Figure 5. Chemical structures of A: cAMP, B: cAMP with substituents that favor inhibition of OATP1B1 and 1B3, and C: substituents that do not interfere with OATP-activity.

The structure in A shows the numbering of the atoms. The substituents in B and C are i: N⁶-phenyl, ii: 8-para-chlorophenylthio, iii: 2′-O-methyl, iv: acetoxymethyl ester, v: N⁶-monobutyryl, vi: 8-bromo.