Bilirubin

"Billy Rubin" redirects here. For the American art scholar, see William Rubin.

Bilirubin
Names
IUPAC name
3,3′-(2,17-Diethenyl-3,7,13,18-tetramethyl-1,19-dioxo-10,19,21,22,23,24-hexahydro-1H-biline-8,12-diyl)dipropanoic acid
Systematic IUPAC name
3,3′-([12(2)Z,6(72)Z]-13,74-Diethenyl-14,33,54,73-tetramethyl-15,75-dioxo-11,15,71,75-tetrahydro-31H,51H-1,7(2),3,5(2,5)-tetrapyrrolaheptaphane-12(2),6(72)-diene-34,53-diyl)dipropanoic acid
Other names
Bilirubin IXα
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.010.218 Edit this at Wikidata
UNII
  • InChI=1S/C33H36N4O6/c1-7-20-19(6)32(42)37-27(20)14-25-18(5)23(10-12-31(40)41)29(35-25)15-28-22(9-11-30(38)39)17(4)24(34-28)13-26-16(3)21(8-2)33(43)36-26/h7-8,13-14,34-35H,1-2,9-12,15H2,3-6H3,(H,36,43)(H,37,42)(H,38,39)(H,40,41)/b26-13-,27-14- checkY
    Key: BPYKTIZUTYGOLE-IFADSCNNSA-N checkY
  • Key: BPYKTIZUTYGOLE-IFADSCNNBS
  • CC1=C(/C=C2C(C)=C(C=C)C(N/2)=O)NC(CC3=C(CCC(O)=O)C(C)=C(/C=C4C(C=C)=C(C)C(N/4)=O)N3)=C1CCC(O)=O
  • Cc1c(c([nH]c1/C=C\2/C(=C(C(=O)N2)C=C)C)Cc3c(c(c([nH]3)/C=C\4/C(=C(C(=O)N4)C)C=C)C)CCC(=O)O)CCC(=O)O
Properties
C33H36N4O6
Molar mass 584.673 g·mol−1
Density 1.31 g·cm-3[1]
Melting point 235°C[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Bilirubin (BR) (from the Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the destruction of aged or abnormal red blood cells.[3] In the first step of bilirubin synthesis, the heme molecule is stripped from the hemoglobin molecule. Heme then passes through various processes of porphyrin catabolism, which varies according to the region of the body in which the breakdown occurs. For example, the molecules excreted in the urine differ from those in the feces.[4] The production of biliverdin from heme is the first major step in the catabolic pathway, after which the enzyme biliverdin reductase performs the second step, producing bilirubin from biliverdin.[5][6]

Ultimately, bilirubin is broken down within the body, and its metabolites excreted through bile and urine; elevated levels may indicate certain diseases.[7] It is responsible for the yellow color of healing bruises and the yellow discoloration in jaundice. The bacterial enzyme bilirubin reductase is responsible for the breakdown of bilirubin in the gut.[8] One breakdown product, urobilin, is the main component of the straw-yellow color in urine.[9] Another breakdown product, stercobilin, causes the brown color of feces.

Although bilirubin is usually found in animals rather than plants, at least one plant species, Strelitzia nicolai, is known to contain the pigment.[10]

  1. ^ Bonnett, Raymond; Davies, John E.; Hursthouse, Michael B. (July 1976). "Structure of bilirubin". Nature. 262 (5566): 326–328. Bibcode:1976Natur.262..326B. doi:10.1038/262326a0. PMID 958385. S2CID 4278361.
  2. ^ Sturrock, E. D.; Bull, J. R.; Kirsch, R. E. (March 1994). "The synthesis of [10-13C]bilirubin IXα". Journal of Labelled Compounds and Radiopharmaceuticals. 34 (3): 263–274. doi:10.1002/jlcr.2580340309.
  3. ^ Braunstein E (3 May 2019). "Overview of Hemolytic Anemia – Hematology and Oncology". Merck Manuals Professional Edition (in Latin). Retrieved 5 May 2019.
  4. ^ "Bilirubin blood test", U.S. National Library of Medicine.
  5. ^ Boron W, Boulpaep E. Medical Physiology: a cellular and molecular approach, 2005. 984–986. Elsevier Saunders, United States. ISBN 1-4160-2328-3
  6. ^ Mosqueda L, Burnight K, Liao S (August 2005). "The life cycle of bruises in older adults". Journal of the American Geriatrics Society. 53 (8): 1339–43. doi:10.1111/j.1532-5415.2005.53406.x. PMID 16078959. S2CID 12394659.
  7. ^ Smith ME, Morton DG (2010). "LIVER AND BILIARY SYSTEM". The Digestive System. Elsevier. pp. 85–105. doi:10.1016/b978-0-7020-3367-4.00006-2. ISBN 978-0-7020-3367-4.
  8. ^ Hall, Brantley; Levy, Sophia; Dufault-Thompson, Keith; Arp, Gabriela; Zhong, Aoshu; Ndjite, Glory Minabou; Weiss, Ashley; Braccia, Domenick; Jenkins, Conor; Grant, Maggie R.; Abeysinghe, Stephenie; Yang, Yiyan; Jermain, Madison D.; Wu, Chih Hao; Ma, Bing (3 January 2024). "BilR is a gut microbial enzyme that reduces bilirubin to urobilinogen". Nature Microbiology. 9 (1): 173–184. doi:10.1038/s41564-023-01549-x. ISSN 2058-5276. PMC 10769871. PMID 38172624.
  9. ^ Chew, Dennis J.; DiBartola, Stephen P.; Schenck, Patricia A. (1 January 2011), Chew, Dennis J.; DiBartola, Stephen P.; Schenck, Patricia A. (eds.), "Chapter 1 - Urinalysis", Canine and Feline Nephrology and Urology (Second Edition), Saint Louis: W.B. Saunders, pp. 1–31, ISBN 978-0-7216-8178-8, retrieved 1 November 2023
  10. ^ Pirone C, Quirke JM, Priestap HA, Lee DW (March 2009). "Animal pigment bilirubin discovered in plants". Journal of the American Chemical Society. 131 (8): 2830. doi:10.1021/ja809065g. PMC 2880647. PMID 19206232.