Petroselinic Acid Research Articles

Gradient reversed-phase high-performance liquid chromatography of saturated, unsaturated and oxygenated free fatty acids and their methyl esters

Abstract Reversed-phase C18 high-performance liquid chromatography (HPLC) separation of 49 free fatty acids and their methyl esters is reported here. Separation is achieved using methanol/water gradients and detection by either UV absorbance or evaporative light scattering. The factors decreasing retention times are: keto group, hydroxy group, epoxy group, triple bond, shortened chain length (C2H4 shorter), cyclopropenyl group, double bond, and cyclopropanyl group, in approximate correspondence to the order of their decreasing polarity. Fatty acids with cis-double bond, cis-epoxy and threo-dihydroxy substituents elute slightly earlier than the corresponding trans-double bond, trans-epoxy and erythro-dihydroxy fatty acids. These geometric isomers are better separated as free fatty acids than their methyl esters. For monounsaturates, cis-double bond at C-10 of the methyl ester of octadecenoic acid decreased the retention times most, with slightly increasing retention time as the double bond shifts toward either end of the chain. The trans-double bond of methyl esters of octadecenoic acids showed similar results. The effect of single double bond position in the HPLC of free octadecenoic acids is similar except the shortest retention time occurs when the double bond is at C-11. Two of the C18 columns in series achieve the separation of double bond positional isomers (free fatty acids), cis-7-octadecenoic acid and petroselinic acid (cis-6) at a resolution Rs = 1.05.

Steric Structures of Triacylglycerols in the Seed Oil of Carrot Daucus carota L. var. sativa DC.

The steric structures of the triacylglycerols (TGs) in the seed oil of carrot Daucus carota L. var. sativa DC. were studied by the stereospecific analysis of the acyl distributions using the chiral-phase high-performance liquid chromatography of the monoacylglycerol derivatives. Total fatty acids of the seed oil TGs contained 71 mol % petroselinic acid (6-18 : 1), 12 mol % oleic acid (9-18 : 1), 11 mol %linoleic acid (18 : 2 n-6), and 4 mol % palmitic acid (16 : 0). Fatty acid percents in each sn-1, sn-2 and sn-3 position of the TGs were 6-18 : 1 (38, 23 and 40 %), 9-18 : 1 (21, 66 and 13 %), and 18 : 2 n-6 (20, 65and 15 %). Structures and estimated contents of the major TG components in the carrot seed oil wasfound to be (6-18 : 1) (6-18 : 1) (6-18 : 1) 3248 %, (6-18 : 1) (9-18 : 1) (6-18 : 1) 1725 %, (6-18 : 1) (18 : 2 n-6) (6-18 : 1) 1522 %. Petroselinic acid distributes preferentially at the sn-1 and sn-3 positionsin the carrot seed oil TGs in analogy with 16 : 0 and 18 : 0 in the ordinary seed oil TGs.

Determination of the Petroselinic Acid in Seeds of Coriandrum sativum by Gas Liquid Chromatography as n‐Butyl Esters

AbstractOleic acid (18:1 n9), vaccenic acid (18:1 n7). and petroselinic acid (18:1 n12) can not be separated by gas chromatography (GLC) as their methylesters. But separations of their n‐butyl esters are feasible. With 0.1 mol Na‐tert‐butanol as catalyst, dissolved in n‐butanol, an extraction from the seed grist and simultaneous transbutylation of the lipids can be achieved within 20 min at room temperature. Using a capillary column (60 m DB‐23, 0.25 μ, J&W, No. 122‐2362), hydrogen as carrier gas and an oven temperature of 220° C, one analysis can be performed within 13 min.

Accumulation of petroselinic acid in developing somatic carrot embryos

Developing somatic embryos of carrots accumulated up to 23 mg g 1̄ dry wt of petroselinate, most of which was incorporated into triacylglycerols. Both triacylglycerol and petroselinate accumulation in the embryos were increased by addition of abscisic acid to the culture medium.

