Preparation, structure and anticoagulant activity of a low molecular weight fraction produced by mild acid hydrolysis of sulfated rhamnan from Monostroma latissimum

► LMWP was prepared by mild acid hydrolysis of the sulfated rhamnan. ► LMWP is a sulfated rhamnan with specific rhamnopyranose units. ► LMWP possessed a good anticoagulant activity in vitro. ► LMWP is a thrombin inhibitor mediated by heparin cofactor II. ► LMWP was a potential source of anticoagulant polysaccharide.