)-α-d-Galp and (1→6)-α-d-Glcp residues in the branch. The branch point was located at C-4 of (1→4, 6)-α-d-Galp residue with a branching degree of 19.71 %. WMP showed remarkably high scavenging ability for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals, ferrous ion chelating activity and ferric reducing powder in vitro. In vivo result showed that WMP oral administration substantially increased the activities of antioxidant enzymes, including SOD, GSH-Px and CAT, and decreased MDA levels in the serum and liver of d-Gal-induced aging mice. Therefore, WMP can be an effective natural antioxidant.

Three acid polysaccharides obtained from Gynostemma pentaphyllum (Thunb.) Markino (named as GPA1, GPA2 and GPA3) using combination of water extraction, ion-exchange and gel permeation chromatography were subjected to composition analysis and valuated for the antioxidant activity. The sugar content of GPA1, GPA2 and GPA3 were 54.55%, 85.70% and 91.34%, respectively. Monosaccharide analysis showed that GPA1, GPA2 and GPA3 were all composed of Man, Rha, GlcA, GalA, Glc, Gal, Ara and Fuc, besides, GPA2 and GPA3 also contained Xyl. The molecular weight of GPA1, GPA2 and GPA3 were 19.6kDa, 10.6 kDa and 6.7 kDa, respectively. In vitro antioxidant assay, GPA1, GPA2 and GPA3 could scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical, chelate ferrous ion and reduce ferric ion. The antioxidant activities of GPA3 were stronger than those of GPA1 and GPA2, suggesting that GPA3 has significant potential as a natural antioxidant agent.

The structure and antioxidant activity of a neutral polysaccharide (named as EFPN-1) from Epimedium koreanum Nakai were studied. Based on the results from high performance gel permeation chromatography, methylation GC–MS and 1D/2D nuclear magnetic resonance spectroscopy, EFPN-1 was a branched polysaccharide with a molecular weight of 21.9 kD and containing over 60% of glucose. Its backbone was composed of (1 → 4)-β- d -Glcp and (1 → 3)-β- d -Galp, branched partially at O-6 of both residues, with a degree of branching of 40.4% and terminated mainly with Ara and Gal, as well as trace amount of Gal. Antioxidant tests showed that EFPN-1 exhibited a strong capacity on DPPH and hydroxyl radical scavenging, ferrous ion chelation and reducing antioxidant powder. EFPN-1 has potential to be developed as a natural antioxidant.

Phellinus pini exopolysaccharide (PPE) is a mannan produced by P. pini when cultured in potato dextroseagar medium. Partial hydrolysis with acid, periodate oxidation and Smith degradation, methylation and 13C nuclear magnetic resonance (NMR) spectroscopy were used to elaborate its structure. Results indicated that PPE contained a backbone of (1 → 2)-linked Man, which was heavily substituted via (1 → 6)-glucosidic bonds with (1 → 3)-linked Man, and terminated mainly with Man, as well as a small amount of Gal and Glc. Immunological tests showed that PPE exhibited high macrophages-activating ability, thereby augmenting phagocytosis and enhancing the production of nitric oxide, tumour necrosis factor-α and reactive oxygen species. Therefor, PPE had potential applications in developing functional food or in serving as a natural immnunostimulant.

Water-soluble ginseng oligosaccharides (designated as WGOS) with a degree of polymerization ranging from 2 to 10 were obtained from warm-water extract of Panax ginseng roots, and fractionated into five purified fractions (i.e., WGOS-0, WGOS-1, WGOS-2, WGOS-3, and WGOS-4) by gel-filtration chromatography. In order to ascertain the monosaccharide residues in the WGOS, a technique that combines acid hydrolysis and high-performance liquid chromatography was employed. It was found that only glucose residues were present in the WGOS. Fourier transform infrared spectroscopy and electrospray ionization tandem mass spectrometry provided the sequence, linkage, and configuration information. It is noteworthy that α-Glcp-(1 → 6)-α-Glcp, α-Glcp-(1 → 6)-α-Glcp-(1 → 4)-α-Glcp, α-Glcp-(1 → 6)-α-Glcp-(1 → 6)-α-Glcp-(1 → 4)-α-Glcp, and other six malto-oligosaccharides (i.e., maltopentaose, maltohexaose, maltoheptaose, maltooctaose, maltononaose, and maltodecaose) were detected in ginseng. Preliminary immunological tests in vitro indicated that WGOS were potent B and T-cell stimulators and WGOS-1 has the highest immunostimulating effect on lymphocyte proliferation among those purified fractions. It is hoped that the WGOS will be developed into functional food or medicine.

