PORPHYRINS. 24. IDENTIFICATION OF ISOMERIC MONOESTERS OF NATURAL PORPHYRINS BY PMR SPECTROSCOPY

Article abstract of DOI:10.1007/BF00475598

The monomethyl esters of mono(dimethylamides) and the bisdimethylamides of mesoporphyrin-IX, mesoporphyrin-III, and mesoporphyrin-XIII have been obtained, together with their zinc complexes.A relationship has been found between the chemical shifts of the signals for CONMe2 in the PMR spectra and the positions of the substituents in the porphyrin ring, enabling a correct assignment to be made for the first time of these signals to the groups in positions 13² and 17² of the porphyrin ring, to establish the structures of the isomeric monomethyl esters of mesoporphyrin-IX, and to develop a method identifying monoesters of natural porphyrins by converting them into the monoesters of the mono(dimethylamides) of mesoporphyrin-IX, followed by examination of their PMR spectra.