Huiqing Sun

Synthesis, characterization and antioxidant activity of selenium polysaccharide from Cordyceps militaris.

A purified selenium-containing derivatives of Cordyceps militaris polysaccharide synthesized using H2SeO3/HNO3 and BaCl2 as a catalyst was investigated in this paper. The reaction condition was optimized by selecting different reaction temperature and period. Afterward, the one with the highest Se content was purified by ultra-filtration device with a molecular cut off size of 10KDa. Followed by its structural characterizations. Results of IFR and 13C NMR spectroscopy indicated that C-6 substitution was predominant in selenized polysaccharide. The modified polysaccharide with molecular weight of 1998 KDa was mainly consisted of mannose, glucose and galactose in the mole ratios of with the mole ratios of 1:28.63:1.41. Thermogravimetric and morphological analyses of the samples were carried out by AFS, SEM and AFM. In addition, the in vitro antioxidant results suggested that selenium-containing polysaccharide should be applied as a novel selenium source in dietary supplements, with potent antioxidant properties.

Structural characterization and inhibition on α-d-glucosidase activity of non-starch polysaccharides from Fagopyrum tartaricum

In the present study, the crude polysaccharide was extracted from Fagopyrum tartaricum and purified by Sephadex G-25 and G-75 column to produce a polysaccharide fraction termed TBP-II. Its average molecular weight was 26kDa. The structural characterization of TBP-II was investigated by gas chromatography, periodate oxidation-Smith degradation, Methylation and NMR. Congo red was applied to explore its advanced structures. The results revealed that chemical composition and structural characteristic of TBP-II was mainly consisted of galactose, arabinose, xylose and glucose with a molar ratio of 0.7:1:6.3:74.2. The backbone of TBP-II was composed of (1→4)-linked α-d-glucopyranosyl (Glcp), while the branches comprised of (1→3)-linked α-d-glucopyranosyl (Glcp), (1→6)-linked α-d-galactopyranosyl (Galp) and (1→2,4)-linked α-d-rhamnopyranosyl (Rhap). The structure of TBP-II was 1,3 and 1,6-branched-galactorhamnoglucan that had a linear backbone of (1→4)-linked α-d-glucopyranose (Glcp). Using Congo red assay showed that it was absent of triple helix structure. The α-d-glucosidase inhibitory activity of TBP-II was determined using acarbose as positive control. The result showed that the inhibition rate depended on the concentration of polysaccharides.

Structural characterization and anti-tumor activity of polysaccharide produced by Hirsutella sinensis

HSP-III, a novel homogeneous polysaccharide with 513.89 kDa molecular weight, was fractionated from submerged cultures of Hirsutella sinensis by Sevag and chromatography on Sephadex G-100 column. The total sugar content of HSP-III was amounted to 89.87%. Based on the results of high performance gel permeation chromatogram (HPGPC), FT-IR, NMR spectroscopy, GC, periodate oxidation-smith degradation and methylation analysis, it showed that HSP-III was mainly composed of mannose and galactose, and a small amount of rhamnose, arabinose, xylose, and glucose. The molar ratio of Rha:Ara:Xyl:Man:Glu:Gal was 1.00:2.44:13.11:74.13:13.80:54.39. The main chain of HSP-III was majorly composed of (1→3) glucose. The tumor inhibition ratio on H22 cell was 79.04% at 100 μg/mL of HSP-III.

Anti-tumor effect of polysaccharide from Hirsutella sinensis on human non-small cell lung cancer and nude mice through intrinsic mitochondrial pathway

