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The reaction of methyl 11,12-E-epoxy-9Z-octadecenoate (1) with boron trifluoride etherate furnished a mixture of methyl 12-oxo-10E-octadecenoate (3a) and methyl 11-oxo-9E-octadecenoate (3b) in 66% yield. Methyl 9,10-Z-epoxy-11E-octadecenoate (2) with boron trifluoride etherate furnished a mixture of methyl 9-oxo-10E-octadecenoate (4a, 45%) and methyl 10-oxo-11E-octadecenoate (4b, 19%). A plausible mechanism is proposed for these reactions, which involves the attack on the epoxy ring system by BF3, followed by deprotonation, oxo formation, and double bond migration to give a mixture of two positional alpha,beta-unsaturated C18 enone ester derivatives (3a/3b, 4a/4b). The structures of these C18 enone ester derivatives (3a/3b, 4a/4b) were identified by a combination of NMR spectroscopic and mass spectrometric analyses.

The first successful preparation of phosphorus-containing heterocyclic fatty acid derivatives is described. Reaction of the C18 α-keto allene 1 and the C18 α-keto chloroallene 2 with trimethyl phosphite gave the 1,2-oxaphospholene derivatives 4 and 6, respectively. Hydrolysis of 4 and 6 furnished the corresponding alkenyl phosphonate 5 and alkenyl chlorophosphonate 7, respectively. α-Chloro-α′-keto allene 3 gave the oxaphospholene derivative 8. The various intermediates and products were identified by a combination of spectroscopic and spectrometric techniques. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Epoxidation of methyl (92,11E)-octadecadienoate (1) with various epoxidizing agents viz. m-chloroperoxybenzoic acid, dimethyl dioxirane, methyltrioxorhenium/hydrogen peroxide, potassium peroxomonosulfate (Oxone, 2KHSO 5 . KHSO 4 . K 2 SO 4 )/tetrahydrothiopyran-4-one, and Novozyme 435/hydrogen peroxide is described. The reactions furnished the corresponding mono-epoxy [methyl (11,12E)-epoxy-(9Z)-octadecenoate (2) and methyl (9,10Z)-epoxy-(11E)-octadecenoate (3)] and a mixture of diastereomers of syn- and anti-diepoxy-stearate [methyl (9,10Z;11,12E)-diepoxystearate (4a-4d)], which were identified by a combination of spectroscopic and spectrometric analyses.

Computer technology has provided chemical research with many new and advanced analytical techniques. By the year 2050 computers are predicted to run a million times faster than today's machines. Scientists have remained satisfied with their studies of molecules and to dwell in the dimensions of space and matter only. The difficulty for humans to comprehend the 'idea of time' has kept the issue of time on the sideline. The human brain is an infinitely more powerful and intelligent computer than our silicon chip driven computers. For the brain to be intelligent, the 'idea of time' appears to play an important role. With the large amount of lipid molecules found in the brain, lipidologists are in a position to unravel this mystery of life. The development of robotics, nanotechnology and genetic engineering depends on the continued growth of computing power. Quantum computers are new concepts and there is a chance for lipidologists to mimic the brain and produce an intelligent computer system, which runs on fat molecules (FAT' chips). Imagination is the mother of invention. One of the latest advances in fatty acid chemistry is the study of lipid molecules containing a [60]fullerene unit. Such futuristic molecules are viewed as potential drugs, as well as potential components for the design of the FAT' chip. The future direction of the fat, nutrition and oleochemical industry rests on demands from the consumers. By the year 2050, the average life span for men and women in the industrial countries will increase significantly to 80 for women and 75 for men. A great demand for geriatric gourmet food, nutraceuticals, cosmetics and body-care products is to be expected. With the birth rate declining in these countries, there will also be a great demand for special infant food products - especially, mother's milk. La technologie informatique a fourni a la recherche chimique des techniques analytiques nouvelles et avancees. La spectroscopie RMN et la spectrometrie de masse sont devenues des outils analytiques performants et sophistiques. Les chimistes ont concentre leurs efforts sur les effets des structures a 3 dimensions et envisagent maintenant de considerer la quatrieme dimension: le temps. L'une des dernieres avancees technologiques est l'etude des molecules lipidiques contenant une unite [60]fullerene. Le developpement de la chimie sera, dans les 50 prochaines annees, liee a l'evolution de la population, notamment en s'orientant vers les produits destines aux vieillards.

Some 1,2- and 1,3-diacyl glycerols (with acyl groups as stearyl, oleyl, linoleyl, or stearolyl) were synthesized by conventional methods. The diacyl glycerols were esterified with 6-bromo-hexanoic acid to give the corresponding bromotriacylglycerols (of the type AAB and ABA containing a bromo group at the distal part of the hexanoate chain). The bromo function was transformed to an azide group by reaction of the bromotriacylglycerols with sodium azide. The resulting azido-triacylglycerols were then reacted with [60]fullerence to give the requisite aza-fullerenoid triacylglycerol of the type ABA or AAB (45–62% yield based on the amount of [60]fullerence reacted). The nitrogen atom attached to the carbon cage formed a “[5,6]-open” type aza substructure, which was confirmed by the appearance of 31–32 signals in the region of δC 133–148 (carbon shifts of sp 2 carbons of the cage) in the 13C nuclear magnetic resonance spectra. The spectroscopic and mass spectrometric properties of these novel fullerenoid triacylglycerols are reported.

Reactions of methyl 6-azido-hexanoate, 8-azido-octanoate, and 12-azido-dodecanoate with [60]fullerene (1) gave the corresponding aza-[60]fullerene ester derivatives (2a-2c, 22–35% based on the amount of [60]fullerene reacted). The nitrogen atom is bonded to the [60]fullerene cage to yield a “[5,6]-open” type aza substructure. This was confirmed by the appearance of 30–31 sp2 signals at δC 133–147 in the carbon nuclear magnetic resonance spectra. Reaction of methyl 11-azido-7-undecynoate with [60]fullerene furnished a mixture of aza-[60]fullerene (2d, 53%) and aziridine-[60]fullerene (2e, 38%) ester derivatives. Compound 2e was identified as the “[6,6]-closed” type aziridine-[60]fullerene derivative, which displayed 10 sp2 signals in the region δC 140–145 and one signal at δC 85.05 for the sp3 carbons of the cage. Refluxing a solution of compound 2d in toluene for 50 h gave about 50% yield of compound 2e, but not vice versa.

