Optimization of microwave assisted extraction, chemical characterization and antitumor activities of polysaccharides from porphyra haitanensis.

Microwave assisted extraction (MAE) technology was used to extract polysaccharides from Porphyra Haitanensis (PHP) with water. Polysaccharide yield was used as index to evaluate the extraction process. Effects of ratio of water to raw material (X1), microwave power (X2) and extraction time (X3) on polysaccharide yield were investigated. Based on single factor experiment, MAE process of PHP was optimized using response surface methodology. Chemical characterization of PHP was investigated based on analysis of chemical compositions, monosaccharide and thermal gravimetric. The antitumor activities of PHP in vivo and in vitro were evaluated. The results indicated that the optimal conditions for MAE of PHP were ratio of water to raw material 28.98(mL/g), microwave power 77.84 W and extraction time 14.14 min. MAE was a suitable and efficient technique for PHP extraction compared with traditional hot water extraction. Analysis of chemical characterization showed that PHP contained 75.36 ± 1.48% of total carbohydrates, 24.63 ± 1.69% of uronic acid residue and no proteins with monosaccharides such as rhamnose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 10.25:9.38:1:12.45:9.9:11.55. Thermal gravimetric analysis suggested that PHP was relatively stable below 170℃. PHP had obvious effect on inhibiting proliferation, inducing apoptosis of SGC-7901 tumor cells in vitro and antitumor effect on SGC-7901 tumor-bearing mice in vivo. The results suggested that PHP had the potential for clinical use in cancer prevention and treatment.

Chen YY ，Xue YT 《-》

Ultrasonic/microwave-assisted extraction, simulated digestion, and fermentation in vitro by human intestinal flora of polysaccharides from Porphyra haitanensis.

In this study, we employed a response surface methodology to optimize the ultrasonic/microwave-assisted extraction (UMAE) conditions of Porphyra haitanensis polysaccharides (PHP), and subjected it to a stimulated in vitro digestion and fermentation model in order to investigate the digestion properties of PHP and the effects on human intestinal flora. The optimum extraction conditions consisted of an extraction time of 29.64 min, extraction temperature of 79.94 °C, and solid-liquid ratio of 1:41.79 g/mL. Under these conditions, the maximum yield of PHP predicted was 20.98%. The ζ-potential and thermal properties analysis verified that PHP was a negatively charged polymer, and possessed good thermal stability. Meanwhile, PHP was not digested in vitro by human saliva, simulated gastric and small intestinal juice. Furthermore, PHP modulated the microbiome structure, mainly increasing the relative abundance of Bacteroides and decreasing in the Escherichia_Shigella group. LEfSe analysis illustrated that Bacteroides, Lachnospiraceae_UCG_006 and Bacteroidales_S24_7_group could serve as potential biomarkers for the PHP supplement. This current study proved that the UMAE method was a highly efficient method to extract PHP to the maximum extent, and also provided insight concerning the stability performance of PHP and its prospects for application as a prebiotics candidate in the functional food industries.

Xu SY ，Chen XQ ，Liu Y ，Cheong KL ... -  《-》

Ultrasonic/microwave-assisted extraction of polysaccharides from Camptotheca acuminata fruits and its antitumor activity.

In the present study, an efficient ultrasonic/microwave-assisted extraction (UMAE) procedure for the polysaccharides from the fruit of Camptotheca acuminata (CAFP) was investigated and optimized. Under the optimum conditions (ratio of liquid to raw material 30 mL/g, microwave irradiation time of 20 min, microwave irradiation power of 570 W and a fixed ultrasonic power of 50 W obtained by the response surface analysis with Box-Behnken design, satisfactory yields of CAFP (6.81 ± 0.04%) were achieved. The development UMAE technique produced higher yields in a shorter time than conventional hot water extraction (HWE): 20 vs. 120 min. In addition, in vivo CAFP at suitable dose is effective on H22 murine hepatoma strains, and CAFP significantly inhibited the proliferation of human oral carcinoma KB, pancreatic carcinoma BXCP-3 and gastric carcinoma SGC-7901 cells in vitro, indicating CAFP might be suitable for nature antitumor therapeutic agent development.

Sun H ，Li C ，Ni Y ，Yao L ，Jiang H ，Ren X ，Fu Y ，Zhao C ... -  《-》

Structural characterization and antioxidant activity of polysaccharides extracted from Porphyra haitanensis by different methods.

This study was to investigate the structure and antioxidant activity of Porphyra haitanensis polysaccharides (PHPs) extracted by different methods, including water extraction (PHP), ultra-high pressure (UHP-PHP), ultrasonic (US-PHP) and microwave assisted water extraction (M-PHP). Compared with water extraction, the total sugar, sulfate and uronic acid contents of PHPs was enhanced by ultra-high pressure, ultrasonic and microwave assisted treatments, especially those of UHP-PHP were increased by 24.35 %, 12.84 % and 27.51 %, respectively (p < 0.05). Meanwhile, these assisted treatments affected the monosaccharide ratio of polysaccharides and significantly reduced the protein content, molecular weight as well as particle size of PHPs (p < 0.05), and resulted in a loose microstructure with more porosity and fragments. PHP, UHP-PHP, US-PHP, and M-PHP all possessed in vitro antioxidant capacity. Among them, UHP-PHP had the strongest oxygen radical absorbance capacity, DPPH and ·OH radicals scavenging capacities, which increased by 48.46 %, 116.24 %, and 14.98 % respectively. Moreover, PHPs particularly UHP-PHP effectively increased the cell viability and reduced ROS levels of H2O2 induced RAW264.7 cells (p < 0.05), indicating their good effects against cell oxidative damage. The findings suggested that PHPs with ultra-high pressure assisted treatments has the better potential to develop natural antioxidant.

Zheng M ，Ma M ，Yang Y ，Liu Z ，Liu S ，Hong T ，Ni H ，Jiang Z ... -  《-》

Optimization of ultrasonic/microwave assisted extraction (UMAE) of polysaccharides from Inonotus obliquus and evaluation of its anti-tumor activities.

Recently, the use of ultrasonic and microwave has attracted considerable interest as an alternative approach to the traditional extraction methods. In this paper, in order to maximize the yield and purity of polysaccharides from Inonotus obliquus, response surface methodology (RSM) was employed to optimize the ultrasonic/microwave assisted extraction (UMAE) conditions. The results indicated that the optimal conditions for UMAE were 90W microwave power, 50W ultrasonic power together with 40kHz ultrasonic frequency, solid/water ratio was 1:20 (W/V) and the extracting time was 19min, respectively. Under the optimal conditions, the yield and purity of polysaccharides were 3.25% and 73.16%, respectively, which are above that of traditional hot water extraction and close to the predicted value (3.07% and 72.54%, respectively). These results confirmed that ultrasonic/microwave assisted extraction (UMAE) of polysaccharides had great potential and efficiency compared with traditional hot water extraction. At the same time, the anti-tumor activities of the polysaccharides from I. obliquus with UMAE were evaluated. The results suggested that polysaccharides from I. obliquus exhibited obvious anti-tumor activities.

Chen Y ，Gu X ，Huang SQ ，Li J ，Wang X ，Tang J ... -  《-》