Antioxidant and DNA damage protecting potentials of polysaccharide extracted from Phellinus baumii using a delignification method.

A delignification method was employed to extract the polysaccharide from the fruiting body of Phellinus baumii. The three parameters, processing temperature, ratio of water to raw material and amount of acetic acid every time were optimized using the Box-Behnken design. As a result, the optimal extraction conditions were: processing temperature 70.3°C, ratio of water to raw material of 34.7mL/g and amount of acetic acid of 0.32mL every time. Under these conditions, the highest yield of polysaccharide (10.28%) was obtained. The main fraction (PPB-2) purified from PPB was composed of fucose, arabinose, galactose, glucose, xylose and mannose, while glucose was the predominant monosaccharide. PPB-2 exhibited noticeable antioxidant activity and strong protection against oxidative DNA damage. These findings implied that acid-chlorite delignification was a superior method to extract the polysaccharide from P. baumii and PPB-2 may be useful for cancer chemoprevention.

Comparison of the preliminary characterizations and antioxidant properties of polysaccharides obtained from Phellinus baumii growth on different culture substrates.

Three polysaccharides (PPB-MB, PPB-MW and PPB-MM) were obtained from the fruiting body of Phellinus baumii growth on different culture substrates (mulberry branches, mixed wood sawdust and an equal combination of the two materials) and their chemical composition was investigated. PPB-MM contained the highest contents of neutral sugar (66.59%) and uronic acid (23.38%), followed by PPB-MW and PPB-MB, with PPB-MW having the highest protein content. The three polysaccharides were all composed of six kinds of monosaccharides, namely fucose, mannose, glactose, xylose, arabinose and glucose. The antioxidant activities of the three polysaccharides were determined using lipid peroxidant inhibition, ABTS radical scavenging, and Fe(2+)-chelating assay. Results showed that PPB-MM exhibited the highest antioxidant properties in all the assays. As a result, an equal combination of mulberry branches and mixed wood sawdust serves as a good culture substrate for producing such antioxidant polysaccharides.