Primary amines (ammonia, methyl, propyl, octyl, octadecyl, phenyl, benzyl, phenethyl) including methyl esters of amino acids (glycine, DL-alanine, L-valine, L-leucine, L-tyrosine, and L-methionine), and secondary amines (dimethyl, diethyl, dipropyl, diisopropyl, dioctyl, and diphenyl) attack regiospecifically the central carbon atom of the allene system of methyl 12-keto-9,10-octadecadienoate (1) to give the corresponding lipidic enaminone derivatives (2-21) with an average yield of 77%. The E- and Z-configuration of the enaminone system of these novel lipid derivatives was confirmed by infrared and nuclear magnetic resonance spectroscopic techniques. Primary amines furnished Z-enaminones, while secondary amines gave E-enaminones.

Lewis acid-induced carbocationic addition reactions to methyl santalbate [methyl (E)-octadec-11-en-9-ynoate] [(E)-1] give products by regioselective formation of a new carbon−carbon bond at C-9 of the molecule chain. The allenic fatty acid derivatives methyl 12-chloro-9-(1-oxoheptyl)-9,10-octadecadienoate (2) and methyl 9-isopropyl-9,10-octadecadienoate (3) were obtained by Friedel−Crafts acylation of 1 with heptanoyl chloride and alkylation of 1 with isopropyl chloroformate, respectively. While the reaction between 1 and formaldehyde induced by Me2AlCl or Et3Al2Cl3 gives a mixture of the conjugated chlorodienes 5a and 5b, the corresponding reaction carried out in the presence of AlCl3 affords the α,β-unsaturated ketone 6.

Tris(hydroxymethyl)aminomethane was successfully esterified with saturated and unsaturated long-chain fatty acids. The resulting amino-triester intermediates were successively reacted with chloroacetyl chloride, sodium azide, and C60 fullerene. Spectral evidence showed that the aziridine ring is joined to the junction of 16,6]-fused rings of the fullerene. The structures of the various C60 fullerene derivatives bearing a long-chain saturated or unsaturated triester system were characterized by spectroscopic and spectrometric methods.

A conjugated C18 keto-allene ester was prepared starting from methyl ricinoleate (the main component of castor oil). Bromination-dehydrobromination of methyl ricinoleate gave methyl 12-hydroxy-9-octadecynoate. Chromic acid oxidation of the latter gave methyl 12-oxo-9-octadecynoate, which was isomerized with aqueous NaHCO3 to yield a conjugated C18 keto-allene ester (methyl 12-oxo-9,10-octadecadienoate). The latter compound was reacted with hydrazine, methyl hydrazine and phenyl hydrazine in methanol under concomitant ultrasonic irradiation to give methyl 9-[3(5)-hexyl-1H-pyrazol-5(3)-yl]-nonanoate (3, 83% yield), methyl 9-[5-hexyl-1-N-methyl-pyrazol-3-yl]-nonanoate (4, 52%) and methyl 9-[5-hexyl-1-N-phenyl-pyrazol-3-yl]-nonanoate (5, 86%), respectively. The study revealed that the nucleophilic attack of the keto-allenic substrate was initiated by the less hindered (less substituted) nitrogen of the hydrazine reagent, which attacked the central atom of the keto-allene system. A subsequent attack of the carbonyl carbon atom by the remaining nitrogen of the hydrazine was followed by the elimination of a molecule of water to give the pyrazole nucleus. The structures of the pyrazole products (3–5), including that of the key C18 keto-allene substrate (2), were identified by infrared, NMR spectroscopy and mass spectrometry.

Five fatty ester derivatives of podophyllotoxin have been prepared by reacting the corresponding fatty acids with the hydroxy group of podophyllotoxin in the presence of dimethylaminopyridine and N,N-dicyclohexylcarbodiimide. The fatty acids incorporated are: 9,12-epoxy-9,11-octadecadienoic acid, octadec-11E-en-9-ynoic acid, 11,12-E-epoxy-octadec-9-ynoic acid, octadeca-9Z,11E-dienoic acid and 9,10-dibromooctadecanoic acid. The average yield of esterification was >95% and the structures of the products were confirmed by a combination of nuclear magnetic resonance spectroscopic and mass spectrometric analyses.

Reduction of methyl 8-hydroxy-11-E/Z-octadecen-9-ynoate (1) with zinc in either aqueous n-propanol or water under concomitant ultrasound irradiation furnished a mixture of methyl 8-hydroxy-9Z,11E-octadecadienoate (3a) and methyl 8-hydroxy-9Z, 11Z-octadecadienoate (3b) (96% yield). Reduction of methyl 8-oxo-11-E/Z-octadecen-9-ynoate (2) under similar conditions gave methyl 8-oxo-10-Z-octadecenoate exclusively (4, 70%). The latter compound was epoxidized and converted to a C18 furanoid fatty ester (6, methyl 8,11-epoxy-8,10-octadecadienoate) in 70% yield.

