Coronaric acid

Coronaric acid

Names
IUPAC name 8-[3-[(Z)-Oct-2-enyl]oxiran-2-yl]octanoic acid
Other names 9,10-Epoxy-12Z-octadecenoic acid; 9(10)-EpOME
Identifiers
3D model (JSmol)	Interactive image
PubChem CID	6246154
InChI InChI=1S/C18H32O3/c1-2-3-4-5-7-10-13-16-17(21-16)14-11-8-6-9-12-15-18(19)20/h7,10,16-17H,2-6,8-9,11-15H2,1H3,(H,19,20)/b10-7- Key: FBUKMFOXMZRGRB-YFHOEESVSA-N
SMILES CCCCC/C=C\CC1C(O1)CCCCCCCC(=O)O
Properties
Chemical formula	C18H32O3
Molar mass	296.45 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Coronaric acid (isoleukotoxin) is a mono-unsaturated, epoxide derivative of the di-saturated fatty acid, linoleic acid (i.e. 9(Z),12(Z) octadecadienoic acid. It is a mixture of the two optically active isomers of 12(Z) 9,10-epoxy-octadecenoic acid. This mixture is also termed 9,10-epoxy-12Z-octadecenoic acid or 9(10)-EpOME and when formed by or studied in mammalians, isoleukotoxin.

Coronaric acid is found in the seed oils derived from plants in sunflower family such as (Helianthus annuus) and Xeranthemum annuum.

Coronaric acid is also formed by the cells and tissues of various mammalian (including humans) species through the metabolism of linoleic acid by (CYP) epoxygenase enzymes. These CYPs (CYP2C9 and probably other CYPs that metabolize polyunsaturated fatty acids to epoxides) metabolize linoleic acid to (+)12S,13R-epoxy-9(Z)-octadecaenoic acid and (-)12R,13S-epoxy-9(Z)-octadecaenoic acid, i.e. the (+) and (-) epoxy optical isomers of coronaric acid. When studied in this context, the optical isomer mixture is often termed isoleukotoxin. This same CYP epoxygenases concurrently attack linoleic acid at the carbon 9,10 rather than 12,13 double bond of linoleic acid to form a mixture of (+) and (-) epoxy optical isomers viz., 9S,10R-epoxy-12(Z)-octadecaenoic and 9R,10S-epoxy-12(Z)-octadecaenoic acids. This (+) and (-) optical mixture is often termed vernolic acid or when studied in plants and leukotoxin when studied in mammals.

Coronoric acid is found in urine samples from healthy human subjects and increases 3- to 4-fold when these subjects are treated with a salt-loading diet.

Coronaric and vernolic acids also form non-enzymatically when linoleic acid is exposed to oxygen and/or UV radiation as a result of the spontaneous process of autooxidation. This autoxidation complicates studies in that it is often difficult to determine if these epoxy fatty acids identified in linoleic acid-rich plant and mammalian tissues represent actual tissue contents or are artifacts formed during their isolation and detection.