Zwischenprodukte der Umwandlung von Häminen in Gallenfarbstoffe

Abstract

A green bile pigment is obtained by the action of yeast on a pyridine soln. of hemin, by the action of 0 on a pyridine soln. of hydrazine and protohemin, etc. To study the characteristics of this green pigment, coproverdohemin ester is reduced in hot formic acid (70[degree]-75[degree]) in H with Pd as catalyzer. Coproporphyrin 1-tetramethyl ester and copro-glaucobilin ester, m. 202[degree], are obtained. A red violet pigment, which cannot be crystallized, is obtained by oxidation of copropyridine-hemochromogen ester with H2O2. The spectrum of its red fluorescing Zn salt is identical with that of the Zn salt of dimethoxyetioglaucobilin. A new method for the prepn. of meso dimethyl ester pyridine-hemochromogen consists in dissolving 3 g. mesohemin ester in 30 ml. pyridine at 80[degree], cooling the mixture to 60[degree], adding 8 ml. of hydrazine hydrate-H2O (1:10) and 10 ml. H2O. After cooling, 3 g. of the hemochromogen are obtained. By benzoylation, the color of the compound is shifted from green towards red. The benzoxymesoporphyrin ester consists of 4 isomers, which are formed by oxidation at various methine bridges. Benzoxymesoporphyrin dimethyl ester forms a Zn complex salt, undergoes catalytic hydro-genation in the presence of Pd., and a hydroxymesopor-phyrin dimethyl ester may be formed from it. The latter compound may be converted into benzoxymesoporphyrin ester dimethyl ester or hydroxymesohemin dimethyl ester, which is then converted into a mixture of bile pigments. Protohemin dimethyl ester is converted into protodimethyl ester pyridine-hemochromogen, from which benzoxyproto-porphyrin dimethyl ester and benzoxymesoporphyrin dimethyl ester are obtained. Methods are also given for the preparaton of hydroxyprotoporphyrin dimethyl ester, ben-zoxyprotoporphyrin dimethyl ester, hydroxyprotohemin dimethyl ester, rhodo dimethyl ester pyridine-hemochromogen, benzoxy rhodoporphyrin dimethyl ester, phylloester pyridine-hemochromogen, and benzoxy- and hydroxyphyllo-porphyrin methyl ester.