The esterification of five medium- and long-chain acetylenic alcohols (2-nonyn-1-ol, 10-undecyn-1-ol, 6-octadecyn-1-ol, 9-octadecyn-1-ol, and 13-docosyn-1-ol), seven olefinic alcohols (cis-3-nonen-1-ol, 10-undecen-1-ol, cis-6-octadecen-1-ol, cis-9-octadecen-1-ol, trans-9-octadecen-1-ol, trans-9, trans-11-octadecadien-1-ol, cis-9,cis-12-octadecadien-1-ol), and four short-chain unsaturated alcohols (allyl alcohol, 3-butyn-1-ol, 3-pentyn-1-ol, and cis-2-penten-1-ol) with pentanoic or stearic acid in the presence of various lipase preparations was studied. With the exception of 2-nonyn-1-ol, where Lipase AY-30 (Candida rugosa) was used as the biocatalyst, the esterification of C11, C18, and C22 acetylenic alcohols with pentanoic acid appeared to be generally unaffected by the presence of an acetylenic bond in the alcohol as relatively high yields of the corresponding esters (78-97%) were obtained. However, medium- and long-chain olefinic alcohols were discriminated by Lipase AY-30, Lipolase 100T (Rhizomucor miehei), and especially by porcine pancreatic lipase (PPL), when esterification was conducted with pentanoic acid. Esterification of medium- and long-chain acetylenic or olefinic alcohols with a long-chain fatty acid, stearic acid, was very efficient except when Lipase AY-30 and Lipolase 100T were used. Short-chain unsaturated alcohols were much more readily discriminated. 3-Pentyn-1-ol and 3-butyn-1-ol were difficult (

Epoxidation of the double bond in methyl oleate, octadec-11E-en-9-ynoate, ricinoleate (12-hydroxy-octadec-9Z-enoate), iso-ricinoleate (9-hydroxy-octadec-12Z-enoate), and 12-oxo-octadec-9Z-enoate with potassium peroxomonosulfate (oxone, 2 KHSO5.KHSO4.K2SO4) in the presence of trifluoroacetone or methyl pyruvate gave the corresponding monoepoxy derivatives. Reaction of Oxone with methyl linoleate and octadeca-9Z,11E-dienoate furnished the corresponding diepoxystearate derivative. Methyl 9,12-dioxo-octadec-10Z-enoate was obtained when a C18 furanoid fatty ester (methyl 9,12-epoxy-9,11-octadecadienoate) was treated with Oxone. The yield of these reactions was very high (85-99%), and the epoxy derivatives were readily isolated by solvent extraction. The products were identified by spectroscopic methods.

The corresponding 1,2,3-triazole derivatives were readily obtained when activated acetylenic fatty acid esters, viz. methyl 2-undecynoate (1), 14-oxo-12-octadecynoates (3), 12-oxo-10-octadecynoate (5), 8-oxo-11(E/Z)-octadecen-9-ynoate (7), 8-oxo-11,12-epoxy-9-octadecynoate (9), were reacted with sodium azide in dimethylformamide. An α-epoxy group to the acetylenic function was also found to be activating the triazolation process. Thus, methyl 11,12-epoxy-9-octadecynoate (11) reacted with sodium azide under reflux in ethanol in the presence of ammonium chloride to give a regiospecific derivative, namely 4-(1-azido-2-hydroxy-octyl)-5-(7-carbomethoxyheptyl)-1,2,3-triazole (12). The structure of the various derivatives were characterized by a combination of infrared, nuclear magnetic resonance spectroscopic and mass spectrometric analyses.

Dehydrobromination of dibromo derivatives of olefinic fatty acids was accomplished using KOH in 20% aqueous ethanol under concomitant ultrasonic irradiation (20 kHz) for 30 min at ambient temperature to give the corresponding acetylenic fatty acid derivatives (52–72% yield). Ten different dibromo fatty acid substrates were used. Products include: fatty acids with a terminal or internal acetylenic bond; acetylenic fatty acids containing an additional functional group, such as hydroxy, chloro or azide group. The structures of the products were characterized by infrared and NMR spectroscopy.

During the past two decades, nuclear magnetic resonance spectroscopy (NMR) has played an ever-increasing role in the structural determination of fatty acids, fatty acid derivatives and analogues, and in the analysis of the structures of triacylglycerols including the quantitative analysis of lipid mixtures. This article discusses some of the results obtained through the application of the NMR technique to lipid molecules and reviews the literature. To maintain brevity, this article does not cover the underlying theory of NMR spectroscopy as numerous books devoted to modern NMR spectroscopy have been published.

Reaction of methyl undec-10-ynoate (1) with selenium dioxide/tert-butyl hydroperoxide (TBHP) in aqueous dioxane gave methyl 9-oxo-undec-10-ynoate (2, 9%) and 9-hydroxy-undec-10-ynoate (3, 60%), while methyl octadec-9-ynoate (4) yielded mixtures of positional isomers of mono-keto (viz. methyl 8-oxo- and 11-oxo-octadec-9-ynoate, 5, 5%), hydroxy-keto (viz. methyl 8-hydroxy-11-oxo- and 11-hydroxy-8-oxo-octadec-9-ynoate, 6, 10%), and dihydroxy (viz. methyl 8,11-dihydroxy-octadec-9-ynoate, 7, 24%) derivatives. Similar treatment of a conjugated diacetylenic fatty ester (methyl octadeca-6,8-diynoate, 8) furnished a mixture of methyl 5-oxo- and 10-oxo-octadeca-6,8-diynoate (9, 12%) and a complex mixture of very polar products. Reaction of methyl octadec-11E-en-9-ynoate (methyl santalbate) (10) with selenium dioxide/TBHP in aqueous dioxane gave exclusively a mixture of regiospecific products, viz. methyl 8-oxo-octadec-11(E)Z-en-9-ynoate (11, 6%) and methyl 8-hydroxy-octadec-11E-en-9-ynoate (12, 70%). The structures of the various products were determined by a combination of spectroscopic and mass spectral analyses.

