The occurrence of ricinoleic acid inLinum seed oils

Thirty-oneLinum species, representing each of the 5 taxonomic sections of the genus, were analyzed for fatty acid composition of the seed oils. Linolenic acid was the major component of the seed oil of species from the sectionsLinum andDasylinum, whereas linoleic acid predominated in those from the sectionsSyllinum, Linastrum andCatbartolinum. All 5 species tested from the sectionSyllinum contained ricinoleic acid as a minor component, ranging between 3% and 8% of total fatty acids. Ricinoleic acid was not present in any other species analyzed. An unidentified fatty acid was present as a minor component in species from the sectionsLinum andDasylinum but absent in species from other sections of the genus.     

Bishomopinolenic (7,11,14–20:3) acid in pinaceae seed oils

Bishomopinolenic (7,11,14–20:3; BHP) acid has been identified in a sample of pine (Pinus contorta) seed oil by gas-liquid chromatography-mass spectrometry of its 4,4-dimethyloxazoline and picolinyl ester derivatives. Neither 20:3n-6 nor 18:3n-6 acids could be detected. The distribution of BHP acid in the seed oils of four conifer families has been established. It only occurred in Pinaceae (Pinus, Abies, Cedrus, Tsuga, Pseudotsuga, Larix, and Picea; 72 species analyzed), where it could reach 0.7% of total fatty acids. It could not be detected in Taxaceae (Taxus baccata), Cupressaceae (Juniperus communis), or Taxodiaceae (Sciadopytis verticillata) seed lipids. It is assumed that BHP acid is the elongation product of pinolenic (5,9,12–18:3) acid, and that, at most, 3% of pinolenic acid is elongated to BHP acid. Consequently, the Δ5-desaturation would not necessarily be a final step in the biosynthesis of unsaturated polymethylene-interrupted fatty acids in Pinaceae seeds. Moreover, conifer seeds appear devoid of the Δ6-desaturase.     

Fatty acid composition ofcuphea seed oils

Nineteen species of 10 taxonomic sections ofCuphea were analyzed for fatty acid composition of the seed oils. Two sections of the genus,Trispermum andPseudocircaea, previously unreported, are included. Lauric acid is the major component of the seed oil in seven of the species surveyed; capric andmyristic each predominate in five. Linolenic acid, previously thought to be only a trace component ofCuphea seed oils, is the major constituent of two species. Two others are rich in linoleic acid, another minor component of mostCupbea oils.     

Epoxy oleic acid inQuamoclit seed oils

Quamoclit phoenicea Choisy andQuamoclit coccinea Moench. (Syn.Ipomoea coccinea Linn), belonging to the Convolvulaceae plant family, was found to contain palmitic (22.2%, 33.3%), stearic (11.3%, 1.7%) oleic (13.5%, 14.6%), linoleic (40.1%, 30.8%), vernolic (6.4%, 10.2%), arachidic (3.5%, 6.8%) and behenic (3.8%, 2.6%) acids, respectively.     

The acetylenic acid inComandra pallida andOsyris alba seed oils

Gas-liquid chromatographic (GLC) analyses are reported for fatty acid methyl esters from seed oils of two previously unreported species of Santalaceae,Comandra pallida A. DC. andOsyris alba L. The major component in each (43 and 57%, respectively) is an enynoic acid, probablytrans-11-octadecen-9-ynoic (ximenynic) acid which has been found in seed oils of other members of this family. Equivalent chain lengths by GLC analysis and infrared and ultraviolet spectra agree with those obtained by our analyses ofXimenia americana L., in which ximenynic acid is known to occur. The spectral data also agree with those in literature reports on ximenynic acid. The positions of unsaturation have, however, not been rigorously established for the two species newly reported. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

γ-Linolenic acid inAcer seed oils

The octadecatrienoic acids inAcer negundo L. (maple family) seed oil include both 9,12,15- (1%) and 6.9,12-(7%) isomers. The chief monoenoic acids identified were 9-octadecenoic (21%), 11-eicosenoic (7%), 13-docosenoic (15%), and 15-tetracosenoic (7%). Also present is a considerable amount of 9,12-octadecadienoic acid. Investigation of ten other Aceraceae revealed their seed oils to have a similar fatty acid composition.     

