Effect of extraction methods on the properties and antioxidant activities of Chuanminshen violaceum polysaccharides.

The yields, properties and antioxidant activities of polysaccharides extracted from Chuanminshen violaceum (CVPs) by various methods including heated reflux extraction (HRE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), were evaluated. The results indicated that the yield of the polysaccharides (34.59%) obtained by MAE was higher than those obtained by other methods. Polysaccharides extracted by all three methods had similar physicochemical characteristics and FT-IR spectra. However, SEM images of particles of Chuanminshen violaceum treated by the three different methods were significantly different. Compared with HRE, UAE and MAE resulted in CVPs with lower molecular weight distributions and higher reducing power and scavenging abilities for ABTS + and DPPH. CVPs obtained by UAE had reduced scavenging abilities for DPPH compared to those obtained by MAE. These data indicated that MAE resulted in better extraction yields for CVPs and also resulted in CVPs with higher bioactivity.

Dong H ，Lin S ，Zhang Q ，Chen H ，Lan W ，Li H ，He J ，Qin W ... -  《-》

Extraction, characterization and antioxidant activities of polysaccharides of Chuanminshen violaceum.

A single factor experiment and Box-Behnken design were applied to optimize the microwave-assisted extraction (MAE) of Chuanminshen violaceum polysaccharides (CVPs). The CVPs yield was 34.59 ± 0.51%, which was in accordance with the predicted value of 35.54%, under the following optimum conditions: microwave power of 466 W, extraction temperature of 64.5 °C, extraction time of 15 min, and water-raw material ratio of 40 mL/g. Two CVPs fractions (CVPs-I and CVPs-II) were obtained via stepwise ethanol precipitation. CVPs-II was further purified using DEAE cellulose-52 chromatography to obtain the major fraction of CVPs-IIa. Fourier transform infrared spectroscopy (FTIR) and GC-MS analysis revealed that crude CVPs, CVPs-I, and CVPs-II were neutral polysaccharides and were mainly composed of glucose and galactose. The molecular weights of CVPs-I and CVPs-IIa were 233.69 and 11.02 kDa, respectively. Furthermore, all samples exhibited certain antioxidant activity or reducing power to scavenge the DPPH and ABTS radicals, among which CVPs-II was the strongest. In conclusion, MAE is an efficient method for extracting CVPs of C. violaceum, and this plant root has the potential to be explored as a source of natural antioxidants.

Dong H ，Zhang Q ，Li Y ，Li L ，Lan W ，He J ，Li H ，Xiong Y ，Qin W ... -  《-》

Structural characterization, antioxidant activity, and immunomodulatory activity of non-starch polysaccharides from Chuanminshen violaceum collected from different regions.

Chuanminshen violaceum has been used as an important traditional Chinese medicine and a popular tonic food in China. Polysaccharides are considered the major bioactive components in C. violaceum. In this study, in order well understand the chemical structures and bioactivities of non-starch polysaccharides in C. violaceum (CVPs), the physicochemical structures, antioxidant activities, and immunomodulatory activities of CVPs in C. violaceum collected from different regions of China were investigated and compared. Results showed that the constituent monosaccharides and Fourier transform infrared spectra of CVPs in C. violaceum collected from different regions were similar. However, their molar ratios of constituent monosaccharides, molecular weights, and contents of uronic acids were different. Furthermore, CVPs exerted remarkable antioxidant activities (ABTS and nitric oxide radical scavenging capacities) and immunomodulatory activities (promoted production of nitric oxide, IL-6, and TNF-α from RAW 264.7 macrophages in vitro). Meanwhile, the antioxidant and immunomodulatory activities of CVPs extracted from C. violaceum also varied by cultivated regions. Moreover, results indicated that the antioxidant and immunomodulatory activities of CVPs were closely correlated to their α-1,4-d-galactosiduronic linkages. Results are helpful for better understanding of the structure-bioactivity relationships of CVPs, and beneficial for the improvement of their applications in pharmaceutical and functional food industries.

Lin S ，Li HY ，Yuan Q ，Nie XR ，Zhou J ，Wei SY ，Du G ，Zhao L ，Wang SP ，Zhang Q ，Chen H ，Qin W ，Wu DT ... -  《-》

Physicochemical properties and antioxidant activities of polysaccharides sequentially extracted from peony seed dreg.

The sequential extraction of peony seed dreg polysaccharides (PSDP) with hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS) and concentrated alkaline (CASS) yielded four different polysaccharide fractions. Based on their absorptions at 3600-3200cm(-1) and 1200-800cm(-1), these fractions were confirmed to be polysaccharides. The properties of four PSDPs displayed some slight differences. The CASS showed the highest peak temperature and endothermic enthalpy. The emulsifying activity and emulsifying stability of four PSDPs exhibited a dose-dependent pattern; HBSS showed the highest emulsifying activity, and CHSS displayed the longest emulsifying stability. The four PSDPs also exhibited wide variations in their antioxidant activities. For example, i) CASS showed the highest DPPH radical scavenging activity, reducing power and ABTS radical scavenging activity; ii) HBSS exhibited the highest hydroxyl radical scavenging activity, and iii) CHSS displayed the higher ferrous ions chelating ability than others.

Shi JJ ，Zhang JG ，Sun YH ，Qu J ，Li L ，Prasad C ，Wei ZJ ... -  《-》

Physicochemical properties and activities of comfrey polysaccharides extracted by different techniques.

The effects of extraction techniques on the physicochemical properties, antioxidant activity and antihyperglycemic activity of comfrey polysaccharides (CPs) were evaluated. Four techniques were used to extract CPs: hot water extraction (HW), ultrasonic-assisted extraction (UA), enzyme-assisted extraction (EA) and enzyme-ultrasonic-assisted extraction (EUA). Experimental results indicated that CPs extracted by the UA (UA-CPs) and EUA methods (EUA-CPs) had higher extraction yields. The four CPs showed the same monosaccharide composition but a significant difference in monosaccharide content. CPs showed antioxidant activities and antihyperglycemic activities in a concentration-dependent manner. UA-CPs exhibited better antioxidant capacity, which might have been related to its smaller molecular weight and higher uronic acid content. In addition, UA-CPs showed notable α-glucosidase inhibition activity. These results suggested that ultrasonic-assisted extraction technology was more beneficial to enhance the extraction yields of the polysaccharides, and obtain higher bioactive polysaccharides from comfrey.

Duan M ，Shang H ，Chen S ，Li R ，Wu H ... -  《-》