It is acted upon by its namesake oxyreductase and, like phytochrome, consists of a tetrapyrrole, though it does not form a porphyrin ring like heme.  
This compound's direct form is prefixed with the term "azo," and very high levels of it can induce Dubin-Johnson or Crigler-Najjar syndromes.  It is acted upon by its namesake oxyreductase and, like phytochrome, consists of a tetrapyrrole, though it does not form a porphyrin ring like heme.  It is made soluble in water when conjugated with glucuronic acid, which can then be metabolized to stercobilinogen by bacteria in the colon. It is formed in the body when erythrocytes undergo heme catabolism, and its light sensitivity results in a water-soluble isomer that mitigates jaundice in newborns.  FTP, identify this compound that gives a yellow-brown color to bile.
This compound's direct form is prefixed with the term "azo," and very high levels of it can induce Dubin-Johnson or Crigler-Najjar syndromes.  
bilirubin