Chengcheng Zhao

The effect of different extraction techniques on property and bioactivity of polysaccharides from Dioscorea hemsleyi

The rhizoma of Dioscorea hemsleyi (DH) has been used as a treatment of diabetes in China for hundreds of years. Polysaccharides in DH were extracted by using ultrasonic-assisted extraction (UAE), cold water extraction (CWE), warm water extraction (WWE) and hot water extraction (HWE), separately. Then the different characterizations of four DH polysaccharide (DHP) samples were analyzed by high-performance liquid chromatography (HPLC), high-performance Gel permeation chromatography (HGPC), ultraviolet-visible spectroscopy(UV), fourier transform-infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Their activities in vitro of DHP were compared. Experimental results showed that HWE had the highest yield and large molecular weight. CWE had the highest uronic acid yield and little molecular weight, and its DPPH, AGI and AAI activity were the best. The molecular weight of UAE was small, and its RP and FRAP activity were the best. Four DHP samples had differences in the surface topography, while they all had the typical IR spectra characteristic of polysaccharides. According the correlation analysis, it showed that the more uronic acid and the lower molecular weight was, the higher the antioxidant activity was. The high content of monosaccharide composition of Xyl, Ara, GlcA and GalA, and little molecular weight have good effect on antidiabetic activity.

Physicochemical characterizations of polysaccharides from Angelica Sinensis Radix under different drying methods for various applications

Polysaccharides (ASP) were extracted from Angelica Sinensis Radix (ASR) and were subjected to freeze drying (ASP-FD), vacuum drying (ASP-VD), and hot air drying (ASP-HD). Structural characteristics, rheological and emulsifying properties, antioxidant, anticoagulant and alkaline phosphatase inhibitory activities of ASPs were firstly investigated. ASP-FD owned higher thermostability, unique morphological structure, uniform and the lowest molecular weight, which is suitable for using as a raw material for polysaccharide derivatives. Smaller viscosity of ASP-FD supplied a better appearance that consumers preferred and the smallest particle size was benefit to manufacture instant soluble products. ASP-VD behaved the highest neutral sugar content, protein content, intrinsic viscosities, and the best emulsifying activity, being a candidate for cosmetics additive. ASP-HD exhibited the highest apparent viscosities, higher thermostability, loose structure, and better bioactivities. Drying conditions had significant effect on the physicochemical properties and bioactivities of ASPs. ASPs with specific characteristics may meet the requirements for diverse applications.