Manipulation of seed oil content to produce industrial crops

Three examples are presented of the modification of seed oil quality by molecular genetics, in order to create potentially valuable industrial feedstocks. (a) Cloning of the desaturase gene responsible for the formation of petroselinic acid from the spice plant Coriander has allowed for the insertion of this gene into rapeseed, in an attempt to obtain transgenic rapeseed plants with a high seed petroselinic acid phenotype. The possibility that additional genes other than this desaturase may be required for petroselinic acid formation is discussed. (b) Attempts to achieve very high erucic acid phenotypes in rapeseed are concentrated around cloning an acyltransferase gene from meadowfoam. The transfer of this gene into rapeseed may result in the accumulation of a very high erucic acid seed oil, in contrast to current high erucic varieties which only contain between 45% and 55% of this useful industrial feedstock. (c) Attempts to clone the hydroxylase gene responsible for the accumulation of ricinoleic acid in castorbean are described. A biochemical strategy based upon solubilisation and purification of the hydroxylase protein was unsuccessful due to the loss of hydroxylase activity in the presence of detergents. A differential screening approach was therefore adopted. Antibodies were raised against microsomal membrane fractions from castorbean seeds at a late stage of development corresponding to their maximum oleate hydroxylase activity. The purified IgG fraction was then incubated in the presence of microsomal membrane fractions from either very young or mature castorbean seeds which had no oleate hydroxylase activity. This resulted in the isolation of a population of castorbean IgGs specific for microsomal membrane proteins which were only present at the stage of maximum oleate hydroxylase activity. The IgG fraction was then used to screen a λ-ZAP cDNA expression library prepared from poly A +-enriched RNA, extracted from seeds at the late developmental stage. From these antibody screens, 43 positive cDNA clones were isolated and sequenced from the 5′ end to an average of 250 bases each. All but two of the cDNA clones were eliminated due to (a) sequence similarity with previously known proteins or (b) inappropriate expression patterns of the corresponding mRNAs following Northern blot analysis. Potential sequence motifs in the oleate hydroxylase, which may be useful for the isolation or identification of candidate hydroxylase cDNA clones, such as the two clones isolated in this study, are discussed.

Estudio de la composición en ácidos grasos del aceite de las semillas en algunas plantas silvestres españolas

The fatty acid composition of 34 species of plants from a variety of families that grow wild in the Iberian Peninsula was analysed. The aim to the survey was to indentify oils that contain a mix of fatty acids that from a qualitative or quantitative point of view have a commercial value. Because of the diverse taxonomic origin of the samples, the oil content between species was very variable, fluctuating between an average value of 3.4% in the Caryophyllaceae and 31.1% in Euphorbiaceae . Like the oil content, the fatty acid composition was quite variable, but, in general, the main fatty acids were palmitic, oleic, linoleic and linolenic acid, while in the Brassicaceae and in the Apiaceae erucic acid and petroselinic acid were the principal fatty acids respectively.

Metabolic Evidence for the Involvement of a [delta]4-Palmitoyl-Acyl Carrier Protein Desaturase in Petroselinic Acid Synthesis in Coriander Endosperm and Transgenic Tobacco Cells.

We have previously demonstrated that the double bond of petroselinic acid (18:1[delta]6cis) in coriander (Coriandrum sativum L.) seed results from the activity of a 36-kD desaturase that is structurally related to the [delta]9-stearoyl-acyl carrier protein (ACP) desaturase (E.B. Cahoon, J. Shanklin, J.B. Ohlrogge [1992] Proc Natl Acad Sci USA 89: 11184-11188). To further characterize the biosynthetic pathway of this unusual fatty acid, 14C-labeling experiments were conducted using developing endosperm of coriander. Studies were also performed using suspension cultures of transgenic tobacco (Nicotiana tabacum L.) that express the coriander 36-kD desaturase, and as a result produce petroselinic acid and [delta]4-hexadecenoic acid. When supplied exogenously to coriander endosperm slices, [1-14C]palmitic acid and stearic acid were incorporated into glycerolipids but were not converted to petroselinic acid. This suggested that petroselinic acid is not formed by the desaturation of a fatty acid bound to a glycerolipid or by reactions involving acyl-coenzyme As (CoA). Instead, evidence was most consistent with an acyl-ACP route of petroselinic acid synthesis. For example, the exogenous feeding of [1-14C]lauric acid and myristic acid to coriander endosperm slices resulted in the incorporation of the radiolabels into long-chain fatty acids, including primarily petroselinic acid, presumably through acyl-ACP-associated reactions. In addition, using an in vitro fatty acid biosynthetic system, homogenates of coriander endosperm incorporated [2-14C]malonyl-CoA into petroselinic acid, of which a portion was detected in a putative acyl-ACP fraction. Furthermore, analysis of transgenic tobacco suspension cultures expressing the coriander 36-kD desaturase revealed significant amounts of petroselinic acid and [delta]4-hexadecenoic acid in the acyl-ACP pool of these cells. Also presented is evidence derived from [U-14C]nonanoic acid labeling of coriander endosperm, which demonstrates that the coriander 36-kD desaturase positions double bonds relative to the carboxyl end of acyl-ACP substrates. The data obtained in these studies are rationalized in terms of a biosynthetic pathway of petroselinic acid involving the [delta]4 desaturation of palmitoyl-ACP by the 36-kD desaturase followed by two-carbon elongation of the resulting [delta]4-hexadecenoyl-ACP.

