Small-Molecule Inhibitors for the Treatment of Hepatitis B Virus Documented in Patents

Hepatitis B virus (HBV) infection is a serious health problem worldwide, and the current treatment methods including vaccines, immunomodulators, interferons and nucleoside analogs are far from satisfactory. For the search of new anti-HBV agents, much investigation has revealed a large number of small-molecule compounds with various skeletons and promising anti-HBV activities. Although some reviews on anti-HBV progress have been published, they are mainly concentrated on the results reported in journal articles. This review provides an overview of the structural features and anti-HBV properties of the small-molecule anti-HBV inhibitors claimed in recent patents (from 2001 to 2010). These small-molecules can be structurally classified as two main types, nucleoside analogs (cyclic and acyclic nucleosides) and non-nucleosides (natural and synthesized compounds), which are declared with the activity inhibiting the secretion of HBsAg and HBeAg and HBV DNA replication in vitro, as well as anti-DHBV DNA in vivo. Especially, the nonnucleosides with diverse skeletons and novel mechanism offer prolific candidates for anti-HBV drug discovery, which are preferred to be used as adjuvant therapy for HBV infection. This paper will provide valuable information for understanding the current anti-HBV investigation and developing new anti-HBV agents.