The Separation and Structure Determination of an Eicosatrienoic and an Eicosadienoic Acid in Nagi Seed Oil

Dareville

Martin

1997

J Americ Oil Chem Soc

Triacylglycerols (TAG) were purified from the storage lipids extracted from the seeds of several conifer species (Taxus baccata, Larix decidua, Sciadopytis verticillata, and Juniperus communis), each species belonging to one of the four families Taxaceae, Pinaceae, Taxodiaceae, and Cupressaceae, respectively. Each species was characterized by a high content of 5, 9-18:2, 5,9,12-18:3, 5,11,14-20:3, or 5,11,14,17-20:4 acids, respectively. TAG were partially deacylated with ethylmagnesium bromide, and the resulting 1,2-, 2,3-diacylglycerols (DAG), and 2-monoacylglycerols (MAG) were purified by thinlayer chromatography. 1,2-and 2,3-DAG were further fractionated by chiral column high-performance liquid chromatography of the 3,5-dinitrophenylurethane derivatives. Alternately, TAG were subjected to porcine pancreatic lipase, and the resulting 2-MAG were purified for further analysis. Gas-liquid chromatography of fatty acid methyl esters prepared from the separated DAG and MAG, coupled with appropriate calculations, indicated that the ∆5-olefinic acids, irrespective of the species, chainlengths and number of ethylenic bonds, were considerably enriched in the sn-3 position of TAG where they accounted for ca. 35 to 74 mole% of fatty acids esterified to this position (depending on the initial level of total ∆5-olefinic acids in TAG), which corresponded to 79-94% of ∆5-olefinic acids esterified to the three positions. On the other hand, ∆5-olefinic acids were less than 10% in the sn-2 position and less than 6% in the sn-1 position of TAG. This specific enrichment of ∆5olefinic acids in the sn-3 position thus appears to be a general characteristic of conifer seed TAG. These results were extended to TAG from the seeds of two pine species (Pinus koraiensis and P. pinaster) that are rich in ∆5-olefinic acids and available commercially on a ton-scale. JAOCS 74, 515-523 (1997).

Section: Resultsmentioning

confidence: 93%

Positional distribution of Δ5‐olefinic acids in triacylglycerols from conifer seed oils: General and specific enrichment in the sn‐3 position

Dareville

Martin

1997

J Americ Oil Chem Soc

“…Podocarpus species are also characterized by exceptionally high levels of 11,14-20:2 acid, in the range of 6 to 12%. The particular abundance of 11,14-20:2 and 5,11,14-20:3 acids in P. nagi seed oil was first recognized by Ito et al (17) and Takagi (18), who established their structures by chemical means. Later, Takagi and Itabashi (8) confirmed this characteristic by capillary GLC, and our results are in good agreement with data from the latter authors.…”

Section: Resultsmentioning

confidence: 99%

The seed fatty acid composition and the distribution of Δ5‐olefinic acids in the triacylglycerols of some taxares (Cephalotaxus and Podocarpus)

Pédrono

Marpeau³

et al. 1999

J Americ Oil Chem Soc

The fatty acid compositions of the seeds from four Cephalotaxus species or varieties (plum yews; Cephalotaxaceae) and two Podocarpus species (podocarps; Podocarpaceae) have been established. These compositions were compared with those previously published for some Taxaceae species (Taxus and Torreya). Cephalotaxaceae, Podocarpaceae, and Taxaceae belong to the Taxares suborder. ∆5-Olefinic acids are present in the seed lipids from all species analyzed. In Cephalotaxus, Podocarpus, and Torreya, the prominent ∆5-olefinic acid that occurs is the trienoic acid 5,11,14-20:3 (sciadonic) acid, comprising from 6.7 to 26.4% of total fatty acids. In these species, the ∆5,11 structure is largely favored over the ∆5,9 structure: the 5,9-18:2 (taxoleic) and 5,9,12-18:3 (pinolenic) acids are at the limit of detection, in contrast to Taxus and most Pinaceae species, where these two ∆5-olefinic acids generally predominate. 14-Methylhexadecanoic acid, an habitual though minor component of Pinaceae and Ginkgo biloba seed lipids, could not be detected in Cephalotaxus species studied here and was tentatively identified in trace amounts only in one Podocarpus species. In addition to sciadonic acid, Cephalotaxus and Podocarpus seeds are characterized by unusually high amounts of 11,14-20:2 acid, in the range of 3.1-12.0%. This contrasts with most of the 170 species of conifers analyzed so far (from the families Pinaceae, Cupressaceae, Taxodiaceae, Taxaceae, and Sciadopityaceae, which belong to the Pinares suborder), where this acid is generally ≤2%. A close resemblance between Torreya grandis and three of the Cephalotaxus species analyzed might be indicative of some phyletic relationship between the families Cephalotaxaceae and Taxaceae. 13 C nuclear magnetic resonance spectroscopy of the seed oils from C. drupaceae and P. andinus has shown that ∆5olefinic acids are apparently excluded from the internal position of triacylglycerols, which is a characteristic common to all Coniferales species analyzed so far, and consequently of great antiquity.Paper no. J8951 in JAOCS 76, 469-473 (April 1999).

“…These are the 5,9-18:2 (taxoleic), 5,9,12-18:3 (pinolenic), 5,9,12,15-18:4, 5,11-20:2, 5,11,14-20:3 (sciadonic), and 5,11,14,17-20:4 (juniperonic) acids (all double bonds in the cis configuration). The structures of these fatty acids have been unambiguously established by several analytical procedures, including capillary gas-liquid chromatography on several different stationary phases and comparison with related authentic standards (Wolff and Bayard 1995;Wolff et al 1996), 13 C and 1 H nuclear magnetic resonance spectroscopy (Takagi and Itabashi 1982;Gunstone et al 1995;Gunstone and Wolff 1996), mass spectrometry of appropriate derivatives (Plattner et al 1975;Takagi and Itabashi 1982;Lie Ken Jie et al 1991;Berdeaux and Wolff 1996), and chemical degradation (Ito et al 1963;Hansen and Meiklen 1969;Plattner et al 1975). Incidentally, some D5-olefinic acids from conifer seeds have been shown to favorably alter several lipid variables in the rat.…”

Section: Introductionmentioning

confidence: 99%

Chemotaxonomic differentiation of conifer families and genera based on the seed oil fatty acid compositions: multivariate analyses

Deluc

Marpeau

1997

Trees