Apparent Role of Phosphatidylcholine in the Metabolism of Petroselinic Acid in Developing Umbelliferae Endosperm.

Studies were conducted to characterize the metabolism of the unusual fatty acid petroselinic acid (18:1cis[delta]6) in developing endosperm of the Umbelliferae species coriander (Coriandrum sativum L.) and carrot (Daucus carota L.). Analyses of fatty acid compositions of glycerolipids of these tissues revealed a dissimilar distribution of petroselinic acid in triacylglycerols (TAG) and the major polar lipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Petroselinic acid comprised 70 to 75 mol% of the fatty acids of TAG but only 9 to 20 mol% of the fatty acids of PC and PE. Although such data appeared to suggest that petroselinic acid is at least partially excluded from polar lipids, results of [1-14C]acetate radiolabeling experiments gave a much different picture of the metabolism of this fatty acid. In time-course labeling of carrot endosperm, [1-14C]acetate was rapidly incorporated into PC in high levels. Through 30 min, radiolabel was most concentrated in PC, and of this, 80 to 85% was in the form of petroselinic acid. One explanation for the large disparity in amounts of petroselinic acid in PC as determined by fatty acid mass analyses and 14C radiolabeling is that turnover of these lipids or the fatty acids of these lipids results in relatively low accumulation of petroselinic acid mass. Consistent with this, the kinetics of [1-14C]acetate time-course labeling of carrot endosperm and "pulse-chase" labeling of coriander endosperm suggested a possible flux of fatty acids from PC into TAG. In time-course experiments, radiolabel initially entered PC at the highest rates but accumulated in TAG at later time points. Similarly, in pulse-chase studies, losses in absolute amounts of radioactivity from PC were accompanied by significant increases of radiolabel in TAG. In addition, stereospecific analyses of unlabeled and [1-14C]acetate-labeled PC of coriander endosperm indicated that petroselinic acid can be readily incorporated into both the sn-1 and sn-2 positions of this lipid. Because petroselinic acid is neither synthesized nor further modified on polar lipids, the apparent metabolism of this fatty acid through PC (and possibly through other polar lipids) may define a function of PC in TAG assembly apart from its involvement in fatty acid modification reactions.

Specificities of the Acyl-Acyl Carrier Protein (ACP) Thioesterase and Glycerol-3-Phosphate Acyltransferase for Octadecenoyl-ACP Isomers (Identification of a Petroselinoyl-ACP Thioesterase in Umbelliferae).

This study was designed to address the question: How specific for double bond position and conformation are plant enzymes that act on oleoyl-acyl carrier protein (ACP)? Octadecenoyl-ACPs with cis double bonds at positions [delta]6, [delta]7, [delta]8, [delta]9, [delta]10, [delta]11, or [delta]12 and elaidyl (18:1[delta]9trans)-ACP were synthesized and used to characterize the substrate specificity of the acyl-ACP thioesterase and acyl-ACP:sn-glycerol-3-phosphate acyltransferase. The two enzymes were found to be specific for the [delta]9 position of the double bond. The thioesterase was highly specific for the [delta]9 cis conformation, but the transferase was almost equally active with the cis and the trans isomer of 18:1[delta]9-ACP. In plants such as the Umbelliferae species coriander (Coriandrum sativum L.) that accumulate petroselinic acid (18:1[delta]6cis) in their seed triacylglycerols, a high petroselinoyl-ACP thioesterase activity was found in addition to the oleoyl-ACP thioesterase. The two activities could be separated by anion-exchange chromatography, indicating that the petroselinoyl-ACP thioesterase is represented by a distinct polypeptide.