Five positional isomers of acetylenic tellura stearate (1–5) have been synthesized by three different routes. The number of methylene groups located between the acetylenic system and the tellurium metal varies from 0 to 4. The 1H and 13C NMR spectroscopic properties have been studied. The tellurium atom induces strong deshielding effects on the adjacent methylene protons, which in combination with the deshielding effects of the acetylenic system allows most of the methylene groups between the tellurium and the triple bond to be identified by 1H NMR spectroscopic analysis. The tellurium causes a very strong shielding effect (ca. −27.1 ppm) on the carbon shift of the adjacent α-methylene carbon atom, but weak deshielding effects on the β-(ca. +2.6 ppm) and γ-(ca. +2.3 ppm) methylene carbon atoms. Carbon shifts of methylene carbon atoms, especially those which are located between the tellurium atom and the triple bond, are found very much upfield (δC 0.65–4.81) and in one case in the negative region (δC−17.95) of the 13C NMR spectrum. Most of the signals of the carbon nuclei of these analogue have been identified and from the results of these analyses the number of methylene groups between the acetylenic system and the tellurium atom can be determined.

Oxidative ring opening reaction of methyl 9,12-epoxy-9,11-octadecadienoate (1) with excess magnesium monoperoxyphthalate (MMPP) under ultrasonic irradiation in water furnished methyl 9,12-dioxo-cis-10-octadecenoate (2, 93%). Reaction of compound 1 with 10 molar equivalents of m-chloroperoxybenzoic acid (m-CPBA) in dichloromethane gave methyl cis-10,11-epoxy-9,12-dioxooctadecanoate (3, 91.5%) exclusively. Under ultrasonic irradiation, compound 1 reacted with m-CPBA to give a mixture of compounds 2 (60%) and 3 (40%). Isomerization of methyl 9,12-dioxo-cis-10-octadecenoate (2) to the corresponding trans-isomer (methyl 9,12-dioxo-trans-10-octadecenoate, 4, 95%) was achieved in the presence of pyridine in water under ultrasonic irradiation. Compound 4, alternatively prepared in 95% yield from compound 1 by reaction with pyridinium chlorochromate, was readily epoxidized with hydrogen peroxide to methyl trans-10,11-epoxy-9,12-dioxooctadecanoate (5, 95%). The corresponding cis-isomer (methyl 9,12-dioxo-cis-10-octadecenoate, 2) resisted all attempts by MMPP and hydrogen peroxide to be epoxidized. The structures of the various derivatives (2–5) of compound 1 were identified by a combination of spectroscopic techniques including IR, 1H- and 13C-NMR spectroscopy.

Raman spectra (300–1200 cm−1) have been recorded for all the positional isomers of the selena (X=Se), sulphinyl (X=SO) and sulphonyl (X=SO2) methyl laurates CH3(CH2)nX(CH2)mCO2CH3, (n+m =9). The Raman spectra of two isomers of the tellura series (X=Te) were also obtained as were the IR spectra of the sulphonyl series. The SeC2 and TeC2 moieties each give two characteristic Raman bands at 564 and 651 cm−1 and 510 and 600 cm−1 respectively. The SO group gives a characteristic Raman band at 1016 cm−1. The symmetric stretching and bending modes of the SO2 group can be observed in both the IR and Raman spectra at 1109 and 517 cm−1 respectively. These quoted values do change when the functional group is near the carbonyl group or towards the end of the alkyl chain

Methyl ricinoleate (1) was treated with bromine and the dibromo derivative (2) was reacted with ethanolic KOH under ultrasonic irradiation to give 12-hydroxy-octadec-9-ynoic acid upon acidification with dil. HCI. The latter compound was methylated with BF3/methanol to give methyl 12-hydroxy-octadec-9-ynoate (3). Compound 3 was treated with methanesulfonyl chloride in the presence of triethylamine in CH2Cl2 to give methyl 12-mesyloxy-octadec-9-ynoate (4). Reaction of methyl 12-mesyloxy-octadec-9-ynoate with aqueous KOH under ultrasonic irradiation (20 kHz) gave (11E)-octadecen-9-ynoic acid (5, santalbic acid, 40%) and (11Z)-octadecen-9-ynoic acid (6, 60%) on acidification with dil. HCI. These isomers were separated by urea fractionation. The 13C nuclear magnetic resonance (NMR) spectroscopic properties of the methyl ester and the triacylglycerol (TAG) esters of these enynoic fatty acid isomers were studied. The carbon shifts of the unsaturated carbon nuclei of the methyl ester of the E-isomer were unambiguously assigned as 88.547 (C-9), 79.287 (C-10), 109.760 (C-11), and 143.450 (C-12) ppm, while the unsaturated carbon shifts of the (Z)-enynoate isomer appeared at 94.277 (C-9), 77.561 (C-10), 109.297 (C-11), and 142.668 (C-12) ppm. In the 13C NMR spectral analysis of the TAG molecules of type AAA containing either the (Z)- or (E)-enyne fatty acid, the C-1 to C-6 carbon atoms on the alpha- and beta-acyl positions were differentiated. The unsaturated carbon atoms in the alpha- and beta-acyl chains were also resolved into two signals except that of the C-11 olefinic carbon. Sandal (Santalum album) wood seed oil (a source of santalbic acid) was separated by silica chromatography into three fractions. The least polar fraction (7.2 wt%) contained TAG which had a random distribution of saturated and unsaturated fatty acids, of which oleic acid (69%) was the predominant component. The second fraction (3.8 wt%) contained santalbic acid (58%) and oleic acid (28%) together with some other normal fatty acids. Santalbic acid in this fraction was found in both the alpha- and beta-acyl positions of the glycerol "backbone." The most polar fraction (89 wt%) consisted of TAG containing santalbic acid only. The distribution of the various fatty acids on the glycerol "backbone" was supported by the results from the 13C NMR spectroscopic analysis.

