Sulfated modification can enhance antiviral activities of Achyranthes bidentata polysaccharide against porcine reproductive and respiratory syndrome virus (PRRSV) in vitro.

Achyranthes bidentata polysaccharide (ABPS) was sulfated using the chlorosulfonic acid-pyridine method. The UV-spectrum of sulfated ABPS (sABPS) was characterized with two different absorbance peaks at 196.3 and 262.8 nm. FT-IR spectrum of sABPS exhibited absorption bands at 1236.5 cm(-1) (asymmetrical S=O stretching vibration) and 822.8 cm(-1) (symmetrical C-O-S vibration related to a C-O-SO(3) group). Anti-PRRSV activities of sABPS were tested on MARC-145 cells by MTT method. The results showed that sABPS exhibited significant antiviral activities at lower concentrations in comparison with the non-modified ABPS treated cells, indicating that sulfated modification could enhance antiviral activities of ABPS. These findings may provide the potential value to develop a new-type drug against PRRSV infection.