porphobilin

por·pho·bi·lin

(pōr'fō-bī'lin),
General term denoting intermediates between the monopyrrole, porphobilinogen, and the cyclic tetrapyrrole of heme (a porphin derivative).
See also: bilin.
Farlex Partner Medical Dictionary © Farlex 2012

por·pho·bi·lin

(pōr'fō-bī'lin)
General term denoting intermediates between the monopyrrole, porphobilinogen, and the cyclic tetrapyrrole of heme (a porphin derivative).
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Urine porphobilinogen is converted to porphyrin and porphobilin, which when exposed to air and light, cause the urine to turn dark (2).
In AIP and other acute porphyrias, urine that is light in color on voiding may darken when exposed to light and air due to polymerization of colorless PBG to uroporphyrin and porphobilin. In porphyria cutanea tarda (PCT), voiding of urine that is already discolored owing to increased uroporphyrins is expected.
PBG in urine undergoes in vitro conversion to the red pigment, uroporphyrin (present mainly as its zinc chelate), and to porphobilin, an as-yet-uncharacterized brown oxidation product of PBG.