Phosphonylmethoxyalkyl derivatives of purine as inhibitors of human hepatitis B virus DNA synthesis.

A selected number of antiviral compounds which have been previously shown to inhibit the replication of DNA viruses or retroviruses were examined for their inhibitory effects on human hepatitis B virus (HBV) DNA synthesis. The assay system was based on the use of a human hepatoblastoma cell line (HB611) that continuously synthesizes HBV DNA. The following phosphonylmethoxyalkyl-purine derivatives were found to inhibit HBV DNA synthesis: 9-(2-phosphonyl-methoxyethyl)-2',6'-diaminopurine (PMEDAP), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA). PMEDAP, HPMPA and PMEA not only inhibit HBV DNA synthesis in HB611 cells but also duck hepatitis B virus (DHBV) DNA and core antigen synthesis in primary duck hepatocytes.