Figure 1:

Metabolic pathway of MPA. The salt mycophenolate mofetil is rapidly hydrolyzed by plasma and tissue esterases into the active form MPA. The UGT superfamily then converts MPA to either AcMPAG, an active minor metabolite, or MPAG, an inactive major metabolite. SLCO1B1/1B3 family of transporters help incorporate MPAG into bile where it is excreted into the intestines and gut bacteria hydrolyze it back to MPA for the enterohepatic circulation. A more detailed explanation of each protein is contained in the text. MPA: mycophenolic acid, UGT: uridine glucuronidasyl transferases, OATP: organic anion transporter protein, SLCO: soluble organic anion transporter, MRP-2: membrane resistance protein-2, IMPDH: inosine monophosphate dehydrogenase.