Optimum extraction of polysaccharides from motherwort leaf and its antioxidant and antimicrobial activities.

Box-Behnken design was employed to optimize the extraction conditions for polysaccharides from the leaves of motherwort (Leonurus cardiaca L.). Three independent variables including extraction temperature (60-100 °C), extraction time (60-120 min), and the ratio of water to raw material (20-60) were investigated. The results revealed that the quadratic and linear terms of three factors had strong effects on the extraction yield of polysaccharides from motherwort leaf. The best extraction conditions for the yield of polysaccharide (LCLP) was extraction temperature of 81.4 °C, time of 106.6 min and the ratio of water to raw material of 45.2. Under the optimal conditions, the extraction yield of LCLP was 9.17 ± 0.39%, which was well matched with value predicted by the model 9.26%. The results indicated that the purified LCLP exerted obvious scavenging effects on free radicals in vitro. Furthermore, motherwort polysaccharides could be used as a novel antimicrobial additive.

Tahmouzi S ，Ghodsi M 《-》

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 《-》

Optimization of polysaccharides from Zagros oak leaf using RSM: antioxidant and antimicrobial activities.

Ultrasonic assisted-extraction technique was applied to extract the polysaccharide from Zagros oak (Quercus brantii Lindl). The effects of four independent factors (ultrasonic power (X1: 150-300 W), extraction temperature (X2: 50-90°C), extraction time (X3: 30-90 min), and the ratio of water to raw material (X4: 15-45)) on the extraction yield of polysaccharide from the leaves of Q. brantii Lindl (QBLP) were optimized using response surface methodology. The experimental data obtained were fitted to a second-order polynomial equation. The optimal extraction conditions for QBLP were determined as follows: X1: 205.8 W, X2: 81.9°C, X3: 55.6 min and X4: 23.4. Under these optimal conditions, the experimental yield was 19.42 ± 0.53%, which was well matched with the value predicted by the model 19.61%. The results indicated that polysaccharide has strong scavenging activities in vitro on DPPH and hydroxyl radicals. In addition, the QBLP showed good antimicrobial activity at 1.5-2.5mg/mL.

Tahmouzi S 《-》

Optimization of extraction process and antioxidant activity of polysaccharides from leaves of Paris polyphylla.

Based on a single-factor test, a central composite design was used to optimize the extraction conditions of polysaccharides from leaves of Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. Three independent variables, including extraction temperature (°C), ratio of water to raw material, and extraction time (h), which significantly affected the yield of polysaccharides, were investigated. The experimental data were fitted to a quadratic polynomial equation using multiple regression analysis and also examined using appropriate statistical methods. The optimum conditions were as follows: extraction temperature, 90.8°C; ratio of water to raw material, 21.3:1; and extraction time 4.8h. Under these conditions, the experimental yield was 54.18%, which matched the predicted value well. Furthermore, the purified polysaccharide exerted strong antioxidant effects on DPPH, hydroxyl, and superoxide radicals in vitro.

Shen S ，Chen D ，Li X ，Li T ，Yuan M ，Zhou Y ，Ding C ... -  《-》

Optimization of enzyme-assisted extraction of polysaccharides from alfalfa and its antioxidant activity.

In this present study, an efficient complex enzyme-assisted extraction technology was developed and optimized to extract polysaccharides from alfalfa using four factors at five levels central composite rotatable response surface design (CCRD). The experimental data was fitted to a second order polynomial equation with high coefficient of determination values (R(2)>0.95). The results of statistical analysis showed that the linear and quadratic terms of these four variables had significant effects (P<0.05) on the yield of polysaccharides from alfalfa. The optimum conditions were as follows: enzyme concentration of 2.5%, 2.0%, 3.0% (weight of alfalfa) of cellulase, papain and pectase, extraction temperature 52.7 °C, extraction pH 3.87, ratio of water to raw material 78.92 mL/g and extraction time 2.73 h. Under the optimal conditions, the experimental extraction yield of alfalfa polysaccharides was 5.05 ± 0.02%, which was well matched with the value (5.09%) predicted by the CCRD model. Moreover, evaluation of the antioxidant activity of polysaccharides from alfalfa in vitro suggested that the polysaccharides had good antioxidant effect, especially scavenging activity for hydroxyl radical and DPPH radical, which indicated that the polysaccharides from alfalfa may be explored as a novel natural antioxidant.

Wang S ，Dong X ，Tong J 《-》