BACKGROUND: Edible fungi polysaccharides usually exhibit antioxidant activity, and zinc has been shown to have antioxidant properties. In the present work, Pholiota nameko SW-03 was used as a vector of zinc biotransformation in order to obtain mycelia zinc polysaccharide (MZPS), and the structural characterization and anti-ageing activity of MZPS were investigated. RESULTS: Pholiota nameko SW-03 could accumulate zinc in the form of zinc-enriched polysaccharide, and the zinc content in MZPS was 16.39 ± 0.72 mg g(-1) . Three fractions (MZPS-1, MZPS-2 and MZPS-3) were successfully isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of glucose, mannose, glucuronic acid, galactose, galacturonic acid and arabinose in a molar ratio of 172.59:5.29:4.61:4.20:1.01:1.00, with a weight-average molecular weight of 13.63 kDa. The anti-ageing capability was measured in d-galactose-induced ageing mice, and the results showed that MZPS could improve antioxidant status (superoxide dismutase, total antioxidant capability, malondialdehyde and lipid peroxide), indicating that MZPS had strong anti-ageing capability in vivo. CONCLUSION: This study suggested that organification of zinc through edible fungi liquid fermentation provided a novel method to produce MZPS, which might be used as a natural antioxidant to slow the progression of ageing.
BACKGROUND: Edible fungi polysaccharides usually exhibit antioxidant activity, and zinc has been shown to have antioxidant properties. In the present work, Pholiota nameko SW-03 was used as a vector of zinc biotransformation in order to obtain mycelia zinc polysaccharide (MZPS), and the structural characterization and anti-ageing activity of MZPS were investigated. RESULTS:Pholiota nameko SW-03 could accumulate zinc in the form of zinc-enriched polysaccharide, and the zinc content in MZPS was 16.39 ± 0.72 mg g(-1) . Three fractions (MZPS-1, MZPS-2 and MZPS-3) were successfully isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of glucose, mannose, glucuronic acid, galactose, galacturonic acid and arabinose in a molar ratio of 172.59:5.29:4.61:4.20:1.01:1.00, with a weight-average molecular weight of 13.63 kDa. The anti-ageing capability was measured in d-galactose-induced ageing mice, and the results showed that MZPS could improve antioxidant status (superoxide dismutase, total antioxidant capability, malondialdehyde and lipid peroxide), indicating that MZPS had strong anti-ageing capability in vivo. CONCLUSION: This study suggested that organification of zinc through edible fungi liquid fermentation provided a novel method to produce MZPS, which might be used as a natural antioxidant to slow the progression of ageing.