The triacylglycerol fraction of three samples of margarine, namely “Flora” (Holland), “Kaliakra” (Bulgaria), and “Corona” (Holland), were studied by13C nuclear magnetic resonance spectroscopy. By examining the various carbon chemical shifts of the saturated and unsaturated carbon nuclei, “Flora” margarine was shown to contain a mixture of hydrogenated and unhydrogenated vegetable oils. This technique allowed all major acyl groups (saturated, oleate, linoleate, and linolenate) and minor acyl components [different positional isomers of long-chain (E)- and (Z)-monoenoic moieties, arising as by-products during catalytic hydrogenation] to be identified. The amount of each fatty acid present in the margarine was also estimated from the relative intensities of the corresponding signals. “Kaliakra” margarine consisted of a blend of unhydrogenated natural fats and oils that contained saturated fatty acids, oleate, and linoleate. There were no signs in the spectrum of “Kaliakra” of any (E)-isomers, nor signals associated with positional unsaturated acyl groups (other than oleate and linoleate). The sample of “Corona” margarine consisted of a mixture of hydrogenated and unhydrogenated vegetable oils and butter (1.3%). The presence of butter in this sample was identified by the characteristic carbon shifts of the C-1 to C-4 carbon atoms of butyrate. The distribution of the fatty acids on the glycerol “backbone” also was estimated by this technique.

Oxidation of unsaturated fatty esters to the corresponding oxo derivatives was accomplished in moderate to high yields when the substrates were treated with palladium(II) chloride and p -benzoquinone in aqueous tetrahydrofuran (THF/H 2 O, 4:1 v/v) under ultrasound (20 kHz). Methyl 10-undecenoate furnished methyl 10-oxoundecanoate in 92% yield. Methyl oleate and trans -2-hexadecenoate furnished methyl 9(10)-oxoundecanoate (65%) and methyl 3-oxohexadecanoate (41%), respectively. Unsaturated fatty esters with a terminal double bond were more readily oxidized than those containing an internal double bond. Methyl trans -3,12-tridecadienoate gave only methyl 12-oxo- trans -3-tridecenoate (86%), while a cyclopentanoic fatty ester (methyl chaulmoograte) furnished a mixture of positional oxo-isomers: viz. methyl l-oxocyclopentane-2-tridecanoate and 1-oxocyclopentane-3-tridecanoate (51.5% total). Oxidation of methyl 12-hydroxy-, 12-azido-, 12-chloro- and 12-oxo- cis -9-octadecenoate furnished the corresponding 9-oxo-derivatives only. Methyl iso -ricinoleate (methyl 9-hydroxy- cis -octadecenoate) gave exclusively methyl 9-hydroxy-12-oxostearate. Without ultrasonication the same oxidation reactions at room temperature furnished low yields ( N , N -dimethylformamide (DMF).

13C nuclear magnetic resonance (NMR) spectroscopic analysis of the whole oil (triacylglycerols) ofBiota orientalis seeds confirms the presence of oleate [18:1(9Z)], linoleate [18:2(9Z, 12Z)], linolenate [18:3((9Z, 12Z, 15Z)], 20:3 (5Z, 11Z, 14Z), 20:4(5Z, 11Z, 14Z, 17Z), and saturated fatty acids in the acyl groups by comparing the observed carbon shifts with previously established shift data for model triacylglycerols. This technique shows that the saturated, 20:3 and 20:4 fatty acids are distributed mainly in the α-acyl positions, whereas oleate, linoleate, and linolenate are randomly acylated to the α- and β-positions of the glycerol “backbone”. Stereospecific hydrolysis of theBiota oil with pancreatic lipase, followed by chromatographic analysis of fatty esters, reveals the presence of trace amounts of 16:0(0.7%), 18:0(0.5%), 20:3 (0.4%), and 20:4 (1.3%) in the β-position of the glycerol “backbone”, which are undetectable by13C NMR technique on the whole oil. Semiquantitative assessment of the13C NMR signal intensities gives the relative percentages of the fatty acid distribution as: saturated 16:0, 18:0 (12.0% α-acyl), oleate (7.7% α-acyl 8.7% β-acyl), total linoleate and linolenate (31.7% α-acyl; 24.2% βacyl), total 20:3 and 20:4 (15.7% α-acyl). The13C NMR spectroscopic analysis of carrot seed oil identifies the presence of saturated (18:0), 18:1(6Z), 18:1(9Z), and 18:2(9Z, 12Z). The saturated fatty acid is found in the α-acyl positions. Semi-quantitative assessment of the signal intensities gives the relative percentages of the fatty acids as: 18:0 (4.5% α-acyl), 18:1(6Z) (49.6% α-acyl; 19.7% β-acyl), oleate (6.5% α-acyl; 8.6% β-acyl) and linoleate (5.2% α-acyl; 6.9% β-acyl).

Enzymatic hydrolysis of synthetic methyl 5-, 9-, and 12-thiastearates in aqueous media withCandida cyclindracea or porcine pancreatic lipases gave the corresponding fatty acids in 70–100% yield. Hydrolysis of the 3- and 4-positional isomers gave only 15–25% of the free thia fatty acids, suggesting discrimination against these isomers by lipases. No lipolysis was achieved with methyl 2-thialaurate under a range of reaction conditions. Esterification of the 3-, 4-, 5-, 9-, and 12-thiastearic acids withn-butanol inn-hexane using Lipozyme (immobilizedRhizomucor miehei) as the biocatalyst gave the corresponding butyl esters in 80–95% yield. Interesterification (acyl exchange) of triolein with methyl 9-thiastearate in the presence of Lipozyme showed the incorporation of 9-thiastearoyl chain at only one of the α-positions of triolein. In the case of methyl 2-thialaurate, no lipase-catalyzed acyl exchange reaction was possible. This study showed that the position of the sulfur atom in thia fatty esters affects the lipase-catalyzed hydrolysis and interesterification reactions.

Reaction of methyl 2- to 6-telluralaurate with sulfuryl chloride gives the corresponding tellurium dichloride (TeCl 2 ) derivatives quantitatively. The TeCl, group induces a strong de-shielding effect on the adjacent methylene groups. The 2-, 3- and 4-positional isomers are identified by 1 H-NMR spectroscopic analysis, and 13 C-NMR spectroscopic analysis allows all five positional isomers to be characterized.

