The methanol adduct of dimethyl ester of propentdyopent, which have two carboxyl groups on two pyrrole rings, was prepared by the oxidation of hemin with hydrogen peroxide and following esterification with a mixture of methanol and sulfuric acid. The compound was purified by the preparative column chromatography with silica gel and following recrystallization. The purity was checked by thin-layer chromatography and high-performance liquid chromatography. The compound was identified with mass and nuclear magnetic resonance spectra.