The optimization of sulfation modification conditions for ophiopogonpolysaccharide based on antiviral activity

► Nine sulfated ophiopogonpolysaccharides (sOPS1-sOPS9) were prepared. ► The effects of nine sOPSs on NDV to infect CEF were compared taking OPS as control. ► Sulfation modification could significantly enhance the antiviral activity of OPS. ► sOPS3 presented best effect and could be used as a component of antiviral drug. ► OPS's optimal modification conditions were CSA-Pry ratio at 1:4 reacting 2 h at 60 °C.