Purification, characterization and in vitro anticoagulant activity of polysaccharides from Gentiana scabra Bunge roots

•Resin methods were employed to remove the proteins and pigments from polysaccharides of Gentiana scabra Bunge roots.•The weight-average molecular weights of purified polysaccharides (named GSP-2 and GSP-3) were analyzed by HPGPC.•Monosaccharide compositions of polysaccharide fractions were measured by HPAEC-PAD.•GSP-3 showed significant anticoagulant activity in APTT and TT assays. Three water-soluble polysaccharide fractions (GSP-1, GSP-2 and GSP-3) were obtained from Gentiana scabra Bunge roots by DEAE-Sepharose CL-6B and Sepharose CL-6B column chromatography. Their chemical characterizations were determined by high performance gel permeation chromatography (HPGPC), high performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) and Fourier transform infrared (FT-IR) spectrometer. Moreover, their in vitro anticoagulant activities were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) assays. GSP-1 and GSP-2 were composed of rhamnose, arabinose, galactose, glucose and galacturonic acid, while GSP-3 consisted of rhamnose, arabinose, galactose and galacturonic acid with a weight-average molecular weight of 5.8×104Da. In comparison with the control group (saline), GSP, GSP-1, GSP-2 and GSP-3 could prolong APTT and TT, but not PT. Overall, GSP-3 exhibited potent anticoagulant activity and would be expected to be a potential source of anticoagulant.