Fig. 3.

Tertiary structure of HCV NS5A and structural formulas of approved or experimental NS5A inhibitors from (19) to (36). Two units of an NS5A dimer are colored by pink and cyan, respectively. NS5A inhibitor daclatasvir is also illustrated. Blue arrows indicate the optimization from initial compounds to FDA-approved compounds such as ombitasvir (DeGoey et al., 2014), ledipasvir (Link et al., 2014), daclatasvir (Belema and Meanwell, 2014), and elbasvir (Coburn et al., 2013). Other NS5A inhibitors are summarized in Table 20.