Lumirubin is a structural
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...
of
bilirubin
Bilirubin (BR) (adopted from German, originally bili—bile—plus ruber—red—from Latin) is a red-orange compound that occurs in the normcomponent of the straw-yellow color in urine. Another breakdown product, stercobilin, causes the brown ...
, which is formed during
phototherapy
Light therapy, also called phototherapy or bright light therapy is the exposure to direct sunlight or artificial light at controlled wavelengths in order to treat a variety of medical disorders, including seasonal affective disorder (SAD), circ ...
used to treat
neonatal jaundice
Neonatal jaundice is a yellowish discoloration of the white part of the eyes and skin in a newborn baby due to high bilirubin levels. Other symptoms may include excess sleepiness or poor feeding. Complications may include seizures, cerebral ...
. This polar isomer resulting from the blue-green lights of phototherapy has an active site to albumin, and its effects are considered less toxic than those of bilirubin. Lumirubin is excreted into bile or urine. ZZ, ZE, EE and EZ are the four structural isomers of bilirubin. ZZ is the stable, more insoluble form. Other forms are relatively soluble and are known as lumirubins. Phototherapy converts the ZZ form into lumirubins. Monoglucuronylated lumirubins are easily excreted.
References
Hepatology
Tetrapyrroles
{{biochem-stub