• Journal of the Korean Applied Science and Technology
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• v.19 no.3
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• pp.222-244
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• 2002

A mixture of methyl ester derivatives of fatty acids from the oils of pine nuts was well resolved to five fractions differing by degree of unsaturation by silver ion solid-phase extraction column chromatography ($Ag^{+}$-SEC). Polyunsaturated fatty acid with non-methylene interrupted conjugated double bond (NMiDB) radical held more strongly to silver ions in the column than methylene interrupted conjugated double bond (MiDB) one when they had the same number of double bonds. Although both the picolinyl ester and DMOX derivative provided clear mass ion species powerful enough to elucidate the structure of the polyunsaturated fatty acid (PUFA) with NMiDB and/or methylene interrupted conjugated double bond (MiDB) radical in the oils, the picolinyl ester of PUFA with NMiDB radical did not provide a cluster of mass ions neighboring diagnostic mass ions induced by the double bond in the proximal to the carboxyl group. However, the DMOX derivative of PUFA with NMiDB group as well as MiDB showed abundant mass ion species differing by gaps of 12 amu, which made it possible with greater ease to locate the double bonds in the molecule. The oil contained $C_{18:2{\omega}6}$ (46.2 %) and $C_{18:1{\omega}9}$ (25.4 %) as main components, and considerable amounts of PUFAs with NMiDB radical such as ${\Delta}^{5.\;9.\;12}-C_{18:3}$ (16.0 %), ${\Delta}^{5.\;9}-C_{18:2}$ (2.3 %) and ${\Delta}^{5.\;11.\;14}-C_{20:3}$ (0.8 %).

• Food Science and Biotechnology
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• v.15 no.1
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• pp.107-111
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• 2006

Kernel oils of Lindera erythrocarpa seeds had high level of unusual fatty acid. Picolinyl ester of this unknown fatty acid showed molecular ion at m/z = 317 with other diagnostic ions such as m/z = 151, 191 (40 amu between two peaks), 204, and 218 on GC-MS. Characteristic peak at $720\;cm^{-1}$ appeared in IR spectrum. In $^1H-NMR$ spectrum both methylene protons at C-3 and C-6 resonated at ${\delta}2.309$ and ${\delta}2.012$, and methine protons of double bond resonated in lower magnetic field centered at ${\delta}5.296$ (C-4) and ${\delta}5.387$ (C-5) as multiplet (J = 9.7Hz). In $^{13}C-NMR$, signals at ${\delta}22.669$ and ${\delta}27.048$ were due to C-3 and C-6 of ${\delta}^4$-monoenoic acid. Results obtained from spectroscopic measurements confirmed unknown fatty acid as cis-4-tetradecenoic acid (cis-4-$C_{14:1}$). Main fatty acid components of oils were cis-4-$C_{14:1}$ (44.5-45.1%), oleic acid ($C_{18:1}$), 20.4-21.3%), and lauric acid ($C_{12:0}$, 11.6-12.4%), along with trace amounts of cis-4-$C_{12:1}$ and cis-4-$C_{16:1}$.

• Journal of the Korean Applied Science and Technology
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• v.22 no.4
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• pp.323-331
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• 2005

Fatty acid compositions of the seed oils of P. schinseng, A. continentalis and A. sessiliflorus, were analyzed by gas chromatography (GC) equipped with a capillary column. A large unusual peak was observed just before the peak corresponding to oleic acid $(cis-9-C_{18:1})$. This unknown fatty acid was isolated by silver ion chromatography and then derivatized into the picolinyl ester. The mass spectrum of the picolinyl ester showed molecular ion at m/z=373 with other diagnostic ions such as m/z=178, 218, 232, 246, 274, 288, 302 and 344. Characteristic absorption peaks at $720\;cm^{-1}$, $1640\;cm^{-1}$ and $3010\;cm^{-1}$ in IR spectrum indicated the presence of cis-configurational double bond in the molecule. The $^1H-NMR$ spectrum of this acid gave two quintets centered at ${\delta}1.638$ (2H, C-3) and ${\delta}1.377$ (2H, C-4), and two multiplets centered at ${\delta}2.022{\sim}2.047$ (2H, C-5) and ${\delta}2.000{\sim}2.022$ (2H, C-8), and multiplet signals of olefinic protons centered at ${\delta}5.3015{\sim}5.3426$ (C-6, J=9.5 Hz) and ${\delta}\;5.3465{\sim}5.3877$ (C-7, J=9.5 Hz). The $^13C-NMR$ spectrum showed 18 carbon resonance signals including an overlapped signal at ${\delta}29.7002$ for C-12 and ${\delta}29.6520$ for C-13 (or they can be reversed), and other highly resolved signals at ${\delta}33.950$, ${\delta}24.558$, ${\delta}26.773$ and ${\delta}27.205$ due to C-2, C-3, C-5 and C-8 of a ${\Delta}^6-octadecenoic$ acid, respectively. From analysis results this unknown fatty acid could be identified as cis-6-octadecenoic acid. The seed oils of P. schinseng and A. sessiliflorus contained petroselinic acid (59.7%, 56.0%), oleic acid (18.3%, 6.1%) and linoleic acid (16.2%, 30.4%) with small amount of palmitic acid (3.0%, 3.1%) while the seed oil of A. continentalis comprised mainly oleic acid (30.2%), petroselinic acid (29.0%), linoleic acid (24.1%) and palmitic acid (13.1%).

