Vicinally unsaturated hydroxy acids in seed oils

Summary The interference of certain unsaturated hydroxy acids in the Durbetaki method of epoxide determination has been demonstrated. The concentrations of these constituents were determined concurrently with those of epoxy components by measurement of the near infrared spectra of samples before and after treatment with anhydrous ethereal hydrogen chloride. The individual hydroxy esters were separated and isolated from samples of mixed esters by thinlayer chromatography. GLC of these esters resulted in their alteration to conjugated trienoates and gave proof of their conjugated diene hydroxyl structure. Thin-layer chromatographic and infrared studies verified theTrans-trans diene unsaturation of the acid fromDimorphotheca aurantiaca oil and showed that the other hydroxy compounds examined have acistrans diene system. These data suggest that the seed oils ofArtemisia absinthium, Calliandra eriophylla, Balanites aegyptica, Cosmos bipinnatus, and Helianthus annuus contain 9-hydroxy-trans-10-cis-12- and 13-hydroxy-cis-9-trans-11-octadecadienoic acids. Supported by grants from The Hormel Foundation and the National Institutes of Health (Research Grant No. H-3559), and presented in part at the 33rd fall meeting, American Oil Chemists’ Society, Los Angeles, Calif., September 28–30, 1959. Fulbright Scholar to the Hormel Institute, 1958–1960.     

Characterization of cyclopropenoid acids in selected seed oils

Evidence is provided that sterculic and malvalic acids occur together in seed oils ofSterculia foetida, Hibiscus syriacus, andLavatera trimestris. Sterculia foetida oil contains 54.5% sterculic and 6.7% malvalic acids;Hibiscus syriacus oil contains 16.3% malvalic and 3.4% sterculic; andLavatera trimestris oil contains 7.7% malvalic and 0.6% sterculic acids.Hibiscus syriacus oil also contains 1.5% dihydrosterculic acid. The cyclopropenoid acids were characterized by hydrogenation in conjunction with gas-liquid chromatography and by oxidation to β-dioxo acids with subsequent cleavage with peracetic acid. Acetolysis of epoxides in the presence of cyclopropenes was effected by room temperature treatment with acetic acid-10% sulfuric acid (5∶2). This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Fatty acids ofLindera umbellata and other Lauraceae seed oils

Seed kernel oils of seven species of Lauraceae were examined and the fatty acid composition of six of these was determined. The oil ofLindera umbellata had 4% ofcis-4-decenoic, 47% ofcis-4-dodecenoic, and 5% ofcis-4-tetradecenoic acid in the total fatty acids. Positive identification of these acids was made and new derivatives were prepared. Possible routes of biosynthesis are discussed. Oils from the other species did not contain more than a trace of unsaturated C₁₀−C₁₄ acids. Their major acids were capric and lauric with varying amounts of unsaturated C₁₈ acids. Issued as NRC No. 8928. Presented at the AOCS Meeting, Cincinnati, October 1965.     

Cyclopropene fatty acids of six seed oils from malvaceae

Seeds ofHibiscus leptocladus, H. sturtii, Sida echinocarpa, Abutilon amplum, Gossypium robinsonii andLagunaria patersonii contained 11.2\s-26.8% oil and 11.6\s-18.2% protein. Spectral, chromatographic and chemical analyses of the seed oils revealed the presence of malvalic (0.5\s-3.2%), sterculic (0.1\s-1.7%) and dihydrosterculic (trace-0.7%) acids.     

Eicosenoic acid and other fatty acids ofSapindaceae seed oils

The seed oils of 11 species ofSapindaceae were examined, and their fatty acid composition was determined.cis-11-Eicosenoic acid was identified as the major fatty acid ofKoelreuteria paniculata. It was present in nine of the 11 species in amounts from 8–60% of the total fatty acids and is evidently a common component of oils of this plant family. Arachidic acid was present in amounts up to 11%. Only three of the oils had acids of chain length greater than C-20. Seed oils of certain species ofKoelreuteria andCardiospermum are good potential sources of 11-eicosenoic acid. N.R. C. No. 9537.     

Cyclopropenoid fatty acids of six seed oils from malvaceae

The seeds ofAlyogine hakeifolia, Alyogine huegelii,Gossypium australe, Hibiscus coatesii, Lawrencia viridigrisea andRadyera farragei (Malvaceae) contained 13.5-18.6% oil. Linoleic acid predominated (60.0-68.2%) in the component fatty acids of all the oils, followed by palmitic (9.9-18.1%) and oleic acids (7.8-15.8%). Cyclopropene fatty acids, malvalic and sterculic, were present in small concentrations (1.0-4.4%, 0.1-1.5% respectively). Dihydrosterculic acid was present in small quantities (trace-2.1%). *To whom correspondence should be addressed at Department of Chemistry, P.O. Box 320, University of Papua New Guinea, Papua, New Guinea.     

Cyclopropenoid fatty acids in seed oils ofurena repanda andthespesia lampas

Seed oils ofUrena repanda andThespesia lampas (Malvaceae) were found to contain malvalic (2.6, 0.6%) and sterculic (1.1, 2.1%) acids, respectively, besides the normal fatty acids. Cooccurrence of these two acids were established by gas Chromatographic analysis of silver nitrate/methanol-treated methyl esters usingSterculia foetida esters as a reference standard.     

cis-5-Monoenoic fatty acids in some chenopodiaceae seed oils

Methyl esters from seed oils of four Chenopodiaceae species are unusual in that they contain methylcis-5-hexadecenoate (4.6–12%) and methyl 5-octadecenoate (1.1–1.2%). There are indications of small amounts of 18∶2^5,9 and 18∶3^{5, 9, 12} along with unsaturated acids commonly found in seed oils-oleic (14–21%), linoleic (53–57%) and linolenic (3.5–7.8%). Fatty acid composition of the oils was determined by gas chromatography, and positions of the double bonds were established by application of gas chromatography-mass spectrometry to the methoxylated methyl esters. N. Market. Nutr. Res. Div., ARS, USDA.     