Incubation of a 1-pyrroline ester [viz. methyl 8-(5-hexyl-1-pyrroline-2-yl)octanoate, 1] with bakers' yeast (Saccharomyces cerevisiae) gave the corresponding free fatty acid (1a, 52%). The C = N bond of the 1-pyrroline was not reduced by the yeast. Complete hydrolysis of compound 1 was successful using lipase of Candida cylindracea (CCL) or Lipolase (Rhizomucor miehei) under stirred or ultrasound condition. Fatty esters containing a pyrrolidine [viz. methyl 8-(cis/trans-5-hexyl-pyrrolidine-2-)octanoate, 2] or N-methyl pyrrolidine [viz. methyl 8-(cis-5-hexyl-N-methyl-pyrrolidine-2-)octanoate, 3] system in the alkyl chain were not hydrolyzed by either CCL or Lipolase, unless conducted in an ultrasonic bath. The hydrolytic activities of the enzymes appeared to be strongly affected by the stereochemistry of the N-heterocyclic ring system. Chemical hydrolysis of compounds 1-3 gave the corresponding fatty acid N-HCl salts.

The 13C-NMR properties of a total of 22 synthetic (Z)-ethylenic and (E)-ethylenic triacylglycerols of type AAA (containing isomeric positional unsaturated fatty acid homologues with the ethylenic bond located at Δ2 to Δ12 position) have been studied. The results show that the shifts of the glyceryl carbon atoms are only significantly affected when the unsaturated center is located at either the Δ2 or Δ3 position of the acyl chains. The ethylenic carbon atoms in the α- and β-acyl chains are fully resolved except in two cases, viz. 12:1(3Z)/12:1(3Z)/12:1(3Z) and 15:1(6E)/15:1(6E)/15:1(6E), where the shifts of the C-4 and C-7 ethylenic carbon atoms in the α- and β-acyl chains, respectively, remain unresolved. From the carbon chemical shift values of the ethylenic carbons and the difference between the shift values of these nuclei in the same acyl chain, it is possible to determine the position of the unsaturated center by this technique. Using the signal pattern displayed by the ethylenic carbon nuclei in the spectra, the positional distribution of short-chain fatty acid moieties in the glycerol ‘backbone’ can be determined. Methylene carbon atoms in the α- and β-acyl chain, which are located close to the acyl function are resolved up to the C-6 carbon atom. It is possible to locate the position of the unsaturated center in the acyl chains as remote as the Δ12 position and the position (α- or β-acyl) of the unsaturated acyl chains on the glyceryl backbone of these triacylglycerol molecules by 13C-NMR spectroscopy.

The 13C-NMR spectroscopic properties of eight triacylglycerols of type AAA containing polyunsaturated fatty acids, viz. 18:2(9Z,12Z) 18:2(9Z,12E), 18:2(9E,12Z) 18:2(9E,12E), 18:2(8E,12Z) 18:3(9Z,12Z,15Z) 20:3(5Z,11Z,14Z) and 20:4(5Z,11Z,14Z,17Z), have been studied. From the carbon shift values of the various carbon atoms, it is possible to confirm the position and geometry of the unsaturated centers in the acyl chains. Many of the similarly positioned carbon atoms from C-1 to C-14, whether arising from methylene or ethylenic carbon nuclei in the α- and β-acyl chains, are resolved to give characteristic pairs of signals. By making use of the differences in shift values for carbon atoms of similarly positioned carbon atoms in the α- and β-acyl chains, the assignment of the chemical shifts of the various nuclei is readily achieved. A further 21 mixed triacylglycerols containing a mixture of saturated (18:0) acetylenic [18:1(5A), 18:1(6A) or 18:1(7A)], mono-ethylenic [18:1(5Z) 18:1(6Z), 18:1(7Z), 18:1(7E) or 18:1(9Z)] and diethylenic [18:2(9Z,12Z)] acyl groups have been studied. The nature (type of unsaturation and position of unsaturated centers) and distribution of the various acyl groups on the glycerol ‘backbone’ of these mixed triacyl glycerols are determined by this technique.

The 1H-NMR spectroscopic properties of 15 synthetic homologous saturated triacylglycerols of type AAA and 16 mixed saturated triacylglycerols of type ABA and AAB have been studied. Triacylglycerols containing short-chain fatty acids (2:0–6:0) are readily identified. Triacylglycerols containing medium- and long-chain fatty acid components are not differentiated. From the analysis of 19 acetylenic triacylglycerols of type AAA, ABA and AAB (containing positional isomers of acetylenic fatty acids), it is only possible to characterize triacylglycerols with acyl groups containing the acetylenic bond at the Δ2−Δ5 position. 1H-NMR analysis could not confirm the positions (α- or β-acyl) of the acetylenic acids in mixed triacylglycerols. In the study of 22 ethylenic triacylglycerols of type AAA containing positional isomers of (Z)- or (E)-ethylenic acids, molecules containing an ethylenic bond in the Δ2 position of the acyl chains were readily characterized, as the ethylenic protons in the α- and β-acyl chains were fully resolved. Triacylglycerols containing an unsaturated center at the position were characterized by the shifts of the 2-H protons. The spectra of the remaining triacylglycerol molecules were very similar and the position of the ethylenic system could not be determined by this technique.

The 13 C-NMR signals of the unsaturated carbons in triacylglycerols with monoenoic and monoynoic chains were evaluated as rational functions. Corresponding to previous results on fatty acids and methyl esters, the signals of the ethylenic carbons are proportional to the negative third power of the position of the unsaturation in the chain. The signals of the acetylenic carbons are proportional to the negative second power of the position of the unsaturation. The POSE (position of shift equivalence) of the unsaturated carbons is more remote from C1 for triacylglycerols than for free fatty acids and methyl esters.

