Cyclic fatty acids: Separation from straight‐chain fatty acids by urea adducting

Eisenhauer, R. A.; Beal, R. E.

doi:10.1007/bf02668964

Cited by 4 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Schofield and Cowan demonstrated that linolenic acid could be converted to a cyclized structure by heating in the presence of solvent and alkali (1). Subsequent papers have concerned themselves with methods for improving the preparation and yields of saturated cyclized product (2), its separation from straight chain fatty acids (3), determination by gas liquid chromatography (GLC) (4), and a structural study of these products as mixtures of the corresponding saturated and aromatic isomers (5). Extensive earlier structural work has been reviewed by Friedrich (5), including work on cyclic products from eleostearate.…”

Section: Introductionmentioning

confidence: 99%

Purification of cyclic fatty acid esters: a GC‐MS study

Perkins

Iwaoka

1973

J Americ Oil Chem Soc

View full text Add to dashboard Cite

Gas chromatographic analysis of cyclic monomeric concentrates and fractions from argentation chromatography on packed columns containing SE-30, OV-25 and Apiezon L stationary phases yielded incompletely separated peaks representing the various isomers present in the mixture. Somewhat better separation was achieved using a 6 flx I/8 in. column packed with 15% EGS on Chromosorb W. This column, when coupled to a mass spectrometer, yielded information concerning the composition of each of the isomeric components. Comparable results were obtained using a 50 ftx 0.02 in. S.C.O.T. column with DEGS stationary phase and a 150 ft x 0.01 in. capillary column coated with Apiezon L. While argentation thin layer chromatography proved useful, an argentation column method using silicic acid coated with 10% AgNO 3 proved more efficient for larger scale preparations. Elution of the column with 2% diethyl ether in petroleum ether yielded material essentially free of conjugated linolenate. A comparison of the behavior upon argentation thin layer chromatography of conjugated methyl linolenate, methyl linoleate and cyclic monomer esters

show abstract

Section: Introductionmentioning

confidence: 99%

Purification of cyclic fatty acid esters: a GC‐MS study

Perkins

Iwaoka

1973

J Americ Oil Chem Soc

View full text Add to dashboard Cite

show abstract

“…Pure cyclopropenoic fatty acids, such as malvalic and sterculic acids, which are of interest for lipid analysis as well as biochemical studies and chemical reactions, are not commercially available. Fractionation by urea adduct formation is known to yield concentrates of cyclopropenoic fatty acids together with unsaturated fatty acids (15). Separation of cyclopropenoic fatty acids by spinning band distillation requires relatively large proportions of starting material (16).…”

Section: Resultsmentioning

confidence: 99%

Preparation of malvalic and sterculic acid methyl esters from Bombax munguba and Sterculia foetida seed oils

Fehling¹,

Schönwiese²,

Klein³

et al. 1998

J Americ Oil Chem Soc

View full text Add to dashboard Cite

A method has been developed for the preparation of highly pure malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate-catalyzed transmethylation followed by cooling (6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by centrifugation in the case of B. munguba and by column chromatography in the case of S. foetida. Subsequently, the saturated straightchain fatty acid methyl esters were almost quantitatively removed by urea adduct formation. Finally, methyl malvalate and methyl sterculate were separated from the remaining unsaturated fatty acid methyl esters, in particular methyl oleate and methyl linoleate, by preparative high-performance liquid chromatography on C 18 reversed-phase using acetonitrile isocratically. Methyl malvalate and methyl sterculate were obtained with purities of 95-97 and 95-98%, respectively. JAOCS 75, 1757-1760 (1998). KEY WORDS:Bombax munguba oil, cyclopropene fatty acids, malvalic acid methyl ester, preparative HPLC, Sterculia foetida oil, sterculic acid methyl ester, urea fractionation.Cyclopropene fatty acids are widely distributed in the seed oils of many plant families of the order Malvales (1,2). Small proportions of cyclopropene fatty acids, e.g., malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acids, which are present in crude cottonseed oil, are of special interest owing to their harmful biological effects when fed to animals (3-7).The presence of cyclopropene fatty acids in seed oils can be roughly checked by the Halphen test (8). Identification by gas chromatography (GC) and high-performance liquid chromatography (HPLC) analysis (9,10) is difficult, however, because no cyclopropene fatty acid standards are commercially available. This paper presents a simple method for the preparation of both methyl malvalate and methyl sterculate of high purity, which may be useful for GC and HPLC comparison as well as biochemical and enzymatic studies. The starting materials were seeds of Bombax munguba (11) and Sterculia foetida (1,2), which are known to be good sources of cyclopropene fatty acids. EXPERIMENTAL PROCEDURESMaterials. Distilled solvents were used throughout. HPLCgrade acetonitrile was purchased from Rathburn Chemicals (Walkerburn, Scotland). Silica gel, urea, and sodium methylate were products of E. Merck (Darmstadt, Germany). Bombax munguba Mart. seeds were collected at University of Paraiba, João Pessoa, Brazil (11); S. foetida L. seeds were a gift from Professor Helmut K. Mangold, Münster, Germany.Preparation of fatty acid methyl esters (FAME). Seeds of B. munguba (10 g) were ground in an electric coffee grinder and the meal extracted in a Soxhlet extractor for 6 h with 200 mL hexane. The hexane was evaporated and the oil transmethylated with sodium methylate in methanol (11). After addition of...

show abstract

Carboxylic acids derived from Tasmanian tasmanite by extractions and kerogen oxidations

Simoneit

Burlingame

1973

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Cyclic fatty acids: Separation from straight‐chain fatty acids by urea adducting

Cited by 4 publications

References 2 publications

Purification of cyclic fatty acid esters: a GC‐MS study

Purification of cyclic fatty acid esters: a GC‐MS study

Preparation of malvalic and sterculic acid methyl esters from Bombax munguba and Sterculia foetida seed oils

Carboxylic acids derived from Tasmanian tasmanite by extractions and kerogen oxidations

Contact Info

Product

Resources

About