FIG 2.

Proposed cellular metabolism of ATI-2173. (A) Structure of ATI-2173 and 5 metabolites found in hepatocytes of mouse, rat, dog, monkey, and human. (B) Relative abundance of each metabolite as a percentage of the total. In human hepatocytes, the parent compound (ATI-2173), major metabolite (M1), and clevudine-5′-monophosphate (MP) are indicated in blue. (C) ATI-2173 generates the major metabolite, M1, via CES-1/Cath A and a series of nonenzymatic rapid chemical reactions. M1 is then converted into MP putatively via HINT-1, where it follows normal clevudine metabolism to generate the active clevudine-5′-triphosphate.