Bilifuscin und Mesobilifuscin als natürliche Abbauprodukte des Blutfarbstoffes; über Vorkommen und Bildung

The Formation of Bilirubin From Hemoglobin in Vivo*

“…Although earlier investigators have suggested that dipyrrolic compounds, such as mesobilifuscin (7,44) and propentdyopent (44,45), may be normally occurring excretory products of heme metabolism, recent findings have failed to confirm this concept (46). The present experiments constitute strong evidence for the existence of alternate pathways of heme catabolism, but they do not establish the identity of the compounds involved.…”

The Preparation of Crystalline Bilirubin-C14*

“…Contrary to a widely held belief (75,87), however, the major oxidation product(s) was not biliverdin, but a diazonegative yellow intermediate(s) (88,89). This yellow color gradually faded and the solution became colorless.…”

“…In the present studies, however, dioxy-dipyrrylmethanes were formed in aqueous alkaline (88,89) and organic solutions of bilirubin in the absence of added hydrogen peroxide or other oxidizing agents (77). This suggests the possibility that a similar breakdown of bilirubin to dipyrrolic compounds may occur in the organism (77,92) or in the excreta (93,94), particularly after exposure to light (95,96).…”

“…Concomitantly, a strongly positive pentdyopent reaction developed, which indicated that some of the bilirubin had been converted to dioxy-dipyrrylmethanes or propentdyopent ( Figure 8) (88,89). Unlike bilirubin (90), these colorless breakdown products are very soluble in water (86,88), as illustrated by the appearance of most of the radioactivity in the propylene glycol-water phase after countercurrent distribution of the products obtained by illumination of (7,91). Therefore, after crystallizing bilirubin from methanol, it is desirable to separate quickly the formed crystals from the mother liquor by centrifugation.…”

Studies of the Dipyrrylmethene (“Fuscin”) Pigments. I. The Anabolic Significance of the Fecal Mesobilifuscin*

“…These and certain other samples were also recycled according to Siedel and M6ller's method after which ordinary and isotopic nitrogen percentages were again determined. 2 The method used in the fourth or normal subject (S. G.) was a modification of O~o cedure for isolation of mesobilifuscin (ogen) from feces. Most of the fecal samples from Subject 4 were first subjected to the ferrous hydroxide method for stercobilin isolation as previously described (13).…”