Our previous works had proved the structural properties of Hirsutella sinensis polysaccharide-III(HSP-III). Herein, its anti-tumor effect on lung cancer correlated with mitochondrial apoptosis pathway was investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that HSP-III induces the apoptosis of H1299 cells; however the proliferation viability of normal lung epithelial cells is not affected. HSP-III treatment collapses the H1299 cell mitochondrial membrane potential, and western blot analysis of cytochrome C, Bax, caspase-3 and caspase-9 further indicates that apoptotic effects induced by HSP-III is through the mitochondrial pathway. Furthermore, we found the apoptotic effects of HSP-III are triggered by Reactive oxygen species (ROS) generation. Blue native Polyacrylamide Gel-Electrophoresis (PAGE) showed the expressions of mitochondrial respiratory chain complexes I-V were also decreased. Taken together, anti-tumor effect of HSP-III is through intrinsic mitochondrial apoptosis mechanism pathway and involving ROS increasing. Finally, in vivo nude mice experiment, HSP-III attenuated the growth of tumor compared with control. In contrast, N-acetyl-l-cysteine (NAC) could restore the cell apoptosis effects induced by HSP-III. These findings suggest that HSP-III induce apoptosis of H1299 cells and attenuated growth of nude mice tumor in vivo through the intrinsic mitochondrial pathway and stimulating ROS. HSP-III could be a composition for lung cancer treatment.

Structural characterization and inhibition on α-glucosidase activity of acidic polysaccharide from Annona squamosa

The crude polysaccharide (TASP3) was extracted from the fruit pulp of Annona squamosa and then isolated and purified by the combination of grading-alcoholic precipitation and Sephadex G-200. The structure of purified polysaccharide (GASP3-3-I) was determined based on the physicochemical and instrumental analyses. The results indicated that GASP3-3-I was an acidic heteropolysaccharide and its average molecular weight was 2.28×106Da. The monosaccharide composition was analysed by GC-MS and ion chromatography, respectively. It was revealed that GASP3-3-I was consisted of rhamnose, arabinose, xylose, mannose, glucose, galactose, glucuronic acid and galacturonic acid with a molar ratio of 5.06:45.5:5.26:0.63:6.09:31.76:0.49:5.19. Moreover, periodate oxidation reaction, Smith degrading reaction, methylation, FT-IR and NMR were used to conduct the structural characterization of GASP3-3-I. The results indicated that glycosyl residues of GASP3-3-I were mainly composed of (1→) l-arabinose, (1→6), (1→3) and (1,3→6) d-galactose, (1→) d-xylose, (3→) and (3→6) d-glucose, (1→2) l-rhamnose. The α-glucosidase inhibitory activity assay showed that GASP3-3-I had a certain inhibition on α-glucosidase activity.

Preliminary characterization and immunostimulatory activity of a novel functional polysaccharide from Astragalus residue fermented by Paecilomyces sinensis

An Astragalus residue was reutilized through solid-state fermentation by Paecilomyces sinensis, which is a member of Ophiocordyceps sinensis (Berk.) Sacc. In this research, the polysaccharide from the product of solid-state fermentation primarily was studied. First, HPLC, FT-IR, and GC were applied to study the preliminary characterization of a polysaccharide (APP-II) from the solid-state fermentation product Astragalus residue and Paecilomyces sinensis. Results indicated that APP-II is a-pyran polysaccharide with an average molecular weight of 670 kD that is composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose with a molar ratio of 4.0 : 4.2 : 2.0 : 41.4 : 22.5 : 25.9. Second, an immunostimulatory activity of APP-I and APP-II was detected. Results suggested that APP-I and APP-II could promote RAW264.7 cell proliferation. APP-I was used to detect the immunostimulatory activity of APP-II in vivo. The results indicated that APP-I can promote growth of immune organs, stimulate splenocyte proliferation, and enhance NK activity; this indicated that APP-II had immunostimulatory activity in vivo. All the results indicated that APP-II is a novel polysaccharide with immunostimulatory activity.

Structural properties and antioxidant activities of polysaccharide from fruit bodies of Pholiota nameko

Abstract A polysaccharide named PNP was extracted and purified from Pholiota nameko. The total sugar content of PNP was 95.29% and the molecular weight was 1.89 × 103 kDa. The structural features of PNP were investigated by the combination of chemical and instrumental analysis such as UV spectrophotometer, specific rotation determination, FT-IR, methylisation analysis and Congo red. The results showed that the optical rotation of PNP was +120° and that it had a triple-helical structure. Besides, PNP was mainly composed of glucose and mannose at the molar ratio of 4.24:1.00. The backbone of PNP was composed of (1→3)-linked-Glc and (1→3)-linked-Man whereas the branches of (1→3,6)-linked- Glc, (1→3,6)-linked-Man and T- Glc. Consistenting with the results of UV–Vis spectra, FT-IR spectroscopy and 1H NMR, indicated that PNP was a complex of polysaccharides and polyphenols. In vitro antioxidant results suggested that PNP was processed with certain scavenging capacity.

