Natural neo acids and neo alkanes: Their analogs and derivatives

This review presents more than 260 naturally occurring (as well as 47 synthesized) neo fatty (carboxylic) acids, neo alkanes, and their analogs and derivatives, isolated and identified from plants, algae, fungi, marine invertebrates, and microorganisms, that demonstrate different biological activities. These natural metabolites are good prospects for future chemical preparations as antioxidants, and also as anticancer, antimicrobial, and antibacterial agents. Described also are some synthetic bioactive compounds containing a tertiary butyl group(s) that have shown high anticancer, antifungal, and other activities. Applications of some neo fatty (carboxylic) acid derivatives in cosmetic, agronomic, and pharmaceutical industries also are considered. This is the first review to consider naturally occurring neo fatty (carboxylic) acids, neo alkanes, and other metabolites containing a tertiary butyl group(s) [or tert-butyl unit(s)].     

The genus Thapsia as a source of petroselinic acid

We describe the results from the isolation and structural identification of the acylglycerol constituents of fruits from wild plants belonging to different species of Thapsia (Apiaceae). The isolated lipid fractions were analyzed and characterized by chemical, chromatographic, and spectroscopic means. In particular, ¹³C nuclear magnetic resonance data allowed the identification of petroselinic acid as the major fatty acid esterified to glycerol in the fruit oils from all the plant samples. This was also confirmed by gas chromatography (GC) and GC-mass spectrometry analyses of fatty acid methyl and butyl esters derivatives from Thapsia oil. The genus Thapsia should be regarded as a useful source for the extraction of petroselinic acid, which represents an important oleochemical raw material.     

Dibutyrate derivatization of monoacylglycerols for the resolution of regioisomers of oleic, petroselinic, and cis-vaccenic acids

Dibutyrate derivatives of monoacylglycerols of oleic, petroselinic, and cis-vaccenic acids were prepared by diesterification of monoacylglycerols with n-butyryl chloride. The resulting triacylglycerols were analyzed by gas chromatography (GC) with a 65% phenyl methyl silicone capillary column and separated on the basis of both fatty acid composition and regiospecific position. The petroselinic acid derivatives eluted first, followed sequentially by the oleic and cis-vaccenic acid derivatives, with the sn−2 positional isomer eluting before the sn−1(3) isomer in each case. Separation of the peaks was almost baseline between petroselinic and oleic acids as well as between oleic and cis-vaccenic acids. To assess the accuracy of the method, mixtures of triolein, tripetroselinin, and tri-cis-vaccenin in various known proportions were partially deacylated with the use of ethyl magnesium bromide and derivatized and analyzed as above. The results showed that this method compares favorably to the existing methods for analysis of oleic, petroselinic, and cis-vaccenic fatty acids by GC with respect to peak separation and accuracy, and it also provides information on the regiospecific distribution of the fatty acids. The method was applied to basil (Ocimum basilicum) and coriander (Coriandrum sativum) seed oils. cis-Vaccenic, oleic, and linoleic acids were mainly distributed at the sn−2 position in basil seed oil, and higher proportions of linolenic, palmitic, and stearic acids were distributed at the sn−1(3) position than at the sn−2 position. In coriander seed oil, petroselinic acid was mainly distributed at the sn−1(3) position, and both oleic and linoleic acids were mostly located at the sn−2 position, whereas palmitic, stearic, and cis-vaccenic acids were located only at the sn−1(3) position.     

Fatty Acid Composition of Seeds From Wild and Cultivated Ginseng (Panax ginseng Meyer): Occurrence of a High Level of Petroselinic Acid

The lipid content and fatty acid (FA) composition of seeds from the Asian ginseng Panax ginseng growing naturally in taiga forests of the Russian Far East and seeds from cultivated ginseng were studied in this work. The total lipid content of seeds from both wild and cultivated plants was 9–12 % of fresh weight. FA were analyzed as isopropyl esters on a polar capillary column BD‐225, which allows good separation of petroselinic and oleic acids. The structure of FAs was confirmed using GC–MS of fatty acid methyl ester (FAME) and 4,4‐dimethyloxazoline derivatives. In all the seed samples, the major FA was petroselinic acid 18:1(n‐12) which comprised more than 60 %; the contents of oleic and linoleic acids were lower (15–17 and 15–16 %, respectively). Earlier, a higher level (>80 %) of oleic acid had been reported for ginseng seeds. This discrepancy can be explained by an insufficient separation of these acids on standard columns used for GC of FAME. In general, seeds of wild and cultivated ginseng are very similar in lipid content and FA composition.     

