Characterization and bioactivities of polysaccharide from spent Hovenia dulcis peduncles by alkali pretreatment

ABSTRACT

A novel heteropolysaccharide named SHDP was isolated from spent Hovenia dulcis peduncles (SHD) using alkali extraction. The preliminary characterization of the polysaccharide was performed by physicochemical and spectral methods. The bioactivities in vitro were also investigated. The results indicated that SHDPs are homogeneous with an average molecular weight of approximately 4570 kDa, and contain uronic acid (2.3%) and protein (3.6%). It is mainly composed of rhamnose, fucose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 3.04:1:8.55:8.51:3.80:19.85:9.59. The structure perhaps contains 6)-Glcp-(1→, 3)-Rhap-(1→, 4)-Xylp-(1→, 3)-Fucp-(1→. Meanwhile, xylose and arabinose were attached to (1→3, 6)-Manp and (1→3, 6)-Galp. Fourier-transform infrared (FTIR) analysis showed the typical polysaccharide absorption of the polysaccharide. Antioxidant activities assays in vitro indicated excellent 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2ʹ-azino-bis (3-ethylbenzthiazoline-6-suphonic acid) diammonium (ABTS) radical scavenging activities, high superoxide radical scavenging activity, and medium chelating ferrous ions activity in a dose-dependent manner. In addition, SHDPs have the ability to enhance the activity of alcohol dehydrogenase (ADH), which plays an important role in the process of preventing alcoholism.

KEYWORDS:

• Alkali extraction
• Bioactivities
• Polysaccharides
• Preliminary characterization
• Spent Hovenia dulcis peduncles

Acknowledgement

The authors would like to thank Mr Cheng Qian (University of Nevada, Reno, NV, USA) for his critical reading of the manuscript.

Funding

Financial support was received from National Natural Science Foundation of China (No. 41372245).

Additional information

Funding

Financial support was received from National Natural Science Foundation of China (No. 41372245).