Structural characterisation and ACE-inhibitory activities of polysaccharide from Gastrodia elata Blume.

Abstract The structural properties and Angiotensin-I converting enzyme (ACE) inhibition activities of a polysaccharide (PGE) extracted from Gastrodia elata Blume were investigated. PGE was extracted using hot water and purified by Sephadex G-200 followed by ultra-filtration. The structural characterisation of PGE was analysed by FT–IR, NMR spectroscopy, specific rotation determination, periodate oxidation-smith degradation, methylation analysis, GC–MS and Congo red test. The results revealed that PGE was composed by glucose, with an average molecular weight of 1.54 × 103 kDa. The structure of PGE was 1→3 and 1→4,6-branched-glucopyranose that had a linear backbone of (1 → 4)-linked-d-glucopyranose (Glcp). ACE-inhibitory activity results showed that PGE was efficient to inhibit ACE and the IC50 value was 0.66 mg/mL.

Structure analysis and anti-fatigue activity of a polysaccharide from Lepidium meyenii Walp

Abstract A polysaccharide was obtained from Lepidium meyenii Walp by hot water extraction and purification by Millipore (100 kD) and Sephadex G-200. The content of polysaccharide was examined to be 89.9% with phenol-sulfuric acid method. Its average molecular weight was estimated to be 2.213 × 106 Da by High Performance Gel Permeation Chromatography (HPGPC). Monosaccharide analysis showed that the polysaccharide was composed of arabinose, mannose, glucose and galactose with the molar ratio of 2.134: 1: 2.78: 2.82. After Smith degradation, methylation, infrared spectroscopy and NMR, the primary structure of the polysaccharide was identified. The backbone of the polysaccharide was composed of →4)-β-D-Galp-(1→ and →4)-α-D-Galp-(1→, while the branches were comprised of →6)-β-D-Glup-(1→, →5)- β-D-Araf-(1→, →3,6)-α-D-Manp-(1→, →3)-α-D-Galp-(1→, and α-D-Glup-(1→. The anti-fatigue effect of the polysaccharide was evaluated using exhaustive swimming test and biochemical indexes. The results indicated the polysaccharide has anti-fatigue effect.

The chemical structure and anti-aging bioactivity of an acid polysaccharide obtained from rose buds

An acid polysaccharide, named R-PL, was extracted from rose buds by hot water (80 °C) extraction and purified by Sephadex G-200. R-PL, extracted with a total yield of 1.90%, is a highly pure polysaccharide with a total sugar content of 92.51%. A single and symmetrically sharp peak in its high-performance gel-permeation chromatography (HPGPC) spectrum indicates that R-PL is a homogeneous polysaccharide with a molecular weight of 7.727 × 105 Da. Monosaccharide composition analysis shows that it consists of d-arabinose, d-xylose, d-glucose, d-galactose, d-galacturonic acid, and d-glucuronic acid with a molar ratio of 4.6 : 1.4 : 5.22 : 4.81 : 1 : 1.86. Structure analysis, such as FTIR spectroscopy, periodic acid oxidation, Smith degradation, methylation, and NMR analysis, reveals that R-PL has a backbone of →1)-α-d-Glcp-(6→ with side chains of →1)-β-d-Galp-(4,6→, →1)-β-d-Araf-(5→, →1)-α-d-Xylp-(4→, →1)-α-d-GlcpA-(2→ and →1)-α-d-GalpA-(4→. Its morphological characteristics were identified by Congo red experiments and scanning electron microscopy (SEM) analysis. The results show that R-PL does not have a triple-helical conformation in solution; its shape resembles twisted ribbons. Anti-oxidative and anti-aging analyses show that R-PL has significant antioxidant and anti-aging abilities in vivo.