Substrate specificities of lipases in view of kinetic resolution of unsaturated fatty acids

Several commercially available lipases have been evaluated with regard to their substrate specificity in the esterification of fatty acids having specific positions of cis double bonds, e.g. petroselinic acid (n-12 18:1), alpha-linolenic acid (n-3 18:3), gamma-linolenic acid (n-6 18:3), stearidonic acid (n-3 18:4), dihomogamma-linolenic acid (n-6 20:3), eicosapentaenoic acid (n-3 20:5) and docosahexaenoic acid (n-3 22:6), with n-butanol. A common feature of most lipases, e.g. those from Penicillium cyclopium, Candida cylindracea, Mucor miehei, Rhizopus arrhizus and Penicillium sp. is that fatty acids having the first double bond from the carboxyl end as a cis-4 (n-3 22:6), cis-6 (n-12 18:1, n-6 18:3, n-3 18:4) or a cis-8 (n-6 20:3) double bond are strongly discriminated against compared to the other fatty acids, such as myristic acid (14:0), the reference standard, and n-3 18:3. In the case of the lipase from porcine pancreas, however, the discrimination against the above fatty acids is not as strong as with the other lipases. In contrast, the lipase from Chromobacterium viscosum shows a preference for n-12 18:1, n-6 18:3 and n-3 18:4. The observed substrate specificities can be utilized for enrichment of particular fatty acids by lipase-catalysed kinetic resolution from fatty acid mixtures, derived from naturally occurring fats and other lipids.

Capillary GLC fatty acid fingerprints of seed lipids—a tool in plant chemotaxonomy?

AbstractThe fatty acid composition of the seed lipids of plants, in contrast to leaf lipids, may contain highly specific unusual fatty acids, which are often correlated to plant family. For example, petroselinic acid is typical for the Apiacea family, cyclopropene fatty acids are typical for the Malvaceae family, and cyclopentene‐ring containing fatty acids for the Flacourtiaceae family. Other fatty acids may be characteristic for certain sub‐families or only for certain species of plants within a family or genus. γ‐Linolenic acid, Δ5–18:3 and Δ5–20:3 fatty acids and others may occur in several plant families, but are still linked to certain related species only. They can be analyzed by high‐resolution capillary GLC. Particularly interesting is the situation in the family Ranunculaceae. GLC fingerprints of fatty acids are shown that may indicate a closer or less close relationship between species within this family.

Alkylaluminium Dichloride Induced Friedel‐Crafts Acylation of Unsaturated Carboxylic Acids and Alcohols

AbstractThe ethylaluminium dichloride induced Friedel‐Crafts acylation of unsaturated carboxylic acids, for example 10‐undecenoic acid (1a) and oleic acid (5a), and of the respective alcohols 1b and 5b with acyl chlorides and cyclic acyl anhydrides gave the corresponding long‐chain β,γ‐unsaturated ketones 3, 6/7, 11 and 13/14 with ω‐carboxy and ω‐hydroxy functions, respectively. The intramolecular cyclization of petroselinic acid chloride (17) yielded (E)‐2‐dodecylidenecyclohexanone (18). Catalytic hydrogenation gave the respective saturated ketones 4, 8/9, 12, 15/16 and 19.

Estolides from meadowfoam oil fatty acids and other monounsaturated fatty acids

The formation of estolides was detected during the studies on dimerization of meadowfoam oil fatty acids. By adjusting the reaction conditions, it was possible to produce monoestolides with little dimer or trimer formations. Estolides have potential use in lubricant, cosmetic and ink formulations and in plasticizers. This paper reports the conditions for production of estolides from mixed meadow‐foam fatty acids, commercial oleic acid, high‐oleic sun‐flower oil fatty acids,cis‐5,cis‐13‐docosadienoic acid, petroselinic acid and linoleic acid.

Free‐radical Cyclization of Petroselinic Acid

AbstractPetroselinic acid was cyclized via methyl 2‐iodopetroselinate (1) with tributyltin hydride to give methyl trans‐ and cis‐2‐dodecyl‐1‐cyclopentanecarboxylate (2). The atom‐transfer method with hexabutylditin resulted in the formation of bicyclic γ‐lactones 4 and methyl trans‐2‐(1′‐iodododecyl)‐1‐cyclopentanecarboxylate (trans‐5). The same products were obtained with the new initiator system SnCl2/AgOAc. This method showed, if compared with the other methods, the shortest reaction time, the highest yield and stereoselectivity combined with a very simple workup procedure and the use of less toxic chemicals.

Petroselinic Acid from the Ripe Berries of Aralia spinosa

AbstractActivity-directed fractionation of the 95% ethanol extract of the berries of Aralia spinosa L. (Araliaceae) led to the isolation of cis-6-octadecenoic acid (1) (petroselinic acid) as the major bioactive compound. This is the first report of this compound being isolated from the genus Aralia and of its toxicity. In this paper we reported the complete spectral data of 1.

