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 54μM for HBeAg, 61μM for HBsAg and 2.66μM for supernatant HBV DNA, as compared to 1671, 1570, 169μM, 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 515.20μM. 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 7.08μM and toxicity with a CC(50) of 118.6μM against MDCK cells.