Determination of cyclopropenoid fatty acids inSterculia seed oils from senegal

Seed oils ofSterculia tomentosa andS. tragacantha (Sterculiaceae) were found to contain malvalic (5.8 and 5.1%), sterculic (11.3 and 30.2%) and dihydrosterculic (0.9 and 0.5%) acids. The total amount of these two cyclopropenoid fatty acids was established by¹H nuclear magnetic resonance and their cooccurrence by gas chromatography. Besides these unusual compounds, the main common fatty acids were palmitic (20 and 24%), oleic (21 and 15%) and linoleic (30 and 16%) acids.     

Cyclopropenoid fatty acids ingnetum scandens and itsterculia pallens seed oils

Seed oils ofGnetum scandens (Gnetaceae) andSterculia pattens (Sterculiaceae) were found to contain sterculic (28.57,6.97) and malvalic (11.27,3.87) acids, respectively. Gas Chromatographic analysis of silver nitrate/meth-anol-treated methyl esters was used to establish the co-occurrence of these two acids.Sterculia foetida methyl esters were used as a reference standard.     

Therans-3-enoic acids ofAster alpinus andArctium minus seed oils

Thetrans-3-enoic acids ofAster alpinus (dwarf aster, rock aster) andArctium minus (burdock) seed oils have been isolated and characterized.Arctium seed oil containstrans-3,cis-9,cis-12-octadecatrienoic acid (9.9%), andAster oil containstrans-3-hexadecenoic (7.1%),rans-3-octadecenoic (1.9%),trans-3,cis-9-octadecadienoic (3.0%),a ndtrans-3,cis-9,cis-12-octadecatrienoic (13.7%) acids.Aster oil also has an epoxy acid as a minor constituent (ca. 2.0%), which has been identified ascis-9,10-epoxy-cis-12-octadecenoic acid.     

A survey of the conjugated fatty acids of seed oils

Fatty acids with conjugated unsaturation occur in many seed oils. Thirty of these acids are reviewed with emphasis on their detection, isolation, and structure determination. Their distribution among plant families is shown, and a botanical source of each acid is given. Some reactions, derivatives, and methods of determining configuration are described. Current theories of their biosynthesis in the seed, involving oxygenated precursors, are summarized.     

Cis-5-monoenoic fatty acids ofCarlina (Compositae) seed oils

Seed oils ofCarlina corymbosa L. andC. acaulis L. containcis-5-octadecenoic acid as a major fatty acid (21–24%). This acid has not been previously reported as a constituent of Compositate seed oils. The predominant fatty acid in theCarlina oils is linoleic (50–52%); lesser amounts (≦10% each) of palmitic, stearic and oleic acids are also present. The oil ofC. acaulis has almost 2% ofcis-5-hexadecenoic acid;C. corymbosa oil includes minor amounts of some oxygenated fatty acids. Presented at the AOCS Meeting, New York, October 1968. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Kamlolenic acid and other conjugated fatty acids in certain seed oils

The major fatty acid of the seed oil ofTrewia nudiflora is shown to be α-kamlolenic acid, not α-eleostearic acid as believed earlier. Other conjugated acids were found and identified in seed oils not previously studied, viz., α-eleostearic acid inParinari insularum andRicinodendron rautanenii; trans,8-trans,10-cis,12-octadecatrienoic acid inCalendula stellata. The identity of the conjugated acids in four other seed oils was established, viz., α-eleostearic acid inPrunus yedoensis andValeriana officinalis; punicic acid inCucurbita digitata andC. palmata. Issued as N.R.C. No. 9063.     

Identity and configuration of conjugated fatty acids in certain seed oils

Punicic acid was found in the seed oils ofCayaponia grandifolia, Trichosanthes cordata andT. cucumerina. α-Eleostearic acid was found inMomordica cochinchinensis, M. cochinchinesis varietymixta andM. cymbalaria. The identity of the conjugated triene acid ofAleurites trisperma, Garcia nutans andCyclandrophora laurina was confirmed as α-eleostearic acid (cis, trans, trans configuration). The configuration of kamlolenic acid was proved to becis-9,trans-11,trans-13. The oils ofAleurites remyi andLicania platypus did not contain any conjugated acid. Issued as N.R.C. No. 10589.     

Analysis of seed oils containing cyclopentenyl fatty acids by combined chromatographic procedures

The fatty acids of seed oils of the Flacourtiaceae,Hydnocarpus anthelmintica, Caloncoba echinata andTaraktogenus kurzii, have been examined by a combination of capillary gas chromatography, silver ion high performance liquid chromatography and gas chromatography-mass spectrometry. In addition to the common range of cyclopentenyl fatty acids found in such oils, 13-cyclopent-2-enyltridec-4-enoic acid was a major component ofH. anthelmintica and was identified by mass spectrometry as its picolinyl ester and dimethyldisulphide adduct. It has not previously been found in nature. In the other seed oils, the isolated double bond in the corresponding fatty acid was in position 6, as expected. Similarly,cis-4-hexadecenoic acid and C₁₆ and C₁₈ cyclopentyl fatty acids were identified for the first time inH. anthelmintica. Iso- andanteiso-methylbranched fatty acids were present in trace amounts.