The fatty acid composition of gymnospermae seed and leaf oils

Of 12 Gymnospermae seed and leaf oils, only 2 contained cyclopropene fatty acids. All-cis 5, 11, 14, 17-eicosatetraenoic acid occurred in concentrations up to 11.9% in 6 seed oils, and up to 61% in 2 leaf oils. The structure of this acid, as its methyl ester, was established by the combination of physical (UV, IR,¹H- and¹³C-NMR and mass spectra) and chemical techniques. Arachidonic acid also occurred in 2 seed oils.     

The occurrence of 6,9,12,15-octadecatetraenoic acid inEchium plantagineum seed oil

The seed oil ofEchium plantagineum, a mem-ber of the borage family, has been shown to contain two polyunsaturated fatty acids not com-monly found in vegetable oils: all-cis-6,9,12-octa-deeatrienoic acid and all-cis-6,9,12,15-octadeca-tetraenoic acid. Prior to their discovery in the Boraginaceae, nonconjugated tetraenoid acids were not known to occur in oils of higher plants. A laboratory of the No. Utiliz. Res. and Dev. Div., ARS, USDA.     

Fatty acid composition in seed oils of some onagraceae

The seeds ofOenothera picensis, O. indecora, Ludwigia longifolia andL. peruviana (Onagraceae) contained 18.3, 16.4, 13.9 and 10.1% oil, respectively. Chromatographic analyses showed high levels of linoleic acid (>71.5%) in the seed oils.     

Fatty acid composition of Iranian citrus seed oils

Fatty acid compositions of seed oils from eight Iranian citrus fruits were determined. The ranges of values for major fatty acids were 21.8–29.4% palmitic, 3.1–7.60% stearic, 0.3–1.3% palmitoleic, 23.5–32.3% oleic, 33.5–39.8% linoleic, and 3.1–7.6% linolenic. Low amounts (up to 0.1%) of myristic and arachidic acids and traces of a few unidentified ones constituted minor fatty acids.     

Fatty acid composition of some pine seed oils

The fatty acid composition of seeds from seven species of the genusPinus (P. pinaster, P. griffithii, P. pinea, P. koraiensis, P. sylvestris, P. mughus, andP. nigra) was established. Pine seeds are rich in oil (31–68% by weight) and contain several unusual polymethylene-interrupted unsaturated fatty acids with acis-5 ethylenic bond. These are thecis-5,cis-9 18:2,cis-5,cis-9,cis-12 18:3,cis-5,cis-11 20:2, andcis-5,cis-11,cis-14 20:3 acids, with a trace ofcis-5,cis-9,cis-12,cis-15 18:4 acid. Their percentage relative to total fatty acids varies from a low of 3.1% (P. pinea) to a high of 30.3% (P. sylvestris), depending on the species. The majorcis-5 double bond-containing acid is generally thecis-5,cis-9,cis-12 18:3 acid (pinolenic acid). In all species, linoleic acid represents approximately one-half the total fatty acids, whereas the content of oleic acid varies in the range 14–36% inversely to the sum of fatty acids containing acis-5 ethylenic bond. The easily available seeds fromP. koraiensis appear to be a good source of pinolenic acid: their oil content isca. 65%, and pinolenic represents about 15% of total fatty acids. These values appear to be rather constant.Pinus pinaster, which is grown on several thousand acres in the southwest of France, is an interesting source ofcis-5,cis-11,cis-14 20:3 acid (7% in the oil, which isca. 35% of the dehulled seed weight), an acid sharing in common three double bonds with arachidonic acid. Apparently,P. sylvestris seed oil contains the highest level ofcis-5 double bond-containing acids among pine seed oils that have ever been analyzed.     

