Coproporphyrinogen I

Coproporphyrinogen I
Names
IUPAC name
3-[7,12,17-tris(2-carboxyethyl)-3,8,13,18-tetramethyl-5,10,15,20,21,22, 23,24-octahydroporphyrin-2-yl]propanoic acid
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1/C36H44N4O8/c1-17-21(5-9-33(41)42)29-14-26-19(3)23(7-11-35(45)46)31(39-26)16-28-20(4)24(8-12-36(47)48)32(40-28)15-27-18(2)22(6-10-34(43)44)30(38-27)13-25(17)37-29/h37-40H,5-16H2,1-4H3,(H,41,42)(H,43,44)(H,45,46)(H,47,48)
    Key: WIUGGJKHYQIGNH-UHFFFAOYAR
  • O=C(O)CCc1c(c5[nH]c1Cc2[nH]c(c(c2C)CCC(=O)O)Cc3c(c(c([nH]3)Cc4c(c(c([nH]4)C5)CCC(=O)O)C)CCC(=O)O)C)C
Properties
C36H44N4O8
Molar mass 660.757 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Coproporphyrinogen I is an isomer of coproporphyrinogen III, a metabolic intermediate in the normal biosynthesis of heme. The compound is not normally produced by the human body; its production and accumulation causes a type of porphyria. [1]

The difference between coproporphyrinogen I and III is the arrangements of the four carboxyethyl ("P" groups) and the four methyl groups ("M" groups). The I isomer has the sequence MP-MP-MP-MP, whereas in the III isomer it is MP-MP-MP-PM, with the last two side chains reversed.

Biosynthesys

Coproporphyrinogen I is not produced in the normal porphyrin biosynthesis pathway. However, if the enzyme uroporphyrinogen-III cosynthase is missing or inactive, the compound uroporphyrinogen I is produced instead of uroporphyrinogen III. The enzyme uroporphyrinogen III decarboxylase will also act on the I isomer, producing coproporphyrinogen I:[2][1]

The reaction entails the conversion of the four carboxymethyl (acetic acid) side chains to methyl groups, with release of four molecules of carbon dioxide.

Unlike the III isomer, coproporphyrinogen I (which is cytotoxic) is not further processed by the body, and accumulates. This situation occurs in the pathological condition called congenital erythropoietic porphyria.[1]

References

  1. ^ a b c S. Sassa and A. Kappas (2000): "Molecular aspects of the inherited porphyrias". Journal of Internal Medicine, volume 247, issue 2, pages 169-178. doi:10.1046/j.1365-2796.2000.00618.x
  2. ^ Paul R. Ortiz de Montellano (2008). "Hemes in Biology". Wiley Encyclopedia of Chemical Biology. John Wiley & Sons. doi:10.1002/9780470048672.wecb221. ISBN 978-0470048672.