WEIQIANG HE¹, ZUOFA ZHANG²*

* Corresponding author

1. Institute of Biology and Environment, Jiaxing Vocational and Technical College,
Jiaxing 314036, China

2. Institute of Horticulture, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China

Abstract

Three polysaccharide fractions (FWP1, FWP2 and FWP3) with different molecular weights were obtained using ultra filtration membranes from crude polysaccharide extracted from the fruiting body of Flammulina velutipes (FWP). The chemical and physical characteristics of the three fractions were investigated by combination of chemical and instrumental analysis methods. Antioxidant activity was studied using in vitro models. FWP1 and FWP2 exhibited higher antioxidant activity than FWP3. Further work is under way to confirm the antioxidative effect of purified polysaccharide fractions and to characterize their structure-activity relationship.

INTRODUCTION

There is an increasing interest in the role of free radical-mediated damage in the aetiology of human diseases. Free radicals formed during oxidation process occurring in various products and biological systems are known to be responsible for oxidative deterioration, health damage and accelerated aging (1). It is well known to all that consumption of antioxidant-rich food will help to improve health status. However, many researchers reported the adverse effects of synthetic antioxidants such as toxicity and carcinogenicity (2). Due to safety and limitation of synthetic antioxidant usage, natural antioxidants obtained from edible materials have become alternately interesting (3).
Flammulina velutipes, one of the most popular edible mushrooms, has attracted considerable attention in the fields of biochemistry and pharmacology due to its biological activities (4, 5). It is reported that both the fruiting bodies and the fungal mycelia have bioactive polysaccharides of F. velutipes have been proved to be beneficial in immunomodulatory, anti-tumour, and biological activity on hepatocytes, antioxidant activity (6, 7).
For over three ...