In vitro anti-hepatitis B and SARS virus activities of a titanium-substituted-heteropolytungstate

A structural determined heteropolytungstate, [K(4)(H(2)O)(8)Cl][K(4)(H(2)O)(4)PTi(2)W(10)O(40)]·NH(2)OH 1, has been synthesized and evaluated for in vitro antiviral activities against hepatitis B (HBV) and SARS virus. The identity and high purity of compound 1 were confirmed by elemental analysis, NMR, IR analysis and single-crystal X-ray diffraction. The compound 1, evaluated in HepG 2.2.15 cells expressing permanently HBV, significantly reduced the levels of HBV antigens and HBV DNA in a dose-dependent and time-dependent manner. EC(50) values were determined to be 54 μM for HBeAg, 61 μM for HBsAg and 2.66 μM for supernatant HBV DNA, as compared to 1671, 1570, 169 μM, respectively, for the commercially-available hepatitis B drug adefovir dipivoxil (ADV). Intracellular cccDNA, pgRNA and HBcAg were also found to be decreased by compound 1 in a concentration-dependent manner. Cytotoxicity results showed that compound 1 has low toxicity in HepG 2 cells with CC(50) value of 515.20 μM. The results indicate that compound 1 can efficiently inhibit HBV replication in HepG 2.2.15 cells line in vitro. Additionally, compound 1 also shows high anti-SARS activity at an EC(50) of 7.08 μM and toxicity with a CC(50) of 118.6 μM against MDCK cells.