Über Mesobilifuscin, ein neues physiologisches Abbauprodukt des Häms bzw. Hämatins

Siedel, Walter; Möller, Hans

doi:10.1515/bchm2.1939.259.1-6.113

Cited by 46 publications

(9 citation statements)

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“…The results are compatible with the structures proposed for all six dipyrrolic products, as the agreement between the expected mass and the experimental value was very good (<10 ppm) for all of them. In contrast, a structure for the m/z 302 ion, as the radical cation of a bilifuscin (on the basis of the structure proposed in the literature18, 19), could not be validated by accurate mass, as the experimental value differed from the theoretical value by more than 70 ppm (results not shown).…”

Section: Resultsmentioning

confidence: 95%

Bilirubin degradation by uncoupled cytochrome P450. Comparison with a chemical oxidation system and characterization of the products by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Matteis¹,

Lord²,

Lim³

et al. 2006

Rapid Comm Mass Spectrometry

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Bilirubin is a protective antioxidant; however, when its conjugation and excretion are impaired, as in neonatal and hereditary jaundice, bilirubin accumulates and may cause severe neurotoxicity. Degradation of bilirubin takes place (a) on interaction with oxidative free radicals and (b) when cytochrome P450 (CYP) enzymes are uncoupled by polyhalogenated substrate analogues. The products of pathways (a) and (b) above have now been characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) and the mechanisms of fragmentation in part clarified. Oxidation of bilirubin by uncoupled CYP1A5 and by a Fe-EDTA/H2O2 system produced both biliverdin and an identical profile of dipyrrolic fragments, as detected by positive ESI-MS. A similar profile of oxidation products was found from mesobilirubin, all showing the expected increase in mass, thus providing direct evidence for fragmentation at the central methene bridge of the tetrapyrroles. Two degradation products, also detected by negative ESI-MS, were characterized as dipyrroles retaining the central bridge carbon, with one or two oxygen atom(s) bound (probably as the aldehyde and hydroperoxide derivatives). Ions compatible with propentdyopents and bilifuscins were also detected, but here the assignment was less certain. It is concluded that the first step in the oxidation of bilirubin may be hydrogen abstraction at the central methene bridge. This is followed either by loss of another hydrogen to give biliverdin, or by oxygen binding and fragmentation. Fe-EDTA/H2O2 and uncoupled CYP(Fe=O) may both initiate the reaction, the latter in an attempt to reduce the ferryl oxygen to water. These studies shed light on the CYP uncoupling mechanism and are of potential significance for the therapy of severe jaundice.

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Section: Resultsmentioning

confidence: 95%

Bilirubin degradation by uncoupled cytochrome P450. Comparison with a chemical oxidation system and characterization of the products by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Matteis¹,

Lord²,

Lim³

et al. 2006

Rapid Comm Mass Spectrometry

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“…On standing, this precipitate became darker, almost black. This method is a modification of the original procedure of Siedel and Moller (1939), and that described by Gilbertsen, Lowry, Hawkinson and Watson (1959) for the isolation of faecal dipyrrylmethenes. Elemental analysis, and solubility tests were carried out on esterified samples obtained in this way, and on unesterified pigments obtained by dialysing the urine against I per cent sodium carbonate and precipitating the pigment from the yellow solution with concentrated HC1 (Kreimer-Birnbaum, Pinkerton, Bannerman and Hutchison, 1966a).…”

Section: Urine Saniplesmentioning

confidence: 99%

Interrelationship of Pyrrole and Globin Metabolism in β‐Thalassaemia *

Kreimer‐Birnbaum

Bannerman

1968

Br J Haematol

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Detailed metabolic studies in a case of β‐thalassaemia intermedia following 14C‐2‐glycine administration demonstrate some of the interrelationships of pyrrole pigments and haemoglobins, and some secondary effects of a β‐thalassaemia mutation. Marked increase in the early‐labelled fraction of faecal bile pigment was confirmed; labelling rose to a maximum at 5 days, in advance of the haem peak, and was approximately three times greater than maximum haem labelling. Urinary coproporphyrins were increased in quantity, thus allowing complete serial determinations of radioactivity, which was at its maximum within 24 hours. The urine also contained a brown pigment, probably a dipyrrole, which had a labelling pattern resembling that of the urinary coproporphyrins, with maximum activity in the first sample. It is suggested that the ‘dipyrrole’may arise by early destruction of redundant haem associated with α‐chains. At all times, haemoglobin F was more highly labelled than haemoglobin A in both the haem and the globin moieties. Mean cell survival estimated graphically from the various curves was approximately 32 days. Haem/globin ratios were similar to those reported previously in normal subjects and in thalassaemia.

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“…In all of these the nitrogen determinations were made on the zinc precipitated material; hence the low values are due at least in part to zinc which may have been present in excess. Certain of the more important samples, in point of time, were analyzed for zinc 1 by the method of Vallee and associates (15,16). 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.…”

mentioning

confidence: 99%

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

Gilbertsen¹,

Lowry²,

Hawkinson³

et al. 1959

J. Clin. Invest.

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Über Mesobilifuscin, ein neues physiologisches Abbauprodukt des Häms bzw. Hämatins

Cited by 46 publications

References 0 publications

Bilirubin degradation by uncoupled cytochrome P450. Comparison with a chemical oxidation system and characterization of the products by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Bilirubin degradation by uncoupled cytochrome P450. Comparison with a chemical oxidation system and characterization of the products by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Interrelationship of Pyrrole and Globin Metabolism in β‐Thalassaemia *

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

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