Eoxin E4 (EXE4), also known as 14,15-leukotriene E4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(S)-hydroperoxyeicosapentaenoic acid (i.e. 15(S)-HpETE). This product is then converted serially to EXA4, EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows:[1][2]

Eoxin E4
Names
IUPAC name
(5Z,8Z,10E,12E,14R,15S)-14-{[(2R)-2-Amino-2-carboxyethyl]sulfanyl}-15-hydroxy-5,8,10,12-icosatetraenoic acid
Other names
EXE4; 14,15-LTE4; 14,15-Leukotriene E4
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
  • InChI=1S/C23H37NO5S/c1-2-3-12-15-20(25)21(30-18-19(24)23(28)29)16-13-10-8-6-4-5-7-9-11-14-17-22(26)27/h4,6-10,13,16,19-21,25H,2-3,5,11-12,14-15,17-18,24H2,1H3,(H,26,27)(H,28,29)/b6-4-,9-7-,10-8+,16-13+/t19-,20-,21+/m0/s1
    Key: JLJNENVYAVKECZ-HRXVJLLUSA-N
  • InChI=1/C23H37NO5S/c1-2-3-12-15-20(25)21(30-18-19(24)23(28)29)16-13-10-8-6-4-5-7-9-11-14-17-22(26)27/h4,6-10,13,16,19-21,25H,2-3,5,11-12,14-15,17-18,24H2,1H3,(H,26,27)(H,28,29)/b6-4-,9-7-,10-8+,16-13+/t19-,20-,21+/m0/s1
    Key: JLJNENVYAVKECZ-HRXVJLLUBX
  • CCCCC[C@@H]([C@@H](/C=C/C=C/C=C\C/C=C\CCCC(=O)O)SC[C@@H](C(=O)O)N)O
Properties
C23H37NO5S
Molar mass 439.61 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Arachidonic acid + O2 → 15(S)-HpETE → EXA4 → EXC4 → EXD4 → EXE4

EXA4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the downstream eoxins. The eoxins downstream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see eoxins).[1][3]

References

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  1. ^ a b Claesson HE (September 2009). "On the biosynthesis and biological role of eoxins and 15-lipoxygenase-1 in airway inflammation and Hodgkin lymphoma". Prostaglandins Other Lipid Mediat. 89 (3–4): 120–5. doi:10.1016/j.prostaglandins.2008.12.003. PMID 19130894.
  2. ^ Greene ER, Huang S, Serhan CN, Panigrahy D (2011). "Regulation of inflammation in cancer by eicosanoids". Prostaglandins & Other Lipid Mediators. 96 (1–4): 27–36. doi:10.1016/j.prostaglandins.2011.08.004. PMC 4051344. PMID 21864702.
  3. ^ Feltenmark S, Gautam N, Brunnström A, Griffiths W, Backman L, Edenius C, Lindbom L, Björkholm M, Claesson HE (2008). "Eoxins are proinflammatory arachidonic acid metabolites produced via the 15-lipoxygenase-1 pathway in human eosinophils and mast cells". Proceedings of the National Academy of Sciences of the United States of America. 105 (2): 680–5. Bibcode:2008PNAS..105..680F. doi:10.1073/pnas.0710127105. PMC 2206596. PMID 18184802.