Fatty acid composition of pinaceae as taxonomic markers

Following our previous review on Pinus spp. seed fatty acid (FA) compositions, we recapitulate here the seed FA compositions of Larix (larch), Picea (spruce), and Pseudotsuga (Douglas fir) spp. Numerous seed FA compositions not described earlier are included. Approximately 40% of all Picea taxa and one-third of Larix taxa have been analyzed so far for their seed FA compositions. Qualitatively, the seed FA compositions in the three genera studied here are the same as in Pinus spp., including in particular the same Δ5-olefinic acids. However, they display a considerably lower variability in Larix and Picea spp. than in Pinus spp. An assessment of geographical variations in the seed FA composition of P. abies was made, and intraspecific dissimilarities in this species were found to be of considerably smaller amplitude than interspecific dissimilarities among other Picea species. This observation supports the use of seed FA compositions as chemotaxonomic markers, as they practically do not depend on edaphic or climatic conditions. This also shows that Picea spp. are coherently united as a group by their seed FA compositions. This also holds for Larix spp. Despite a close resemblance between Picea and Larix spp. seed FA compositions, principal component analysis indicates that the minor differences in seed FA compositions between the two genera are sufficient to allow a clear-cut individualization of the two genera. In both cases, the main FA is linoleic acid (slightly less than one-half of total FA), followed by pinolenic (5,9,12-18:3) and oleic acids. A maximum of 34% of total Δ5-olefinic acids is reached in L. sibirica seeds, which appears to be the highest value found in Pinaceae seed FA. This apparent limit is discussed in terms of regio- and stereospecific distribution of Δ5-olefinic acids in seed triacylglycerols. Regarding the single species of Pseudotsuga analyzed so far (P. menziesii), its seed FA composition is quite distinct from that of the other two genera, and in particular, it contains 1.2% of 14-methylhexadecanoic (anteiso-17:0) acid. In the three genera studied here, as well as in most Pinus spp., the C₁₈Δ5-olefinic acids (5,9-18:2 and 5,9,12-18:3 acids) are present in considerably higher amounts than the C₂₀Δ5-olefinic acids (5,11-20:2 and 5,11,14-20:3 acids).     

Fatty acid composition ofThalictrum L. seed oils

The fatty acid composition of five representatives of theThalictrum L. genus of the plant familyRanunculaceae has been investigated. The fatty acids include mainly acids with double bonds in thetrans-5 position (about 60%). Although the main component of the fatty acids is a triene acid (trans-5,cis-9,cis-12-octadecatrienoic acid), the oils investigated are semidrying.     

Analysis and fatty acid composition of tobacco seed oils

Summary THE fatty acid compositions of twelve samples of oil representing a number of different types and varieties of tobacco were determined by the thiocyanometric method. The samples were remarkably uniform in composition, containing on the average 75% linoleic, 15% oleic, and 10% saturated acids. Spectrophotometric determination of the linoleic acid content of two samples of oil gave values 3.0 and 5.4% higher than those by the thiocyanometric method. A more complete investigation of the fatty acid constituents of one sample of flue-cured tobacco seed oil was carried out by analysis of fractions obtained by distillation of the methyl esters and by low-temperature crystallization of the distilled ester fractions. The composition calculated from these analyses agreed well with that determined from analysis directly on the oil. The saturated acids consisted of palmitic and stearic acids, the proportions being about 7 and 3%, respectively, of the total fatty acids. Analysis of this sample of oil showed that it contained 0.043% of tocopherol. From its composition, tobacco seed oil would seem to be particularly suitable for the manufacture of nonyellowing alkyds or for the preparation of technical linoleic acid. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Lipid changes in maturing oil-bearing plants. II. Changes in fatty acid composition of flax and safflower seed oils

