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 PGF2α (IPG) resulted in the production of either PGF2α (nearly quantitatively) or PGF2α 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 PGF2α 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 PGF2α 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.