The synthesis,properties, and applications of ascorbyl esters

Ascorbic acid is a naturally occurring antioxidant. Nevertheless, its primary applications as an antioxidant in the life science, food and pharmaceutical industries are limited because of its hydrophilic nature. Alternatively, ascorbyl acid esters are potential surfactants and antioxidants. Chemical methods for the synthesis of ascorbyl esters lead to the formation of side products and simultaneous decomposition of ascorbic acid due to harsh reaction conditions. In contrast, lipases are used as regioselective and mild catalysts for the synthesis of ascorbyl esters. So far, various acyl donors namely, fatty acids, fatty acid alkyl esters, fatty acid vinyl esters and triacylglycerols have been explored for the synthesis of ascorbyl fatty esters. Other compounds such as L‐methyl lactate, bixin, phenyl butyric acid are also used as acyl donors. This article is focused on the recent developments of lipase‐catalyzed synthesis of ascorbyl esters, their antioxidant properties and applications.     

Low temperature solubilities of fatty acids in selected organic solvents

Summary A number of highly purified fatty acids have been prepared and their solubilities determined in six common organic solvents within the temperature range from 10° to −70°. The acids studied were palmitic, stearic, oleic, elaidic, petroselinic, petroselaidic, linoleic, stearolic, arachidic, eicosenoic, behenic, erucic, and brassidic. The solvents used were methanol, ethyl acetate, diethyl ether, acetone, toluene, and n-heptane, representing six different solvent types. A limited study was also made with a series of hydrocarbon solvents in order to note any effects of solvent structure on fatty acid solubility. Data are discussed with respect to their application in separating various fatty acid mixtures by low temperature crystallization. From a dissertation submitted by Doris Kolb to The Ohio State University in partial fulfillment of the requirements for the Ph.D. degree, August, 1953. This work was supported in part from funds granted by the Ohio State University Research Foundation to the university for aid in fundamental research.     

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.     

The fatty acid profiles – including petroselinic and cis-vaccenic acid – of different Umbelliferae seed oils

Different varieties of fennel, caraway, and coriander (3 fennel, 7 caraway, and 4 coriander varieties), which belong to the Umbelliferae family, were analyzed on oil and water content, subsequently the fatty acid profiles of the oils were determined by automated gas chromatography. Using fatty acid butyl esters a complete fatty acid profile including petroselinic and cis-vaccenic acid was obtained. Furthermore, the obtained fatty acid contents were compared to those cited in literature, which were determined using different analysis procedures.     

<Emphasis Type="Italic">Geranium sanguineum</Emphasis> (Geraniaceae) seed oil: A new source of petroselinic and vernolic acid

The occurrent of petroselinic acid (18∶1Δ6cis) in seed oils was believed to be limited to the Umbelliferae or Apiaceae, and a few other members of the Umbelliflorae. A major occurrence of petroselinic acid outside the Umbelliflorae must therefore be regarded as highly unusual and surprising. The seed oil of Geranium sanguineum, a member of the family Geraniaceae, has now been found to contain petroselinic and vernolic acids as major FA in its seed oil TAG. These unusual FA have not been reported previously as constituents of Geraniaceae seed oils. The structure and composition of the seed oil FA from G. sanguineum were determined by combined use of chromatographic (TLC, capillary GLC) and spectroscopic (IR, GC-MS) techniques. The double-bond position in petroselinic acid was located unambiguously by the characteristic mass fragmentation of its dimethyldisulfide (DMDS) adduct. The epoxy FA was identified as vernolic acid by co-chromatography and by the mass fragments formed during GC-MS of the products of the epoxy ring-opening reaction with BF₃ in methanol.     

Screening analysis of unknown seed oils

In the present paper, modern tools for the screening analysis of unknown seed oils have been reviewed. The known plant fatty acid structures have been divided into three groups (usual, unusual non-oxygenated, unusual oxygenated fatty acids) and examples for each class are presented. Moreover, the importance of chemotaxonomy for the screening analysis of some lipid components is discussed. The main part of the work is focussed on various aspects of preliminary seed oil analyses for the detection of unusual fatty acids and lipid classes and the analysis of fatty acid derivatives by gas chromatography and gas chromatography/mass spectrometry. Furthermore, some useful methods to obtain rapid information on the configuration of double bonds are cited. The paper concludes with a scheme for the detection of unusual fatty acids and lipid classes in seed oils.     