Using a combination of selective irradiation 1H nuclear magnetic resonance experiments and two-dimensional 1H-13C correlation spectroscopy spectral analysis of homoallylic and bis homoallylic substituted (azido, acetoxy, chloro and oxo) fatty ester derivatives, the carbon shifts of the ethylenic carbon atoms were determined. In the case of methyl 12-azido-9Z-octadecenoate (homoallylic), the carbon chemical shifts of the ethylenic C-9 and C-10 carbon nuclei are 133.092 and 124.596 ppm, respectively. In methyl 9-azido-12Z-octadecenoate (bis homoallylic), the carbon chemical shift of the ethylenic C-12 and C-13 carbon nuclei are 128.118 and 131.243 ppm, respectively.

Enrichment ofcis-5 polyunsaturated fatty acids [20:3(5c,11c,14c), 4.3% and 20:4(5c,11c,14c,17c), 11.3%] fromBiota orientalis seed oil was carried out by lipase-catalyzed selective esterification and hydrolysis reactions. Lipases fromRhizomucor miehei (Lipozyme),Candida cylindracea and porcine pancreas were used. Lipozyme-catalyzed esterification ofBiota fatty acids withn-butanol inn-hexane allowed 20:3 and 20:4 (as fatty acids) to be enriched to a maximum level of 52.9%, and in the presence ofC. cylindracea lipase 61.5% enrichment was achieved. Esterification with pancreatic lipase was poor with low levels of enrichment of 20:3 and 20:4 (22%). A multigram scale esterification of the free fatty acids fromBiota seed oil by repeated treatment of the isolated fatty acid fraction withn-butanol inn-hexane in the presence ofC. cylindracea lipase furnished an enrichment yield of 72.5% of a mixture of 20:3 and 20:4 fatty acids. Urea fractionation of the free fatty acids ofBiota oil gave an initial enriched fraction of 20:3 (9.5%) and 20:4 (25.2%) which, upon treatment withC. cylindracea lipase inn-butanol andn-hexane, gave an enriched fraction of 85.3% of 20:3 and 20:4 fatty acids. Partial hydrolysis of the triglycerides ofBiota oil byC. cylindracea lipase in potassium phosphate buffer at 25°C resulted in a 2.8-fold enrichment ofcis-5 polyunsaturated fatty acids (40.8% of 20:3 and 20:4) as contained in the unhydrolyzed acylglycerol fractions.

Ultrasound (20 kHz)-assisted epoxidation of unsaturated fatty esters with m-chloroperoxybenzoic acid (MCPBA) in water was successfully carried out in less than 30 min. Epoxidation of unsaturated fatty esters containing an internal ethylenic system was more readily accomplished than with substrates containing a terminal ethylenic bond. The rate of epoxidation of the same unsaturated fatty esters using magnesium monoperoxyphthalate in aqueous ethanol was much slower than reactions with MCPBA.

Autoxidation products of synthetic methyl 9,12-epoxy-octadeca-9,11-dienoate (MEFA) were investigated by gas chromatography-mass spectrometry analysis and tested for bacterial urease inhibition. A suspension of oxidized MEFA in 10% Tween 80 was an effective inhibitor for bacterial urease extract fromHelicobacter pylori (I50=1.3 mM) and for commercial urease fromBacillus pasteurii (I50=0.06 mM). The urease inhibitory effect was cancelled by adding cysteine to the reaction mixture. The total content of biologically active oxidized products in the mixture was found to be 6.2%. Dioxo-ene derivatives of MEFA on the thin-layer chromatography plate surface were converted into more stable compounds, whose formation in the mixture reduced inhibition ofB. pasteurii to about 2% of the former level. The mechanism of urease inhibition is supposed to involve the interaction of the thiol groups of the enzyme’s active center with the inhibitor molecules.

Methyl 9,12-epoxy-10-phenyl-9,11-octadecadienoate was prepared by acid catalyzed cyclization of methyl 9,12-dioxo-10-phenyloctadecanoate, which was derived from the oxidation of methyl 9-hydroxy-12-oxo-10-phenyloctadecanoate. The latter was exclusively obtained from methylcis-9,10-epoxy-12-oxooctadecanoate with phenyllithium in the presence of copper (I) bromide. A mixture of positional isomers, methyl 9,12-epoxy-10(11)-phenyl-9,11-octadecadienoates, was also prepared by another route. The spectroscopic properties of the various intermediates and products were studied. The positional isomers of the phenyl substituted furanoid fatty esters were characterized by(13)C nuclear magnetic resonance spectrometry.

Dehydration of methyl 9,12-dihydroxy-10- trans -octadecenoate ( 8 ) gave different products depending on the reagents used. Treatment of compound 8 with p -toluenesulfonic acid in 1,2-dichloroethene gave a mixture of methyl 9-oxo-10- trans -octadecenoate and 12-oxo-10- trans -octadecenoate (82%). Reaction of compound 8 with chlorotrimethylsilane and sodium iodide in acetonitrile furnished a conjugated C 18 diene ester (18:2 (9 t , 11 t )) (72%). And reaction of compound 8 with copper(II) sulfate adsorbed on silica in methylbenzene under reflux gave a mixture of C 18 triene ester isomers (18:3 (7 t ,9 t ,11 t ), 18:3 (8 t ,10 t ,12 t ) and 18:3 (9 t ,11 t ,13 t )) (94%).

The effects of 5c,11c,14c-eicosatrienoic acid (20:3BSO) and 5c,11c,14c,17c-eicosatetraenoic acid (20:4BSO), polyunsaturated fatty acids (PUFA) contained in Biota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or alpha-linolenic acid (ALA) under similar conditions. The potential effect of ethyl 20:4BSO as an essential fatty acid also was examined in comparison with the ethyl esters of LA, ALA and gamma-linolenic acid (GLA). BSO- and ALA-rich fat decreased the concentration of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA-rich fat. BSO was more effective in reducing plasma cholesterol concentrations than was the ALA-rich fat. Dietary BSO markedly decreased the hepatic triglyceride concentration as compared to the LA-rich or ALA-rich fats. Aortic production of prostaglandin I2 tended to decrease in rats fed BSO or ALA-rich fat compared to those fed the LA-rich fat. Adenosine diphosphate-induced platelet aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of rats fed BSO was lowest compared to that of rats fed ALA-rich or LA-rich fats. Administration of 20:4BSO, ALA or GLA to essential fatty acid-deficient rats decreased the ratio of 20:3n-9 to AA in liver PC to the same extent; administration of LA was more effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from those of LA and ALA. It is also suggested that 20:4BSO may exhibit some essential fatty acid effects.

