A new acidic polysaccharide and its sulfated derivative from cultured Morchella sextelata fruiting bodies and their antioxidant and immunoregulatory activities

A new polysaccharide (MSPW70-1) was isolated from Morchella sextelata.Structural analysis indicated that MSPW70-1was characterized as a repeating unit consisting of -> 2)-alpha-d-Galp-(1 -> , -> 3,6)-alpha-d-Manp-(1 -> and -> 2,3,6)-alpha-d-Manp-(1 -> , -> 4)-beta-d-Glcp-(1 -> , -> 4)-alpha-d-GlcpNAc-(1 -> , -> 6)-alpha-d-Manp-(1 -> , t-alpha-d-Galp, t-beta-d-Glcp, and t-alpha-d-GlcpNAc. This is the first polysaccharide containing N-acetylglucosamine isolated from M. sextelata.Furthermore, three sulfated derivatives of MSPW70-1 (MSPW70-M1, MSPW70-M2, and MSPW70-M3) were also synthesized. Antioxidant assays revealed that the sulfated derivatives with a proper DS value could enhance the scavenging activities of MSPW70-1 against DPPH center dot and ABTS(+)center dot radicals with IC50 values of 871.68 and 622.18 mu g/mL, which was 1.22 and 1.35 times higher than that of MSPW70-1. Moreover, immunoregulatory assays in vitro showed that MSPW70-M1 could markedly promote the proliferation of mouse spleen lymphocyte with proliferation rate value of 681.35%, which was 1.36 times higher than that of MSPW70-1. All of the activity evaluations indicated that the sulfated derivatives with an appropriate DS value could improve the activity of M. sextelata polysaccharide.

Automated summary

A new polysaccharide was isolated from Morchella sextelata, and three sulfated derivatives were synthesized. The sulfated derivatives with an appropriate DS value showed enhanced antioxidant and immunoregulatory activities.