The preparation and properties of some nitrogen-containing derivatives of petroselinic acid

Petroselinonitrile was prepared by distilling the ammonolysis products of petroselinic acid over phosphorus pentoxide, and also from parsley seed oil without first isolating the petroselinic acid. A high-boiling antioxidant was employed during the reaction to control polymerization. The reaction by-products were segregated from the pure petroselinonitrile by urea complexing. Petroselinamide was obtained from petroselinic acid by the acidolysis of urea. Although it was not possible to reduce the petroselinonitrile by catalytic hydrogenation without affecting the ethylenic linkage or without producing a mixture of the primary, secondary, and tertiary amines, petroselinonitrile was converted to primary petroselinylmine in good yields by reduction with metallic sodium and alcohol in toluene. The hydrochloride and the acetyl derivative of the pure primary amine have also been prepared. Presented at the AOCS meeting in New Orleans, Louisiana, May 7–9, 1962. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S.D.A.     

Macro peroxide initiators based on autoxidized unsaturated plant oils: Block/graft copolymer conjugates for nanotechnology and biomedical applications

The autoxidation of unsaturated fatty acids and their esters is one of the most important reactions in food and biological systems. Autoxidation is a type of reaction between air oxygen and unsaturated plant oils. This reaction starts with a hydrogen abstraction on the methylene group adjacent double bond, leaving a radical onto the carbon atom. Molecular oxygen attacks this radical leading to produce peroxide and hydroperoxide derivatives of the oligomerized unsaturated plant oils. Because peroxide groups thermally cleave to produce free radicals, hydroperoxide derivatives of unsaturated plant oil oligomers can be used in the free radical polymerization of vinyl monomers leading to the related block/graft copolymers. The obtained copolymers combined with the biodegradable natural plant oil gain superior properties such as biodegradability and softness. In this review article, the in vitro autoxidation of well-known unsaturated plant oils-soybean oil, linseed oil, and castor oil and some related unsaturated fatty acids-oleic acid, linoleic acid, and ricinoleic acid was carried out under atmospheric conditions with or without exposing white light. Because the autoxidized unsaturated oil/fatty acids contain peroxide/hydroperoxide groups (they are referred to as macro peroxide initiators) that they are used in the free radical polymerization of vinyl monomers to obtain block/graft copolymers. The improved polymerization conditions, characterization, and applications of the obtained products will be discussed.     

Ketofettsäure-Derivate – Ein einfaches Verfahren zu ihrer Herstellung

Keto Fatty Acids – A Simple Procedure for their Preparation Derivatives of keto fatty acids are trace components in many of the naturally occurring oils and fats. After a survey of preparation procedures described in the literature, a simple possibility for the preparation of keto fatty acid derivatives by alkali- or alkaline earth iodides catalyzed rearrangement of epoxidized fatty acid derivatives will be presented. Tests of these compounds as additives in PVC processing showed positive results.     

Isolation of a Series of Fatty Acid Components of Ongokea gore Seed (Isano) Oil and their Detailed Structural Analysis

The total oil production capacity of isano oil is estimated at about 10,000 tons annually. Previous studies of this oil revealed that it is rich in fatty acids including a conjugated diyne moiety. This makes isano oil an excellent candidate for sustainable applications development. However, only a few of its fatty acids have been isolated and identified so far. In this study, we have reinvestigated this oil by characterizing its physicochemical properties and isolating several of its fatty acids as ethyl esters for their detailed structural analysis and identification. Six ethyl esters of fatty acids constituting isanic oil were isolated by flash column chromatography and semipreparative HPLC. The detailed structural analysis of these fatty acid esters by infrared, high resolution, mass spectroscopy, and nuclear magnetic resonance (1‐D and 2‐D) allowed determining unequivocally their chemical structure. The main fatty acid component of the oil (35.7 %) was identified as isanic acid. Four minor acids were found to possess also two conjugated triple bonds, while the sixth fatty acid does not contain carbon–carbon triple bonds nor double bonds but possessed a cis epoxide function. Results obtained in this study are currently being used to explore potential applications of isano oil.     

