Crystal and Molecular Structures of Monomethyl Esters of PDE-I and PDE-II, New Inhibitors of Cyclic Adenosine-3′,S′-monophosphate Phosphodiesterase

The structures of PDE-I and PDE-II, inhibitors of cyclic adenosine-3′,5′-monophosphate phosphodiesterase, were established as 3-carbamoyl-l,2-dihydro-4-hydroxy-5-methoxy-3-H-pyrrolo[3,2-e]indole-7-carboxylic acid and its 3-acetyl homologue, by X-ray diffraction study of monomethyl derivatives.