Radikalische Cyclisierung von Petroselinsäure

AbstractPetroselinsäure wurde in 2‐Iodpetroselinsäuremethylester (13) übergeführt und mit Tributylzinnhydrid zu trans‐ und cis‐2‐Dodecyl‐1‐cyclopentancarbonsäuremethylester (14) umgesetzt. Die Atomtransfermethode mit Hexabutyldizinn führt zu bicyclischen γ‐Lactonen 16 und trans‐2‐(1′‐Iodododecyl)‐1‐cyclopentancarbonsäuremethylestern 17. Diese Produkte werden auch erhalten, wenn man das neue Initiatorsystem SnCl2/AgOAc einsetzt. Im Vergleich mit den anderen Methoden zeigt dieses neue System die kürzeste Reaktionszeit, die höchste Ausbeute und Stereoselektivität, verbunden mit der einfachsten Aufarbeitung und der Verwendung der ungiftigsten Chemikalien.

Determination of the Petroselinic Acid Content in Seeds of Coriandrum sativum by Gas Liquid Chromatography

AbstractWith dimethyldisulfide the methylthio‐derivatives of unsaturated fatty acid methylesters are readily formed within 30 min at 70°C. Whereas the analysis of oleic and petroselinic acid methyl esters by gas liquid chromatography is very time consuming (separation time: 1 hour), their corresponding methylthio‐derivatives can be quantitatively determinated within 14 min.

Synthesis and biological properties of hydroxythioether fatty acids related to leukotrienes: Antagonists and agonists of slow-reacting substance of anaphylaxis (SRS-A)

A series of 6-hydroxy-7-thioether and 6-thioether-7-hydroxy derivatives of commercially available petroselinic acid and 5-hydroxy-6-thioether derivatives of fatty acids containing an aromatic moiety were synthesized. Several of the compounds have exhibited SRS-A antagonist ( eg, 5, 10)/agonist ( eg, 34, 35) activity. Compound 5 antagonized SRS-A-induced contractions of the isolated guinea pig ileum with IC 50 = 0.09 μM.

Maximierung der Samenerträge und wertgebenden Inhaltsstoffe von Fenchel (Foeniculum vulgare M.) I

AbstractZiel der vorliegenden Arbeit war die Maximierung der Samenerträge und wertgebenden Inhaltsstoffe von Fenchel durch Voranzucht gegenüber Direktaussaat, eine ertragswirksame N‐Düngung und Wahl geeigneter Erntetermine an 2 Standorten mit verschiedenen ökologischen Bedingungen. Die Versuche wurden 1990 und 1991 in Durmersheim (Rheintal) und in Ensmad (Schwäbische Alb) mit einer langjährigen Jahresdurchschnittstemperatur von 9.8°C bzw. 6.9°C durchgeführt. Voranzucht erzielte gegenüber Direktaussaat in Durmersheim in beiden Jahren den höchsten Samenertrag. Höchsterträge an Petroselinsäure und an ätherischen Ölen erzielten jedoch in Durmersheim 1991 sowohl Voranzucht‐ als auch Aussaat‐Varianten. In Ensmad entwickelten nur die Voranzucht‐Varianten erntefähige Samen. Eine Stickstoffdüngung führte bei Fenchel zu Ertragssteigerungen. Sie hatte einen positiven Einfluß auf den Samenertrag, den Ertrag an Petroselinsäure und an ätherischen Ölen. Mit zunehmender Reife der Früchte nahm der Samenertrag durch Ausfall der Samen ab. Der Ertrag an Petroselinsäure und an ätherischen Ölen nahm ebenfalls ab.

Separation of petroselinic (cis‐6 18:1) and oleic (cis‐9 18:1) acids by gas‐liquid chromatography of their isopropyl esters

Petroselinic (cis‐6 18:1) and oleic (cis‐9 18:1) acids that occur together in Umbelliferae seeds can be resolved by gasliquid chromatography (GLC) of their methyl or isopropyl esters on a 50 m × 0.25 mm fused‐silica capillary column coated with a 100% cyanopropyl polysiloxane stationary phase (CP Sil 88). The use of isopropyl esters instead of methyl esters increases the difference between equivalent chainlengths from 0.06 carbon unit up to 0.08. This is sufficient to obtain an almost base‐line resolution between the two components.cis‐Vaccenic acid is completely separated from oleic acid in both derivative forms. GLC of fatty acid isopropyl esters on an appropriate capillary column thus appears to be the simplest means to simultaneously and accurately quantitate petroselinic, oleic andcis‐vaccenic acids.