Xiao-Cui Liu

Structural properties of polysaccharides from cultivated fruit bodies and mycelium of Cordyceps militaris.

The structural properties of polysaccharides, respectively, obtained from the fermented mycelium and cultivated fruiting bodies of the Cordyceps militaris were investigated and compared in this paper. First, the crude polysaccharides were extracted from the mycelium and the fruiting bodies, respectively. The polysaccharides were successively purified by Sevag and chromatography on Sephadex G-100 column to produce two polysaccharides fractions termed CMPS-II and CBPS-II, respectively. The average molecular weights of CMPS-II and CBPS-II were 1.402×10(3) kDa and 1.273×10(3) kDa, respectively, and they were mainly composed of mannose, glucose and galactose in the mole ratios of 1:28.63:1.41 and 1:12.41:0.74, respectively, for CMPS-II and CBPS-II. Afterward, the structural features of CMPS-II and CBPS-II were investigated by a combination of chemical and instrumental analysis, such as FT-IR, periodate oxidation-Smith degradation, GC-MS, NMR and methylation analysis. The results indicated that structurally, both CMPS-II and CBPS-II were 1,3-branched-galactomannoglucan that had a linear backbone of (1→4)-linked α-D-glucopyranose (Glcp). Congo-red test revealed that CMPS-II and CBPS-II existed as triple-helical chains in 0.05-0.15 M NaOH solution.

Effects of extraction methods on the yield, chemical structure and anti-tumor activity of polysaccharides from Cordyceps gunnii mycelia

This study was to investigate the effects of different extraction methods on the yield, chemical structure and antitumor activity of polysaccharides from Cordyceps gunnii (C. gunnii) mycelia. Five extraction methods were used to extract crude polysaccharides (CPS), which include room-temperature water extraction (RWE), hot-water extraction (HWE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and cellulase-assisted extraction (CAE). Then Sephadex G-100 was used for purification of CPS. As a result, the antitumor activities of CPS and PPS on S180 cells were evaluated. Five CPS and purified polysaccharides (PPS) were obtained. The yield of CPS by microwave-assisted extraction (CPSMAE) was the highest and its anti-tumor activity was the best and its macromolecular polysaccharide (3000-1000kDa) ratio was the largest. The PPS had the same monosaccharide composition, but their obvious difference was in the antitumor activity and the physicochemical characteristics, such as intrinsic viscosity, specific rotation, scanning electron microscopy and circular dichroism spectra.

Synthesis and antitumor activity evaluation of chrysin derivatives

A series of 5,7-disubstituted chrysin, 7-monosubstituted chrysin, 5-monosubstituted chrysin derivatives were synthesized by alkylation, acetylation, benzoylation, carboxymethylation, and evaluated on their antitumor activity of H22 cells in the search for potential antitumor agents. Among them, compound 3 (5,7-diacetyl chrysin) displayed the most potent antitumor activity with IC50 value of 141 μM. Moreover, there is significant up-regulation of G2 in cell cycle of H22.

Effect of ultrasonic treatment on structure and antitumor activity of mycelial polysaccharides from Cordyceps gunnii.

Taking mycelial polysaccharides from Cordyceps gunnii (C. gunnii) as the study subject, the effect of ultrasonic power, time and concentration of polysaccharides on antitumor activity of the polysaccharides was investigated. The ultrasonic processing condition of the polysaccharides was optimized by using orthogonal test design, and determined to be 400 W, 15 min and 1g/L. The change of structures of polysaccharides before and after ultrasonic treatment was also studied. Results show that ultrasonic treatment did not change the characteristic attribute of polysaccharides from C. gunnii. The composition of monosaccharide residues and the category of glycosidic bond have not been changed. But the molecular weight and intrinsic viscosity was reduced, and the alpha-helicity was enhanced after ultrasonic treatment. It was possible that ultrasonic treatment is an effective way for enhancing antitumor activity of polysaccharides.

Comparative evaluation of polysaccharides isolated from Astragalus, oyster mushroom, and yacon as inhibitors of α-glucosidase

The incidence of diabetes has increased considerably, and become the third serious chronic disease following cancer and cardiovascular diseases. Though acarbose, metformin, and 1-deoxynojirimycin have good efficacy for clinical application as hypoglycemic drugs, their expensive costs and some degree of side effects have limited their clinical application. Recently, increasing attention has concentrated on the polysaccharides from natural plant and animal sources for diabetes. In order to illustrate the pharmaceutical activity of polysaccharides as natural hypoglycemic agents, polysaccharides isolated from Astragalus, oyster mushroom, and Yacon were evaluated for their inhibitory effects on α-glucosidase. Polysaccharides were extracted and purified from Astragalus, Oyster mushroom, and Yacon with hot water at 90 °C for 3 h, respectively. The total sugar content of the polysaccharide was determined by the phenol-sulfuric acid method. The α-glucosidase inhibitory activity was measured by the glucose oxidase method. The results exhibited that the inhibitory effects on α-glucosidase were in decreasing order, Astragalus > oyster mushroom > Yacon. The α-glucosidase inhibition percentage of Astragalus polysaccharide and oyster mushroom polysaccharide were over 40% at the polysaccharide concentration of 0.4 mg·mL(-1). The IC50 of Astragalus polysaccharide and oyster mushroom polysaccharide were 0.28 and 0.424 mg·mL(-1), respectively. The information obtained from this work is beneficial for the use polysaccharides as a dietary supplement for health foods and therapeutics for diabetes.

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.

Efficient synthesis and activity of beneficial intestinal flora of two lactulose-derived oligosaccharides.

Lactulose is considered as a prebiotic because it promotes the intestinal proliferation of Lactobacillus acidophilus which is added to various milk products. Moreover, lactulose is used in pharmaceuticals as a gentle laxative and to treat hyperammonemia. This study was aimed at the total synthesis of two Lactulose-derived oligosaccharides: one is 3-O-β-d-galactopyranosyl-d-fructose, d-fructose and β-d-galactose bounded together with β-1,3-glycosidic bound, the other is 1-O-β-d-galactopyranosyl-d-fructose, d-fructose and β-d-galactose bounded together with β-1,1-glycosidic bound, which were accomplished in seven steps from d-fructose and β-d-galactose and every step of yield above 75%. This synthetic route provided a practical and effective synthetic strategy for galactooligosaccharides, starting from commercially available monosaccharides. Then we evaluated on their prebiotic properties in the search for potential agents of regulating and improving the intestinal flora of human. The result showed that the prebiotic properties of Lactulose-derived oligosaccharides was much better than Lactulose. Among them, 3-O-β-d-galactopyranosyl-d-fructose displayed the most potent activity of proliferation of L. acidophilus.

Synthesis and Antitumor Activity of a New Ergosterol Derivative

Ergosterol-3-O-(β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside) was efficiently synthesized and evaluated for its inhibitory activities against S180 cell lines compared with ergosterol. The structures of all synthesized compounds were fully characterized by spectroscopic data (NMR, MS). The antitumor activity of the new derivative was significantly enhanced compared with ergosterol.

Study on Submerged Fermentation Conditions for Intracellular Polysaccharide of Cordyceps gunnii

Optimization of liquid culture conditions on the production of intracellular polysaccharide by Cordyceps gunni was carried out in submerged cultures. According to single test and the orthogonal design, the results showed that the fermentation condition was sucrose 4 %, peptone 1.0 %, KH2PO4 0.05 %, MgSO4 0.15 %, shaking rate 150 r/min, initial pH natural, inoculation rate 8 %. The maximum intracellular polysaccharide production of 217 mg/100 mL was achieved with the optimized culture conditions.