4404 Bilirubin Bilirubin is a bile pigment that is a degradation product of heme. In particular, bilirubin is a yellow breakdown product of normal heme catabolism. Its levels are elevated in certain diseases and it is responsible for the yellow color of bruises. Bilirubin is an excretion product, and the body does not control levels. Bilirubin levels reflect the balance between production and excretion. Thus, there is no normal level of bilirubin. Bilirubin consists of an open chain of four pyrroles (tetrapyrrole); by contrast, the heme molecule is a closed ring of four pyrroles, called porphyrin. 635-65-4 5280352 C33H36N4O6 White powder. 0.009 mg/mL at 25°C No indication of carcinogenicity to humans (not listed by IARC). This is an endogenously produced metabolite found in the human body. It is used in metabolic reactions, catabolic reactions or waste generation. 2014-08-29T06:31:48Z 2026-05-14T20:14:27Z Bilirubin C00486 16990 BILIRUBIN DB19429 true CC1=C(C=C)\C(NC1=O)=C\C1=C(C)C(CCC(O)=O)=C(CC2=C(CCC(O)=O)C(C)=C(N2)\C=C2/NC(=O)C(C=C)=C2C)N1 C33H36N4O6 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- BPYKTIZUTYGOLE-IFADSCNNSA-N 584.6621 584.263484904 Endogenous Solid HMDB00054 CHEMBL501680 4444055 CHEM003310 DTXSID8060905 NS00014797 164.37999999999997 168.89600000000002 65.37085348816531 12 6 6 4.027490824017337 -2.754561928374644 -2 4 3.22 -4.78 9.64e-03 g/l