Bilirubin

Bilirubin is the compound responsible for the yellow colour of bruises and urine. It is formed during the breakdown of red blood cells in animals.

Scientists at the Florida International University have now identified bilirubin in the Bird of Paradise plant. Using high-performance liquid chromatography (HPLC) and HPLC/electrospray ionization-tandem mass spectrometry, the scientists discovered bilirubin in the seeds and sepals of the plant.

Reference:
Pirone, Cary, Johnson, Jodie V., Quirke, J. Martin E., Priestap, Horacio A., Lee, David. The Animal Pigment Bilirubin Identified in Strelitzia reginae, the Bird of Paradise Flower. HortScience, 2010; 45: 1411-1415

Further Reading
Organic nomenclature
Functional groups
Chromatography

Study Questions

1. Give the molecular formula for the bilirubin molecule.
   
2. Identify the functional groups present in a molecule of bilirubin by circling them on the structure.
3. Name each of the functional groups above.
4. Is bilirubin an example of a saturated or an unsaturated organic molecule? Explain your answer.
5. Would you expect bilirubin to undergo a reaction with a mild oxidizing agent? Explain your answer.
6. Why do you think that bilirubin is a coloured compound?
7. Why do you think that scientists were initially surprised to find bilirubin in plants?