Purification, characterization and antiviral activity of two heteropolysaccharides from Duchesneae Indicae

This study was designed to uncover the antiviral compounds contained in Duchesneae Indicae. Two non-sulfated acidic heteropolysaccharides (DIP30 and DIP60) with anti-varicella-zoster virus (anti-VZV) activity were purified and investigated with a combination of DEAE C-52 ion-exchange chromatography, Sphacryl S-300 gel chromatography, high performance size exclusion chromatography, pre-column derivation with 1-phenyl-3-methyl-5-pyrazolone (PMP) method, infrared (IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR). Results indicated that molecular weight (MW) of DIP30 and DIP60 are 1.98 × 103 kDa and 34 kDa, respectively. Both DIP30 and DIP60 have a backbone of β-conformation and consist of more than four kinds of monosaccharides. The anti-VZV 50% effective concentrations (EC50) of DIP30 and DIP60 are 265.2 ± 35.4 μg/ml and 325.6 ± 42 μg/ml, respectively, suggesting that DIP30 and DIP60 could be explored as novel antiviral agents.