Euphorbia lagascae Vemolic acid

Epoxidised oils (with isolated double bonds), such as epoxidised soybean are used as plasticisers. The natural occurrence of epoxidised fatty acids could be exploited to reduce processing costs on the pathway to polymerisation. For example, seed oils derived from Vernonia galamensis and Euphorbia lagascae both contain significant proportions (60-80%) of the epoxy acid vemolic acid, with interesting applications in greases and polyurethane applications (Turley et al., 2000). 

Oils containing epoxy acids Several natural epoxy acids are known, but vernolic acid (12,13-epoxyoleic) is the most common and occurs at high levels in several seed oils. Of these, serious attempts are now being made to develop Vernonia galamensis (73-78% vemolic acid) and Euphorbia lagascae (57-62% vernolic acid) as commercial crops (198). Several potential uses of this acid and the seed oils in which it occurs are being explored. 

Another interesting oilseed crop tiiat has been researched in our laboratories for several years is Euphorbia lagascae (22) (Fig. 3). This oilseed crop contains vemolic acid (12,13 -epoxy-cis-9-octadecenoic acid), with a natural epoxide content of 65% (see Table 2). 

Dihydroxyoleic acid (30) (Fig. 2.15) is formed from vemolic acid (39) (which, in turn, is formed from linoleic acid) in crushed seeds of Xeranthemum annuum (As-teraceae) and Euphorbia lagascae (Euphorbiaceae). 

Epoxy fatty acids also are found as components of triglycerides of the seed oils (Smith, 1970). This unusual fatty acid type is sporadically distributed in species of several taxo-nomically unrelated plant families. Z-12,13-Epoxyoleic acid (vemolic acid) (39) (Fig. 2.15) is biosynthesized from linoleic acid in the seeds of Xemnthemum anmum and Euphorbia lagascae (Hitchcock and Nichols, 1971). This compound and Z-9,10-epoxy stearate are synthesized by the introduction of oxygen from O2 across the double bonds of linoleic and oleic acids, respectively (Butt and Lamb, 1981 Morris, 1970). The biosynthesis of epoxy fatty acids is related to that of dihydroxy fatty acids, and epoxy fatty acids may serve as precursors for the latter type of compound. 

Pascual-Villalobos, M.J., Robbelen, G., Correal, E., Witzke, E-von, 1993. Performance test of Euphorbia lagascae Spreng., an oilseed species rich in vemolic acid, in southeast Spain. Ind. Crops Prod. 1, 185-190. 

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