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A novel acidic polysaccharide fraction (PZMP2-2) was isolated from Ziziphus Jujuba cv. Muzao fruit via hot water extraction and purified by DEAE-Sepharose FF and Sephacryl S-300 column chromatography. PZMP2-2 consisted of rhamnose, arabinose, xylose, galactose, and galacturonic acid in a ratio of 1.18: 5.23: 0.22: 2.68: 2.20, with a molecular weight of 62.73 kDa. Structural features of PZMP2-2 were investigated using FT-IR, SEM, AFM, GC–MS analysis and NMR spectroscopy. Methylation and GC–MS analysis revealed that the main glycosidic bonds in PZMP2-2 comprised 1-linked Galp, 1,3-linked Araf, 1,2,4-linked Rhap, 1,3-linked Galp, 1,4-linked GalpA and 1,3,5-linked Araf. NMR analysis indicate that PZMP 2–2 has a linear backbone of (1 → 4)-linked GlcpA and (1 → 2,4)-linked Rhap residues, with branches at the O-4 position, consisting of Araf and Galp residues.

A neutral polysaccharide (PZMP1) with a molecular weight of 16.97 kDa was isolated from Ziziphus Jujuba cv. Muzao with water extraction, ethanol precipitation, and purification with DEAE-Sepharose Fast Flow and Sephacryl S-300 column chromatography. PZMP1 was structurally characterized with high-performance gel-permeation chromatography, gas chromatography, Fourier transform infrared spectroscopy, methylation analysis, NMR spectroscopy, X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results show that PZMP1 is a homogeneous heteropolysaccharide composed of arabinose, galactose, glucose, mannose, and xylose in a molar percentage of 17.36: 3.29:2.68:1.05:1.00. The majorly backbone of PZMP1 is composed of 1,3,5-linked Araf, 1,3-linked Araf, 1,5-linked Araf, 1,4-linked Glcp, and 1-linked Araf, 1-linked Glcp. According to an NMR analysis, the repeating unit of PZMP1 is a linear backbone with branches at positions O-3, and O-5. PZMP1 also displays effective dose-dependent hypolipidemic activity, suggesting that it is a natural hypolipidemic agent, which could contribute to the functional food qualities of jujube fruit.

Stevia rebaudiana, a sweetener with medicinal functions, has attracted extensive attention due to its application in food and pharmaceutical fields. However, a few studies were performed to explore polysaccharides in this plant. Herein, SRP70-1 was derived from S. rebaudiana. Structural analysis (monosaccharide composition analysis, high-performance liquid chromatography-multi-angle light scattering detection, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy) revealed that SRP70-1 was composed of mannose, glucose, galactose, and arabinose at the molar ratio of 1.35:1.00:3.23:3.47, with an absolute molecular weight of 7698 Da. SRP70-1 was found to contain → 5)-α- l -Araf-(1→, →2,3,5)-α- l -Araf-(1→, →4)-β- l -Arap-(1→, →4)-β- d -Galp-(1→, →6)-β- d -Galp-(1→, →4)-β- d -Manp-(1→, →6)-β- d -Manp-(1→, and terminal α- l -Araf, β- d -Galp, and β- d -Glcp residues. Cell experiments showed that SRP70-1 could significantly promote phagocytosis and increase the release of nitric oxide and cytokines including IL-1β, IL-6, and TNF-α. Further zebrafish experiments confirmed the immunological enhancement effects of SRP70-1. This study revealed that SRP70-1 may be useful for the development of functional foods.

A water-soluble polysaccharide isolated from Cynomorium songaricum which is a traditional Chinese food was purified by Ultrahydrogel 500 gel filtration chromatography. The structural characterisation and hypoglycaemic activity of the purified polysaccharide fraction (CSPA) were evaluated. CSPA (Mw of 1.394 × 105 Da) was a heteropolysaccharide consisting of Ara, Glu and Gal. The conformation of CSPA was characterised as a compact chain of sphere-like structure in aqueous solution with a df value of 2.86. Linkage analysis and NMR (1D and 2D) revealed the presence of the following unit: → 3 ) - α - araf - ( 1 → 3 ) - α - d - glcp - ( 1 → 4 ) - α - d -Gal p A6Me- ( 1 → . Pharmaceutical experiments showed that the administration of CSPA could significantly decrease blood glucose levels, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, blood urea nitrogen, creatinine activities, and effectively increase serum insulin level and the content of liver glycogen in streptozotocin-induced diabetic rats. Histopathology studies showed that the reduced islet cells were restored to near normal upon treatment with CSPA. The results suggest CSPA could be considered as a potential candidate for developing a new anti-diabetic agent.

An intestinal immune system modulating polysaccharide (CUI-3IIb-3-2, 18kDa) was purified from Citrus unshiu peel. CUI-3IIb-3-2 mainly comprised GalA, GlcA, Ara, Gal and Rha, and it consisted of 4-linked GalA, terminal Araf, 4- or 5-linked/3,4- or 3,5-branched Ara, terminal Gal, and 2-linked/2,4-branched Rha. After CUI-3IIb-3-2 digestion by endo-α-d-(1→4)-polygalacturonase, its hydrolysate was fractionated into PG-1 and PG-2. Methylation analyses of PG-1 and PG-2 using base-catalysed β-elimination suggested that CUI-3IIb-3-2 be assumed as pectic-type polysaccharide. Since the activities of PG-1 and PG-2 were potently decreased, the whole polysaccharide structure of CUI-3IIb-3-2 would be essential to maintain the activity. Meanwhile, when CUI-3IIb was orally administered in mice, bone marrow cell proliferation and GM-CSF/IL-6 production from Peyer's patch cell were significantly higher (1.76- and 2.03/2.51-fold, respectively) than a saline. Therefore, a pectic-type polysaccharide from citrus peel could stimulate Peyer's patches and produce hematopoietic growth factors resulted in bone marrow cell proliferation.