Urobiline

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Structural formula of D-urobilin
Structural formula of I-urobilin
Structural formula of L-urobilin

Urobilins or mesobilins are bile pigments and breakdown products of hemoglobin and contribute to the color of the faeces of most mammals . They arise in the intestine through the oxidation of bilirubin via the intermediate stage of the colorless urobilinogens . Despite their name, the urobilins are only marginally involved in the coloration of urine ; they are therefore less part of the urochromes ( urine pigments ) than the coprochromes ( fecal pigments ).

The normal amount of urobilins excreted daily in the faeces and urine is around 150 mg. Liver disease or haemolysis can lead to increased excretion of urobilin, while a blockage of the biliary tract is shown by a reduced or absent amount in urine and feces.

Individual evidence

  1. ^ Wissenschaft-Online-Lexika: Entry on urobilin in the Lexikon der Biologie , accessed July 3, 2008.
  2. ^ A b F. Hoffmann-La Roche, Urban & Fischer, D. Reiche: Roche Lexicon Medicine. S. 1889, Basel, 2003, Elsevier-Verlag , ISBN 3437151509 .
  3. A. Gossauer: Structure and reactivity of the biomolecules: An introduction to organic chemistry. P. 474, 2003, Helvetica Chimica Acta, ISBN 3-90639029-2 .

Web links

Wikibooks: Breakdown of Porphyrin to Urobilins  - Learning and Teaching Materials