Two polysaccharides (WEA and WEB) were isolated from Enteromorpha intestinalis by hot water extraction, anion-exchange, and gel-permeation chromatography. The average molecular weights (Mw) of the two fractions were 72.03 kDa (WEA) and 60.12 kDa (WEB). WEA was composed of Rha, Xyl, Man, and Glc in a molar ratio of 1.39:1.00:0.13:3.23. WEB consisted of Rha, Xyl, Gal, and GlcA (glucuronic acid) in a molar ratio of 7.32:1.00:0.51:1.28. Both polysaccharides could inhibit tumor growth in S180 tumor-bearing mice, and increased the relative spleen and thymus weight. They also increased the expression of tumor necrosis factor-alpha (TNF-α) in serum. WEA and WEB induced lymphocyte proliferation, increased the production of TNF-α in macrophages, and stimulated macrophages to produce nitric oxide dose-dependently through the up-regulation of inducible NO synthase activity. However, no direct cytotoxicity against Sarcoma 180 was investigated in vitro. These results indicate that the antitumor effects of these polysaccharides are associated with immunostimulation.

The polysaccharide DAEB was isolated and purified from Enteromorpha intestinalis. It consisted of rhamnose, xylose, galactose, and glucose in a molar ratio of 5.36:1.00:0.57:0.64, and had a molecular weight of 46.8 kDa. Mice were treated with three doses of DAEB for 10 consecutive days by oral administration, the tumor inhibition was 61.17%, 67.65% and 70.59% at doses of 100, 200 and 400 mg/kg, respectively. However, no direct cytotoxicity was detected. At dose of 100, 200 and 400 mg/kg, a significant increase (P

Two water-soluble polysaccharides, PNW1 and PNM1, were respectively isolated from the mycelium and its culture medium of Phellinus nigricans using submerged fermentation before determining their effects on inhibiting the growth of transplantable tumors in mice. The results of the pharmaceutical experiments showed that oral administration of PNW1 and PNM1 (at a dose of 400 mg/kg) inhibited the growth of tumor of mice-transplanted Sarcoma 180 in vivo. Moreover, a higher inhibition ratio of PNW1 (74.70%) was obtained as compared with PNM1 (55.84%). The averaged molecular weight of PNW1 and PNM1 was determined to be 33 and 29 kD, respectively. Both PNW1 and PNM1 were consisted of glucose, galactose, mannose, arabinose and fucose. The major structural features of PNW1 and PNM1 were elucidated using partial acid hydrolysis, periodate oxidation, Smith degradation, 13C-NMR, methylation and GC-MS. On the basis of these results, the repeating units of PNW1 and PNM1 were established.

A new water-soluble intracellular polysaccharide named as PTP, with a molecular mass of 3.7x10(4) Da, was obtained from the mycelium of Polyporus albicans (Imaz.) Teng. Structure features of the purified polysaccharide were investigated by a combination of chemical and instrumental analysis. The results indicated that PTP consisted of a backbone composed of (1-->3)-linked-beta-d-mannopyranosyl, (1-->3,6)-linked-beta-d-mannopyranosyl and (1-->6)-linked-alpha-d-galactopyranosyl residues in the ratio of 3:1:1, and terminated with a single non-reducing terminal (1-->)-beta-d-mannopyranosyl residues at the C-6 position of (1-->3,6)-linked-beta-d-mannopyranosyl, along the main chain. This is the first report describing the isolation and structure elucidation of a new intracellular polysaccharide produced from the mycelium of P. albicans (Imaz.) Teng. Preliminary tests in vitro showed PTP have potent stimulating effects on murine lymphocyte proliferation induced by concanavalin A or lipopolysaccharide and its branches are extremely important for the expression of the enhancement of the immunological activity.