vernolic acid

Vernonia oil is extracted from the seeds of the Vernonia galamensis (ironweed), a plant native to eastern Africa. The seeds contain about 40 to 42% oil of which 73 to 80% is vernolic acid. The best varieties of V. anthelmintica contain about 30% less vernolic acid.

Vernolic acid is not commonly found in plants in significant quantities, but some plants which do contain it are Vernonia, Stokesia, Crepis (from the daisy family), and Euphorbia lagascae and Bernardia pulchella from the Euphorbiaceae.{{cite journal | vauthors = Cahoon EB, Ripp KG, Hall SE, McGonigle B | title = Transgenic production of epoxy fatty acids by expression of a cytochrome P450 enzyme from Euphorbia lagascae seed | journal = Plant Physiology | volume = 128 | issue = 2 | pages = 615–24 | date = February 2002 | pmid = 11842164 | pmc = 148923 | doi = 10.1104/pp.010768 }}

Vernonia oil has been proposed as a precursor to adhesives, varnishes and paints, and industrial coatings. Its low viscosity recommends its use as a nonvolatile solvent in oil-based paints since it will become incorporated in the dry paint rather than evaporating into the air.''{{cite book | url = http://www.hort.purdue.edu/newcrop/afcm/vernonia.html | title = Alternative Field Crops Manual | chapter = Vernonia | vauthors = Teynor TM, Putnam DJ, Oplinger ES, Oelke EA, Kelling KA, Doll JD | access-date = 2006-09-10 | date = February 1992 }}

In its application as an epoxy oil,{{cite journal | url = http://www.hort.purdue.edu/newcrop/proceedings1999/v4-272.html | vauthors = Mohamed AI, Mebrahtu T, Andebrhan T | year = 1999 | title = Variability in oil and vernolic acid contents in the new Vernonia galamensis collection from East Africa | pages = 272–274 | veditors = Janick J | journal = Perspectives on New Crops and New Uses | access-date = 2006-09-10 }} vernonia oil competes with soybean or linseed oil, which supply most of the market for these applications. Its low viscosity makes it more desirable than fully epoxidized linseed or soybean oils. It is comparable to partially epoxidized linseed or soybean oil.{{cite journal | last1 = Muturi | first1 = Patrick | last2 = Wang | first2 = Danqing | last3 = Dirlikov | first3 = Stoil | name-list-style = vanc | title = Epoxidized vegetable oils as reactive diluents I. Comparison of vernonia, epoxidized soybean and epoxidized linseed oils | journal = Progress in Organic Coatings | volume = 25 | pages = 85–94 | year = 1994 | doi = 10.1016/0300-9440(94)00504-4 }}

In a variety of mammalian species, vernolic acid is made by the metabolism of linoleic acid by cytochrome P450 epoxygenase enzymes; under these circumstances it is termed leukotoxin because of its toxic effects on leukocytes and other cell types and of its ability to produce multiple organ failure and respiratory distress when injected into rodent animal models of the acute respiratory distress syndrome.{{cite journal | vauthors = Linhartová I, Bumba L, Mašín J, Basler M, Osička R, Kamanová J, Procházková K, Adkins I, Hejnová-Holubová J, Sadílková L, Morová J, Sebo P | title = RTX proteins: a highly diverse family secreted by a common mechanism | journal = FEMS Microbiology Reviews | volume = 34 | issue = 6 | pages = 1076–112 | date = November 2010 | pmid = 20528947 | pmc = 3034196 | doi = 10.1111/j.1574-6976.2010.00231.x }}{{cite journal | vauthors = Spector AA, Kim HY | title = Cytochrome P450 epoxygenase pathway of polyunsaturated fatty acid metabolism | journal = Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids | volume = 1851 | issue = 4 | pages = 356–65 | date = April 2015 | pmid = 25093613 | pmc = 4314516 | doi = 10.1016/j.bbalip.2014.07.020 }}{{cite journal | pmid = 22715155 | pmc = 3413237 | year = 2012 | last1 = Edwards | first1 = L. M. | title = Metabolomics reveals increased isoleukotoxin diol (12,13-DHOME) in human plasma after acute Intralipid infusion | journal = The Journal of Lipid Research | volume = 53 | issue = 9 | pages = 1979–86 | last2 = Lawler | first2 = N. G. | last3 = Nikolic | first3 = S. B. | last4 = Peters | first4 = J. M. | last5 = Horne | first5 = J | last6 = Wilson | first6 = R | last7 = Davies | first7 = N. W. | last8 = Sharman | first8 = J. E. | doi = 10.1194/jlr.P027706 |doi-access=free }} These effects appear due to the conversion of vernolic acid to its dihydroxy counterparts. For instance, (12S,13R)-EpOME is converted by soluble epoxide hydrolase (sEH) to (12R,13R)-dihydroxy-9Z-octadecenoic acid due to inversion at C12 carbon atom during hydrolysis. A mixture of this dihydroxy acid with its 12S,13S enantiomer has been termed isoleukotoxin diol.{{cite journal | vauthors = Greene JF, Newman JW, Williamson KC, Hammock BD | title = Toxicity of epoxy fatty acids and related compounds to cells expressing human soluble epoxide hydrolase | journal = Chemical Research in Toxicology | volume = 13 | issue = 4 | pages = 217–26 | date = April 2000 | pmid = 10775319 | doi = 10.1021/tx990162c }}{{cite journal |title=Bioactivation of leukotoxins to their toxic diols by epoxide hydrolase |vauthors=Moghaddam MF, Grant DF, Cheek JM, Greene JF, Williamson KC, Hammock BD |date=May 1997 |journal=Nature Medicine |volume=3 |number=5 |publisher=Nature Publishing Group |pages=562–566 |doi=10.1038/nm0597-562 |pmc=7095900 |pmid=9142128 }}{{rp|at=Fig. 1|q=threo means R,R and/or S,S enantiomers}} Some studies suggest but have not yet proven that vernolic acid is responsible for or contributes to multiple organ failure, respiratory distress, and certain other cataclysmic diseases in humans (see {{slink|Epoxygenase|Linoleic acid}}).

• coronaric acid, C9-C10 epoxide of linoleic acid.

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Category:Vegetable oils

Category:Fatty acids

Category:Epoxides

Category:Alkenoic acids