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 ... -  《-》

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 ... -  《-》

Optimization of extraction, characterization and antioxidant activity of polysaccharides from Brassica rapa L.

The root of Brassica rapa L. has been traditionally used as a Uyghur folk medicine to cure cough and asthma by Uyghur nationality in Xinjiang Uygur Autonomous Region of China. In the present study, therefore, extraction optimization, characterization and antioxidant activity in vitro of polysaccharides from the root of B. rapa L. (BRP) were investigated. The optimal extraction conditions with an extraction yield of 21.48 ± 0.41% for crude BRP were obtained as follows: extraction temperature 93°C, extraction time 4.3h and ratio of extraction solvent (water) to raw material 75 mL/g. The crude BRP was purified by chromatographic columns of DEAE-52 cellulose and Sephadex G-100, affording three purified fractions of BRP-1-1, BRP-2-1 and BRP-2-2 with average molecular weight of 1510, 1110 and 838 kDa, respectively. Monosaccharide composition analysis indicated that BRP-1-1 was composed of mannose, rhamnose, glucose, galactose and arabinose, BRP-2-1 was composed of rhamnose, galacturonic acid, galactose and arabinose, and BRP-2-2 was composed of rhamnose and galacturonic acid in a molar ratio of 1.27: 54.92. Furthermore, the crude BRP exhibited relatively higher antioxidant activity in vitro than purified fractions; hence, it could be used as a natural antioxidant in functional foods or medicines.

Wang W ，Wang X ，Ye H ，Hu B ，Zhou L ，Jabbar S ，Zeng X ，Shen W ... -  《-》

Characterization, antioxidant and antitumor activities of polysaccharides from Salvia miltiorrhiza Bunge.

Polysaccharides were extracted from Salvia miltiorrhiza Bunge using response surface methodology (RSM) with ultrasonication. A Box-Behnken design was used to optimize the extraction parameters to maximize the polysaccharide extraction yield. The polysaccharide SMP-U1 was isolated and characterized; then the antioxidant and antiproliferation activities were evaluated in vitro. The modified optimal conditions were an ultrasonic power of 180 W, an extraction temperature of 54°C, and an extraction time of 32 min, achieving an extraction yield of 40.54±0.25%. The results indicate that SMP-U1 has significant antioxidant activity, scavenging the free radical 2,2-diphenyl-1-picrylhydrazyl. It has also exhibited effect on the proliferation of human breast carcinoma cells Bcap-37 and human esophageal carcinoma cells Eca-109, especially at a concentration of 0.30 mg/mL. In conclusion, SMP-U1 has remarkable in vitro antioxidant and antiproliferation activity, and has potential for application as a natural antioxidant or antitumor agent.

Jiang YY ，Wang L ，Zhang L ，Wang T ，Yu L ，Ding CB ，Yang RW ，Wang XL ，Zhou YH ... -  《-》

Ultrasonic-assisted extraction and in-vitro antioxidant activity of polysaccharide from Hibiscus leaf.

The effects of ultrasonic power, extraction time, extraction temperature, and the water-to-raw material ratio on extraction yield of crude polysaccharide from the leaf of Hibiscus rosa-sinensis (HRLP) were optimized by statistical analysis using response surface methodology. The response surface methodology (RSM) was used to optimize HRLP extraction yield by implementing the Box-Behnken design (BBD). The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods (ANOVA). Analysis of the results showed that the linear and quadratic terms of these four variables had significant effects. The optimal conditions for the highest extraction yield of HRLP were: ultrasonic power, 93.59 W; extraction time, 25.71 min; extraction temperature, 93.18°C; and the water to raw material ratio, 24.3 mL/g. Under these conditions, the experimental yield was 9.66±0.18%, which is well in close agreement with the value predicted by the model 9.526%. The results demonstrated that HRLP had strong scavenging activities in vitro on DPPH and hydroxyl radicals.

Afshari K ，Samavati V ，Shahidi SA 《-》