trans-4,5-Epoxy-(E)-2-decenal

trans-4,5-Epoxy-(E)-2-decenal (E2D)is an oxygenated α,β-unsaturated aldehyde found in mammalian blood that gives blood its characteristic metallic odor. It is used by predators to locate blood or prey.[1] trans-4,5-Epoxy-(E)-2-decenal is almost certainly found in all mammals.[2] Humans can smell it at a concentration of 1.5 pg/L in air,[3] at 15 ng/L in water and 1.3μg/L in oil.[4] It was permitted as a food flavouring in the EU until it was prohibited on 11 July 2017[5] on the grounds of possible genotoxicity, as observed from rat livers.[6]

trans-4,5-Epoxy-(E)-2-decenal
3D model of the trans-4,5-Epoxy-(E)-2-decenal molecule.
Names
Other names
3-[(2R,3R)-3-Pentyloxiranyl]-2E-propenal; Epoxy-2-decenal
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C10H16O2/c1-2-3-4-6-9-10(12-9)7-5-8-11/h5,7-10H,2-4,6H2,1H3/b7-5+/t9-,10+/m0/s1
    Key: HIOMEXREAUSUBP-FNORWQNLSA-N
  • CCCCCC1OC1\C=C\C=O
Properties
C10H16O2
Molar mass 168.236 g·mol−1
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H225, H319, H336 EUH066
P210, P261, P264, P280, P303+P361+P353, P304+P340, P305+P351+P338, P312, P337+P313
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

It can be formed during baking fats that contain linoleic acid. 13-Hydroperoxy-9,11-octadecadienoic acid and 9-hydroperoxy-10,12-octadecadienoic acid are intermediates in the process.[7] The aldehyde also forms in cooked beef when it sits in the refrigerator for too long contributing to a stale smell.[8] It is also an important part of the smell of raw and cooked mutton.[9]

Humans are more sensitive to the smell of trans-4,5-Epoxy-(E)-2-decenal than mice.[10]

References

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  1. ^ "Odor that smells like blood: Single component powerful trigger for large carnivores". Physorg. 11 November 2014. Retrieved 11 November 2014.
  2. ^ Arshamian, Artin; Laska, Matthias; Gordon, Amy R.; Norberg, Matilda; Lahger, Christian; Porada, Danja K.; Jelvez Serra, Nadia; Johansson, Emilia; Schaefer, Martin; Amundin, Mats; Melin, Harald; Olsson, Andreas; Olsson, Mats J.; Stensmyr, Marcus; Lundström, Johan N. (20 October 2017). "A mammalian blood odor component serves as an approach-avoidance cue across phylum border - from flies to humans". Scientific Reports. 7 (1). doi:10.1038/s41598-017-13361-9. PMC 5651850.
  3. ^ Lin, Jianming; Laurent B. Fay; Dieter H. Welti; Imre Blank (2001). "Quantification of key odorants formed by autoxidation of arachidonic acid using isotope dilution assay". Lipids. 36 (7): 749–756. doi:10.1007/s11745-001-0781-x. ISSN 0024-4201. PMID 11521974. S2CID 3979031.
  4. ^ Lin, Jianming; Laurent B. Fay; Dieter H. Welti; Imre Blank (1999). "Synthesis of trans-4,5-epoxy-(E)-2-decenal and its deuterated analog used for the development of a sensitive and selective quantification method based on isotope dilution assay with negative chemical ionization". Lipids. 34 (10): 1117–1126. doi:10.1007/s11745-999-0463-8. ISSN 0024-4201. PMID 10580339. S2CID 4054911.
  5. ^ "COMMISSION REGULATION (EU) 2017/1250 of 11 July 2017 amending Annex I to Regulation (EC) No 1334/2008 of the European Parliament and of the Council as regards removal from the Union list of the flavouring substance 4,5-epoxydec-2(trans)-enal". Official Journal of the European Union. 11 July 2017.
  6. ^ EFSA CEF Panel (2017). "Scientific Opinion on Flavouring Group Evaluation 226 Revision 1 (FGE.226Rev1): consideration of genotoxicity data on one α,β-unsaturated aldehyde from chemical subgroup 1.1.1(b) of FGE.19". EFSA Journal. 15 (5): 4847–4871. doi:10.2903/j.efsa.2017.4847. PMC 7010128. PMID 32625501.
  7. ^ Gassenmeier, Klaus; Peter Schieberle (1994). "Formation of the intense flavor compound trans-4,5-epoxy-(E)-2-decenal in thermally treated fats". Journal of the American Oil Chemists' Society. 71 (12): 1315–1319. doi:10.1007/BF02541347. ISSN 0003-021X. S2CID 85079936.
  8. ^ Konopka, Ute Christine; Werner Grosch (1991). "Potent odorants causing the warmed-over flavour in boiled beef". Zeitschrift für Lebensmittel-Untersuchung und -Forschung. 193 (2): 123–125. doi:10.1007/BF01193360. ISSN 0044-3026. S2CID 83249703.
  9. ^ Rota, Valerie; Peter Schieberle (2005). "Changes in Key Odorants of Sheep Meat Induced by Cooking". Food Lipids. ACS Symposium Series. Vol. 920. pp. 73–83. doi:10.1021/bk-2005-0920.ch006. ISBN 0-8412-3896-0. ISSN 1947-5918.
  10. ^ McGann, John P. (11 May 2017). "Poor human olfaction is a 19th-century myth". Science. 356 (6338): eaam7263. doi:10.1126/science.aam7263. PMC 5512720. PMID 28495701.