Abstract: The title compound was extracted and synthesized from pig blood.Its coordination reduc-tion reactions with organic bases have been studied using spectral technique.The factorsaffecting the activity of coordination reduction were examined in comparison with otherporphyrin manganese (Ⅲ).The results demostrate that (a) the porphyrin ring with strongelectron-attracting groups is favor of the coordination reduction, (b) the namber of organicbase molecules participated in reaction depends on the structure of porphyrin, (c) orgapicbases studied gave the following reducing power: piperidine, n-propylamine>pyridine>imi-dazole.

Key words: Photodimethylesterprotoporphyrin manganese(Ⅲ)chloride, piperidine, n-propylamine, pyridine, imidazole