• Journal of the Korean Applied Science and Technology
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• v.18 no.1
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• pp.67-77
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• 2001

In search for several fatty acid with unusual structure in vegetable oils, we have found that unknown peaks were shown on GLC in the analysis of fatty acids of the lipids from the pulp of ripened jujube (Zizypus jujuba var. inermis) fruits. These fatty acids were identified as a series of cis-monoenoic acids with ${\omega}-5$ double bond system such as $C_{14:1{\omega}5}$, $C_{16:1{\omega}5}$ and $C_{18:1{\omega}5}$, including ${\omega}-7$ fatty acid as $C_{16:1{\omega}7}$ and $C_{18:1{\omega}7}$, by GLC, solid-phase extraction silver ion-column chromatographic, GLC-mass spectrometric and IR techniques. First of all, total fatty acid methyl esters were resolved into saturated and branched fatty acid, monoenoic acid, dienoic acid, and trienoic acid fraction, respectively, with 100% dichloromethane (DCM), DCM/acetone (9:1, v/v) 100% acetone, and acetone/ acetonitrile (97:3, v/v) solvent system. Unknown fatty acids were included in the monoenoic fraction and were confirmed to have cis-configuration by IR. Picolinyl esters of monoenoic fatty acids gave distinct molecular ion peak and dominant diagnostic peaks, for example, m/z 317, 220 and 260 fragment for $cis-C_{14:1{\omega}5}$, m/z 345, m/z 248 and 288 fragment for $cis-C_{16:1{\omega}5}$ and m/z 373, m/z 276 and 316 fragment for $cis-C_{18:1{\omega}5}$. In this way the occurrence of $cis-C_{16:1{\omega}7}$ and $cis-C_{18:1{\omega}7}$ could be deduced from the appearance of prominent fragments as m/z 345, 220 and 260, and m/z 373, 248 and 280. Level of total ${\omega}-5$ fatty acids amounted to about 30% in the fatty acid composition with the predominance of $C_{16:1{\omega}5}$ $ (18.7{\sim}25.0%)$, in the semi-ripened and/or ripened samples collected in September 14 ($C_{16:1{\omega}5}$ ; 18.7%, $C_{14:1{\omega}5}$ ; 3.6% and $C_{18:1{\omega}5}$ ; 3.0%), September 22 ($C_{16:1{\omega}5}$ ; 25.0%, $C_{14:1{\omega}5}$ ; 1.4% and $C_{18:1{\omega}5}$ ; 2.6%), and October $7 (C_{16:1{\omega}5}$ ; 24.7%, $C_{14:1{\omega}5}$ ; 7.7% and $C_{18:1{\omega}5}$ ; 2.5%). However, the lipids extracted from unripened jujube in July and August contain these unusual fatty acids as low as negligible. It could be observed that the level of ${\omega}-5$ fatty acids in the pulps increased sharply with an elapse of ripening time of jujube fruits. Other monoenoic fatty acids with ${\omega}-7$ series, $C_{16:1{\omega}7}$ (palmitoleic acid) and $C_{18:1{\omega}7}$ (cis-vaccenic acid) could be detected. And in the lipids of the kernel and leaf of jujube, none of ${\omega}-5$ fatty acids could be detected.

• Journal of the Korean Applied Science and Technology
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• v.14 no.1
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• pp.61-76
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• 1997

Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC} in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are $C_{18:2{\omega}6}$(39.0mol%), $C_{18:1{\omega}7}$(asclepic acid 21.5mol%), and $C_{18:1{\omega}9}$(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as $C_{20:3{\Delta}^{5,11,14}$ (5.7mol%), $C_{18:2{\Delta}^{5,9}$(2.8mol%), and $C_{18:3}{\Delta}^{5,9,12}$(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a ${\Delta}^5$-non methylene interrupted double bond($^5$-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a ${\Delta}^5$-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; $(C_{18:2{\omega}6)2}/C_{18:1{\omega}7}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$, $C_{16:1{\omega}7}/C_{18:1{\omega}9}/C_{20:3}{\Delta}^{5,11,14}$, $C_{16:1{\omega}7}/C_{18:1{\omega}7}/C_{20:3}{\Delta}^{5,11,14}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $C_{18:1{\omega}9}/C_{18:2}{\Delta}^{5,5}/C_{20:3}{\Delta}^{5,11,14}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$ and $(C_{18:1{\omega}9)2}/C_{18:2{\omega}6}$, while simple triacylglycerols without $C_{18:2{\omega}6})_3$ were not present. Stereospecific analysis showed that fatty acids with ${\Delta}^5$-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.