Vemolate

The encapsulation of herbicides has received much attention. Encapsulated alachlor is a high volume herbicide product generally sold as a Hquid formulation, although a dry granule version is also available. The capsules, produced by interfacial polymeri2ation (11), are reported to be spherical with a diameter of 2—15 p.m (75). Two thiocarbamate herbicides, EPTC and vemolate [1929-77-7], were encapsulated by interfacial polymeri2ation because they are volatile compounds. When appHed in unencapsulated form, they must be incorporated in the soil within two hours in order to provide effective weed control. When appHed as a microencapsulated formulation, the rate of volatili2ation is lower and soil incorporation can be delayed 24 hours (76). 

Vemolate [1929-77-7] Cyprldopsls vidua EC5o(48-h) -0.60 Johnson and Finley, 1980... 

One species of Euphorbia in Brazil (Bernardia pulchelld) has been determined to contain more than 90% vemolic acid in the triglyceride [120]. This level of single-component purity is equivalent to the level of ricinoleic acid typically found in castor oil. These different varieties of epoxidized oil plants will probably continue to be the subject of agricultural development in the coming years. 

A number of naturally-occurring fatty acid epoxides have been isolated from various sources. Among these are cw-O.lO-epoxyoctede-ranoie acid,17 cw-9,10-opoxyoctadec-li-enoic (coronaric) acid,laM cis-12,13-epoxy oetadec-8-enoio (vemolic) acid,10 - 77 and cie-16,16-i- poxyoctadeca9,12-dienoic acid 878... 

Thiocarbamates Butylate, Cycloate, Diallate, EPTC, Molinate, Pebulate, Trillate, Vemolate... 

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). 

Di-n-propylamine CDAA, EPTC, isopropalin, nitralin, oryzalin, prodiamine, propalin, prosulfocarb, trifluralin, vemolate... 

These are average values from recent years crops bContains 89.2% ricinoleic and 1.4% dihydroxystearic acids Contains 59.8% crepenynic acid "Contains 78.0% licanic acid and 4.0% hydroxy acids eHigh-erucic-acid variety Contains 71.3% vemolic acid 6Contains 78.5% vemolic acid and 5.8% hydroxy fatty acids. 

Vemolic acid (or c -12,13-epoxy-octadec-cA-9-enoic acid) (Fig. 6) was the hrst naturally occurring epoxy fatty acid isolated from the seed oil of Vernonia anthelmintica. It is also found in several Compositae, Malvaceae, and Euphorbiaceae species in signihcant amounts. Other epoxy acids include... 

The list of natural fatty acids exceeds 1000, but commercial interest is limited to a smaller number— perhaps around 20. Ignoring the lipid membrane, rich in ot-lino-lenic acid and present in all green tissue, the three dominant acids in the plant kingdom are palmitic, oleic, and linoleic, sometimes accompanied by stearic acid and by linolenic acid. Others, occuring in specialty oils, include myristic, lauric, erucic, hexadecenoic, petroselinic, y-linolenic acid, eleostearic and isomers, ricinoleic, and vemolic (Table 1). 

Some contain vemolic acid (12,13-epoxyoleic acid). This has several potentially useful properties, and attempts are being made to produce an economically viable crop. 

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. 

Conacher and Gunstone reported the novel conversion of the diene monoepoxide methyl vemolate (187 equation 78) to the cyclopropyl keto isomer (188). Later Italian work supported this conclusion, and furnished additional examples of cyclopropane formation. 

Fission-rearrangement of epoxides. Following his suggestion that epoxy-acids may be important intermediates in biosynthesis,19 Gunstone with Conacher 20 found that when the unsaturated epoxy ester methyl vemolate (1) is treated with boron trifluoride etherate in cold benzene solution it is converted into a number of products, two of which cannot be separated from each other but, together, account for a yield of 34%. On the basis of chemical properties, infrared, NMR, and mass spectra they are believed to be the cis and trans forms of the ketocyclopropane ester (2). 

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