Structural characterization and antiviral effect of a novel polysaccharide PSP-2B from Prunellae Spica

Abstract

In the present study, a novel polysaccharide, PSP-2B, was isolated from aqueous extracts of Prunellae Spica by direct ultrafiltration membrane separation and gel chromatography purification. PSP-2B is a partially sulphated polysaccharide with a molecular weight of approximately 32kDa. Its sulfate content is 10.59% by elemental analysis. The major sugars comprising PSP-2B are arabinose, galactose and mannose, in addition to small amounts of glucose and uronic acids. The framework of PSP-2B is speculated to be a branched arabinogalactomannan, and the side chains are terminated primarily by the Araf residues. PSP-2B also contains 2.98% protein. PSP-2B exhibits activity against herpes simplex virus (HSV), with a half maximal inhibitory concentration (IC50) of approximately 69μg/mL for HSV-1 and 49μg/mL for HSV-2. However, PSP-2B demonstrated no cytotoxicity even when its concentration was increased to 1600μg/mL, suggesting that it has potential as an anti-HSV drug candidate.

Keywords: Against herpes simplex virus activity; Arabinose (PubChem CID: 5460291); Galactose (PubChem CID: 439357); Galacturonic acid (PubChem CID: 84740); Glucose (PubChem CID: 5793); Glucuronic acid (PubChem CID: 441478); Mannose (PubChem CID: 18950); Prunellae Spica; Structural characterization; Sulphated polysaccharide.