Antimicrobial activity of some ricinoleic acid oleic acid derivatives

Ricinoleic and acid oleic acid derivatives were screened for their antimicrobial activity, under optimum growing-conditions, against several species of bacteria, yeasts, and molds. Several ricinoleic acid derivatives and petroselinic (iso-oleic) acid exhibited considerable activity; in fact, their activity against some micro-organisms was comparable to sorbic and 10-undecenoic acid, known antimicrobial agents, as indicated by this test. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Hydriodic Acid Reduction of α-Ketol and α-Diketo Fatty Acids

The hydriodic acid reduction of α-ketol and α-diketo derivatives of three monoethenoid fatty acids, oleic, petroselinic and erucic acids, has been studied. The formation of an isomeric mixture of monoketo acids in each has been established by characterization of monocarboxylic or dicarboxylic acids, the hydrolysed fragments of Beckmann rearrangement of the corresponding oximes of monoketo acids, by thin-layer chromatography (TLC). Hydriodic acid has been found to be a satisfactory reagent for the synthesis of monoketo acids from the α-ketol and α-diketo acids.     

Dynamic Analysis of Phorbol Esters in the Manufacturing Process of Fatty Acid Methyl Esters from <Emphasis Type="Italic">Jatropha curcas</Emphasis> Seed Oil

Jatropha curcas seed oil, which is unsuitable as an edible oil but has received attention as a novel vegetable fat and oil resource, contains tumor-promoting phorbol esters. Currently, six types of derivatives of 12-deoxy-16-hydroxyphorbol (DHPEs) in J. curcas oil have been identified, and their toxicological safety for humans is being discussed. However, it is reported that most DHPEs disappear during the transesterification process. We investigated the dynamics of phorbol esters in the manufacturing process of fatty acid methyl esters from J. curcas seed oil. With the assumption that the precursor ion was the fragment ion (m/z = 311) from the frame unit of phorbol esters and their derivatives, we developed an LC–MS method for detecting the product ion (m/z = 165), which was obtained by cleavage of the fragment ion. The derivatives generated from the structural changes of the phorbol esters existed in fractions of glycerine–water in the manufacturing process; however, phorbol esters and their derivatives were not detected in the fatty acid methyl esters that were produced via a high-vacuum distillation process. Investigation into the dynamics of phorbol esters confirmed that the contents of phorbol esters, including DHPEs, in the fatty acid methyl esters were under detection limits.     

The chemistry of dibasic and polybasic fatty acids

Current processes to produce dibasic and polybasic fatty acids including azelaic, sebacic, dodecanedioic, C₂₁ diacid, fatty dimer and trimer acids are discussed. A number of alternative routes to produce azelaic, sebacic and fatty dimers are also discussed, includeding the preparation of azelaic and sebacic acids from butadiene and sebacic acid from adipic acid. Physical properties of the various dibasic acids are compared. Preparation of important derivatives and their applications is discussed, including: (a) esters and polyesters as vinyl plasticizers and as base stocks for synthetic lubricants; (b) polyamide resins in coatings, fibres, inks and adhesives; (c) salts as surfactants; and (d) amido amines and imidazolines as corrosion inhibitors. Dimer acids have found application in the petroleum industry as drilling mud thickeners in oil recovery.     

Search for new industrial oils: XVI. Umbelliflorae—seed oils rich in petroselinic acid

Seed oils of the order Umbelliflorae, including those from the families Umbelliferae, Garryaceae, Araliaceae, Cornaceae, Davidiaceae, Nyssaceae and Alangiaceae, were analyzed for fatty acid composition by gas liquid chromatography (GLC) of their methyl esters. The characteristic fatty acid of the order, petroselinic acid, occurred in the Umbelliferae in amounts up to 85%. In the Araliaceae, the content was as high as 83% and in the Garryaceae as high as 81%. The other major acids were palmitic, oleic and linoleic acids, with small amounts of hexadecenoic, stearic, linolenic, and, in some cases, C₂₀ acids. petroselinic acid was determined by microscale ozonolysis of the C₁₈ monoenoic esters and subsequent GLC of the ozonolysis products. The occurrence of high oil contents (up to 46%) combined with exceptionally high (up to 83%) single component purity is notable and emphasizes the potential of the Umbelliflorae as a raw material source for the chemical industry.     

New preparation of pure petroselinic acid from fennel oil (Foeniculum vulgare)

Pure petroselinic acid (cis-6-octadecenoic acid) has been isolated from fennel oil by acid soap crystallization at 4°C in methanol, followed by two urea segregations at room temperature and crystallization at −30°C in acetone. The purity control of petroselinic acid was effected by combined gas chromatography, and¹³C nuclear magnetic resonance. This petroselinic acid preparation was compared to other previous crystallization or enzymatic methods, showing that this method is both short (four steps) and easy to apply.