Antioxidant activity of polysaccharide extracted from Ganoderma lucidum using response surface methodology.

Superfine grinding technology was applied for polysaccharide extraction from the fruiting bodies of Ganoderma lucidum, and response surface methodology (RSM) was used to optimize the effects of processing parameters on polysaccharide extraction yield. Results showed that the maximum yield of G. lucidum polysaccharides (GLP) was obtained at an optimum condition: extraction time 137 min, extraction temperature 66 ̊C, the ratio of water to material 35 mL/g, and the GLP extracting yield reached 2.44% under this condition. GLP were precipitated into three crude polysaccharides, viz. GLP40, GLP60 and GLP80. The basic characterization of polysaccharides was determined by using HPLC and FT-IR methods. GLP, GLP80, GLP60, and GLP40 were composed of Man, Rib, Glc, Gal and Fuc with the molar ratios of 1.27:0.36:22.89:1.61:0.33, 1.40:0.31:23.02:3.46:0.91, 0.96:0.34:25.76:2.47:0.46, and 2.81:1.42:23.83:1.61:0.33, respectively. The result of FT-IR suggested that the monosaccharide residue of the four polysaccharides was β-pyranoid ring. Moreover, the antioxidant activities of these four polysaccharides were evaluated. The results showed that GLP80 had the best reducing power, DPPH radical scavenging ability and oxygen radical scavenging ability followed by GLP, GLP60 and GLP40. Our results demonstrated that RSM might be a valuable technique for optimizing the efficient extraction of GLP, and G. lucidum could be considered as sources of natural antioxidants and preservatives of food industry. Moreover, polysaccharides, especially GLP80, extracted from the fruiting bodies of G. lucidum, exhibited promising antioxidant activities.

Kan Y ，Chen T ，Wu Y ，Wu J ，Wu J ... -  《-》

Antioxidant and immunoregulatory activity of Ganoderma lucidum polysaccharide (GLP).

Four polysaccharides (GLP-I, GLP-II, GLP-III and GLP-IV) were obtained from fermented soybean curd residue by Ganoderma lucidum, and then purified using anion-exchange DEAE Sephadex A-50. Their structural characterization was conducted by Fourier transform infrared spectroscopy (FTIR), and their monosaccharide compositions were determined. The results demonstrated that the basic structural characterization of four polysaccharides were similar, however, monosaccharide compositions of four kinds of polysaccharides were significant difference. GLP-III and GLP-IV were composed of six kinds of monosaccharide. Nevertheless, GLP-II was composed of three kinds of monosaccharide. Moreover, their antioxidant activities were investigated on the basis of hydroxyl radical, reducing power, DPPH free radical, chelating activity, ABTS radical-scavenging and SOD-like activity. The results showed that four polysaccharides exhibited antioxidant activities in a concentration-dependent manner. Among four polysaccharides, GLP-III and GLP-IV exhibited the higher scavenging effects on hydroxyl radicals, ABTS radical, DPPH free radical, and stronger reducing power and SOD-like activity than GLP-I and GLP-II. In addition, treatment with 40 μg/mL of GLP showed significant stimulation to the macrophage proliferation and higher nitric oxide production. Overall, GLP from fermented SCR could have potential applications in the medical and food industries.

Shi M ，Zhang Z ，Yang Y 《-》

Antioxidant activity of polysaccharide extracted from Pleurotus eryngii using response surface methodology.

Ultrasonic technology was applied for polysaccharide extraction from the fruiting bodies of P. Eryngii, and response surface methodology (RSM) was used to optimize the effects of processing parameters on polysaccharide extraction yield. Three independent variables were extraction time (A), ultrasonic power (B) and the ratio of solvent to sample (C), respectively. Results showed that the maximum yield of P. eryngii polysaccharide (PEPS) was obtained at an optimum condition: extraction time 39 min, ultrasonic power 517 W, the ratio of water to material 19 mL/g, and the PEPS extracting yield reached 34.3% under the conditions. PEPS were precipitated into three crude polysaccharides, PEPS30, PEPS60 and PEPS80, by different concentrations of ethanol respectively. The antioxidant activities of these three polysaccharides were evaluated. The results showed that PEPS80 had the best reducing power, DPPH radical scavenging ability and oxygen radical scavenging ability followed by PEPS60 and PEPS30.

Zhang A ，Li X ，Xing C ，Yang J ，Sun P ... -  《-》

Characterization and antioxidant activity of two low-molecular-weight polysaccharides purified from the fruiting bodies of Ganoderma lucidum.

Two low-molecular-weight polysaccharides, GLP(L)1 and GLP(L)2, purified from a crude Ganoderma lucidum polysaccharide preparation GLPP were investigated for their physicochemical properties, structure characterization and antioxidant activities. The results indicated that GLP(L)1 was a glucan with an average molecular weight of 5.2kDa, while GLP(L)2 was composed of glucose, galactose and mannose in a ratio of 29:1.8:1.0 with the average molecular weight of 15.4kDa. GLP(L)1 and GLP(L)2 had similar structure characteristic which contained linkages such as -->3)-Glcp-(1-->, -->4)-Glcp-(1-->, -->6)-Glcp-(1-->, -->3,6)-Glcp-(1-->, and -->4,6)-Glcp-(1--> in the percentage ratio of 21.9:20.3:23.7:24.0:3.7 and 23.0:34.6:7.0:14.1:3.0 in the backbone or branches, respectively. Antioxidant results showed that both GLP(L)1 and GLP(L)2 exhibited antioxidant activities while GLP(L)1 was more effective in free radicals scavenging and Fe(2+) chelating. Low-molecular-weight polysaccharide seems to play an important role in the exploration of natural antioxidants in food industry and pharmaceuticals.

Liu W ，Wang H ，Pang X ，Yao W ，Gao X ... -  《-》

Antioxidant activity and optimization of extraction of polysaccharide from the roots of Dipsacus asperoides.

Polysaccharide extraction from Dipsacus asperoides roots (DAP) was proved to possess strong antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-Azobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities, inhibiting β-carotene bleaching and strong reducing power. Cell assay demonstrated that the crude DAP possessed antioxidant activity and were effective against H2O2-induced L02 cells injury. Then, response surface methodology (RSM) was applied to optimize the ultrasonic extraction of DAP. The optimum variables given by central composite design (CCD) were as follows: ratio of water to raw material, 38.61mL/g; ultrasonic power, 308.68W; extraction time, 38.61min; and extraction temperature, 89°C. Under these conditions, the maximum yield of DAP obtained was 7.12±0.45%. Moreover, high performance liquid chromatography (HPLC) analysis suggested that the monosaccharide compositions of DAP contained primarily mannose, ribose, glucose, galactose, xylose and arabinose, with a molar ratio of 0.22:0.48:2.29:0.34:1.39:1.41. The results of the present study showed that DAP could be considered as potential sources of natural antioxidants.

Tan LH ，Zhang D ，Yu B ，Zhao SP ，Wang JW ，Yao L ，Cao WG ... -  《-》