Electrochemical investigation on prostaglandin F2α derivatives. II. Cathodic reduction of the iodinated prostaglandin F2α and its methyl ester

Based on voltammetric studies, preparative controlled potential reduction on an Hg cathode of iodinated PGF₂ (IPG) resulted in the production of either PGF₂ (nearly quantitatively) or PGF₂ and the biologically active PGI₁ (in a 2:3 ratio at maximum), depending on the medium and the potential used. The 5-Z isomer percentage in the PGF₂ thus formed varied between 50 and 60, while originally, before the anodic iodination and the subsequent reduction of IPG, this ratio was 98%. The electrochemically formed PGI₁ contained 95% 6-S and 5% 6-R isomer. In any selected medium the first voltammetric wave can be ordered to PGF₂ formation, and that of the second wave (in aqueous and non-aqueous media) to PGI₁ formation. On the basis of the experimental results a mechanism is proposed for the electroreduction process in aqueous media.