Reaction of 1-mesyloxynonane with methyl 8-aminooctanoate gives methyl 9-azastearate (I, 20%); treatment of methyl 9(10),10(9)-azidohydroxyoctadecanoate and methyl 10-azido-12-hydroxyoctadecanoate with triphenylphosphine furnishes the corresponding aziridine derivative (II, 75%) and two geometric azetidine isomers (IIIa and IIIb, 37%), respectively. The aza function in compound I, the aziridine nucleus in compound II and the azetidine system in compounds IIIa, IIIb were characterized by1H nuclear magnetic resonance (NMR) and13C NMR spectral analysis. The infrared spectral analyses of compounds (I), (II) and (IIIa,IIIb) showed characteristic absorption bands at 3200–3300 cm−1 for the N-H stretching vibration.

Sulfoxidation of the positional isomers of methyl thialaurate with m-chloroperoxybenzoic acid gave the corresponding sulfinyl and sulfonyl derivatives. In the 1H-NMR spectroscopic analysis, the sulfoxide function exerted a weaker deshielding effect than the sulfone group on the chemical shift of the protons of the adjacent methylene groups. The shift of the protons of the unperturbed α-methylene groups adjacent to the sulfone and sulfoxide function appeared at δ 2.97 and 2.67, respectively. It was possible to identify 7 of the 10 sulfinyl and sulphonyl derivatives by 1H-NMR spectroscopy. In the 13C-NMR spectroscopic analysis, the effect of the sulfinyl and sulfonyl function on the chemical shift of the adjacent α- and β-methylene carbons was quite similar, but significant enough to permit further differentiation of positional isomers. The chemical shifts of the α- and β-methylene carbons located adjacent to the sulfinyl function appeared at about 52.2 and 22.5 ppm, respectively. In the case of sulfonyl derivatives the shift of the α and β-methylene carbon atoms were found at about 52.4 and 21.6 ppm. It was possible to identify each positional isomer of the sulfinyl and sulfonyl derivatives of methyl thialaurate by this technique.

Furan ring opening with benzohydroxamic acid of methyl 9,12-epoxy-9,11-octadecadienoate gave a mixture of positional isomers of conjugated methyl 3-phenyl-1,4,2-dioxazolyl C18-enone esters 6a,6b. Michael addition of diethyl malonate anion to the conjugated enone system of 6a,6b furnished the corresponding malonyl intermediates 7a,7b, which upon removal of the dioxazole ring by hydrolysis gave methyl 10- and 11-dicarbethoxymethyl-9,12-dioxooctadecanoate 8a,8b. Cyclization of the latter gave the trisubstituted C18 furanoid fatty esters 9a,9b, containing the malonate ester function at the 3-/4-position of the furan ring. Base hydrolysis of compounds 9a,9b gave the corresponding tricarboxylic acid derivatives 10a,10b, which were esterified to the trimethyl esters 11a,11b in BF3/MeOH. When a mixture of 9a,9b was refluxed with Na2CO3/MeOH, hydrolysis of the malonate ester function was followed by decarboxylation to yield a-CH2COOH substituent at the 3-/4-position of the furan ring (12a, 12b). Esterification of the latter with BF3/MeOH gave the corresponding methyl diester derivatives 13a,13b. When a mixture of tricarboxylic acids 10a,10b was heated at 160–180°C for 6 hr, exhaustive decarboxylation of malonic acid function furnished a methyl group at the 3-/4-position of the furan nucleus. Esterification of the decarboxylated product gave a mixture of trisubstituted furanoid compounds 14a,14b (overall yield 28%). The procedure constitutes a novel method for the introduction of a methyl groupvia a malonic acid group to the 3-/4-position of the furan ring of a 2,5-disubstituted C18 furanoid fatty ester.

A C18 1-pyrroline fatty ester, methyl 8-(5-hexyl-2-pyrrolin-1-yl)octanoate (1), was prepared from methyliso-ricinoleate. The C=N bond of the pyrroline ring was oxidized bym-chloroperoxy-benzoic acid to yield a mixture of oxaziridine isomers 2a,2b, which decomposed during gas chromatographic analysis to a 2,5-disubstituted pyrrole derivative, methyl 8-(5-hexyl-1H-pyrrole-2-)octanoate (3). Compound 3 was also obtained by reaction of 2a,2b with dilute HCl in methanol. Reaction of compound 1 with iodo-methane formed anN-methyl iminium iodide intermediate 4, which on reduction with sodium borohydride furnished a mixture ofcis/trans-N-methyl-2,5-disubstituted pyrrolidine derivatives, methyl 8-(cis/trans-5-hexyl-N-methyl-pyrrolidine-2-)octanoates 5a,5b. Reduction of compound 1 with NaBH4 gave a mixture ofcis/trans-isomers of 2,5-disubstituted pyrrolidine derivatives, methyl 8-(5-hexyl-pyrrolidine-2-)octanoates 6a,6b. Acetylation of compounds 6a,6b with acetic anhydride furnished the correspondingN-acetyl pyrrolidines 7a,7b. When compound 1 was treated with perchloric acid, the corresponding iminium perchlorate derivative, methyl 8-(5-hexyl-1-pyrrolinium perchlorate-2-)octanoate 8 was obtained. The structures of the various derivatives were characterized by a combination of chromatographic, mass spectral and spectroscopic techniques.