Changes in the fatty acids composition of the oil in flax and safflower seed that occur during the seed-ripening period have been measured. Concentrations of lipid or of specific fatty acid, expressed on a weight-per-seed basis, have been plotted as functions of days after fertilization and of percentage of oil development. Relations between these two independent variables have been established, and limitations to the unsefulness of the latter variable have been pointed out. Days after fertilization proved to be the more useful abscissa. Nonpolar solvents were used to remove free lipid from the tissue, and the total extractable matter was separated into true lipid and nonlipid components. With both flax and safflower, weight of true free lipid per seed and total unsaturation increased during the same period of growth. Nonlipid extractable matter was an inverse function of the extent of development. In developing flax seed, oleic, linoleic, and linolenic acids all increased continuously; oil in immature seed however was more saturated than oil in more mature seed. Nevertheless the ratio of linolenic acid to linoleic acid that characterizes linseed oil was established by the 20th day after fertilization during a normal growing season. In developing safflower seed, oleic acid concentration increased slowly during the first 30 days after fertilization and then appeared to level off in some cases as maturity was approached. Initially linoleic acid was present in almost the same amount as oleic acid, but by the 20th day after fertilization its concentration was three times that of oleic acid. This ratio of linoleic to oleic acid tended to increase steadily during the latter part of seed development.     

An unusual fatty acid pattern inEranthis seed oil

The current discussion on “renewable resources”, and the possibility of gene transfer into rapeseed, has led to many investigations into the biosynthetic pathways leading to industrially useful fatty acids. The various tribes and genera of the plant familyRanunculaceae contain a large variety of unusual fatty acids. Seed fatty acid patterns differ considerably from genus to genus and are chemotaxonomically significant indicators.Eranthis seed oil has now been found to contain a fatty acid pattern that deviates significantly from the eleven different fatty acid patterns that had been described in this plant family. The main fatty acid (up to 57%) is 13-cis, 16-cis-docosadienoic acid. Other, minor fatty acids found are Δ5-cis-monoenoic,-dienoic, and-trienoic fatty acids that had already been reported to be constituents of the genus-specific seed oil fatty acid patterns of various genera from this plant family. Capillary gas-liquid chromatographic retention data indicate that 22:3Δ5cis, 13cis, 16cis is probably also present. Seed fatty acid chemotaxonomic evidence thus points to a different position ofEranthis within the tribes of this plant family. These findings again indicate that the plant familyRanunculaceae would be an ideal object to study fatty acid biosynthesis and phylogenetic evolution, because in other genera of this family other types of desaturation and chain elongation mechanisms predominate.     

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.     

Epoxy acid in seed oils ofMalvaceae and preparation of (+)threo-12,13-Dihydroxyoleic acid

Seed oils of six species ofMalvaceae, representing four genera, were found to containcis-12,13-epoxyoleic acid in amounts estimated at 1,5–7% of the total fatty acids. Acetolysis of the oils gave the corresponding dihydroxyoleic acid, which was shown to be predominantly adextro-rotatory form ofthreo-12,13-dihydroxyoleic acid. It was obtained optically pure, and its structure was confirmed by orthodox methods. The hydrogenation product, (+)-threo-12,13-dihydroxystearic acid, was also obtained optically pure and characterized. The best yield of dihydroxyoleic acid was obtained from the seed oil ofMalope trifida. Samples of oil from four other species ofMalvaeae had a very low or negligible content of epoxy acid. Presented in part at the annual meeting, American Oil Chemists’ Society, New Orleans, La., April 20 – 22, 1959. Issued as N.R.C. 6042.     

Occurrence of punicic acid inTrichosanthes bracteata andTrichosanthes nervifolia seed oils

The seeds ofTrichosanthes bracteata andTrichosanthes nervifolia (Cucurbitaceae) contained 31.6 and 27.9% oil and 18.8 and 16.7% protein, respectively. Spectral, chromatographic and chemical analyses showed the punicic acid to occur to an extent of 41.8% inT. bracteata and 51.7% inT. nervifolia seed oils.