Abstract:
Five fermented and purified exopolysaccharides (EPS Ⅰ~Ⅴ) from
Rigidoporus microporus,
Abortiporus biennis,
Funalia trogii,
Ginkgo polypores and Rigidoporus microporus(
Fr.)
Overh, were selected as the research objects. The antioxidant activity and reducing ability of the 5 EPS were tested by inhibiting free radicals to initiate DNA oxidation reaction and quenching the free radical reaction system. The results showed that all the five EPSs from polyporales have ability to inhibit the DNA oxidation reaction initiated by free radicals and capture free radicals. At the same time, there are regular differences in their antioxidant properties. In the six test systems, the antioxidant properties of the five EPSs are basically ranked as EPS Ⅳ> EPS Ⅴ> EPS Ⅱ> EPS Ⅰ> EPS Ⅲ. Among them, the EPS from
Ginkgo polypores (EPSⅣ) shows excellent antioxidant activity. The EPS Ⅳ, at a concentration of 40 mg/mL, can inhibit the DNA oxidation reaction system initiated by HO·, GS· and AAPH. The absorbance percentages of TBARS, compared to the blank sample, can reach 44.9%, 32.2% and 64.4%. The scavenging rates of ABTS+·, DPPH· and galvinoxyl· are as high as 52.7%, 63.2% and 83.9%. The antioxidant properties of EPS from
polyporales are highly correlated with its monosaccharide configuration.