Some thermal properties of methyl malvalate, methyl sterculate, and their dihydro derivatives

White, J. L.; Zariņš, A.; Feuge, R. O.

doi:10.1007/bf02802030

Cited by 10 publications

(5 citation statements)

References 15 publications

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“…It is impossible for any homogeneous aqueous-organic or mixed organic mobile phase to achieve this range of interaction. Luminescence detection can be improved in PLC because many solutes show enhanced fluorescence (9,(12)(13)(14) and, in certain cases, room temperature liquid phosphorescence (9,10,15) when associated with micelles and cyclodextrins. In addition, many metal-dye complexes show increased absorbance in the presence of micelles (16).…”

Section: Resultsmentioning

confidence: 99%

“…The resulting methyl esters were subjected to a serie of urea clathrations and fractional crystallizations from methanol. The purification of the malvalate and sterculate concentrate was performed by a method similar to that described by White et al (14). The final purity of methyl malvalate and methyl sterculate was higher than 99%, as indicated by GLC at 150 °C on a BDS glass capillary column.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Determination of cyclopropenoic fatty acids by reversed-phase liquid chromatography and gas chromatography

Gaydou¹,

Bianchini²,

Ralaimanarivo³

1983

Anal. Chem.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Determination of cyclopropenoic fatty acids by reversed-phase liquid chromatography and gas chromatography

Gaydou¹,

Bianchini²,

Ralaimanarivo³

1983

Anal. Chem.

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“…Sterculic, dihydrosterculic, malvalic, and dihydromalvalic acids were obtained from Gordon Fisher of the Southern Regional Research Center, ARS, USDA, as the methyl esters and were originally isolated at that facility (38). trans-9,lO-Methyleneoctadecanoic acid, 9,10-epoxyoctadecanoic acid, phytanic acid, 2-hydroxytetradecanoic acid, 2-hydroxyhexacosanoic acid, and methyl 3-hydroxytetradecanoate were purchased from the Foxboro Co. (North Haven, CT).…”

Section: Methodsmentioning

confidence: 99%

Fast atom bombardment and tandem mass spectrometry for determining structural modification of fatty acids

Tomer¹,

Jensen²,

Gross³

1986

Anal. Chem.

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Previous studies showed that colllsionally activated gasphase carboxylate anlons of saturated fatty acids undergo losses of the elements of CH4, C2H6, C,H6, ... by way of a highly speclfk 1,4-eUmlnatbn of H, . These CnH2n+2 loses begln at the alkyl terminus and progress along the entire alkyl chaln. I n this paper we report that the presence of a substituent such as an alkyl branch, hydroxy group, cyclopropane rlng, cyclopropene ring, or epoxide rlng Interrupts this process in a characteristic fashlon that permits lndentlflcation of the substltuent and location of its position on the acid chaln. This method not only is useful for structural characterlzatlon of pure free fatty aclds but also Is applicable to the analysis of mixtures of carboxylic acids.Many lower forms of organisms such as bacteria, sponges, and certain plants possess the capability of producing a variety of structurally modified fatty acids. The structural modifications include branching, cyclopropane rings, cyclopropene rings, epoxy substituents, hydroxy and alkoxy groups, and unusual unsaturated acids. These acids are of interest because of their uniqueness and their utility for characterizing the organisms (1-5). Moreover, they may have substantial physiological implications for the organisms producing those substances and for organisms with which they come in contact.The problem of studying a specific fatty acid from a natural source is complicated because it must be isolated from a complex mixture of similar compounds. Classical methods of lipid analysis are described in several texts (4,6, 7). A wide range of techniques have been used for characterizing the purified compounds. They include comparison of chromatographic retention times with those of known compounds, degradative analysis, derivatization followed by analysis, synthesis of model compounds for comparison, and a variety of spectroscopic methods.Mass spectrometry has been especially useful for studying these compounds because pertinent structural information may be obtained from small samples, and gas chromatography/mass spectrometry (GC/MS) is an effective method for dealing with mixtures (8). The recent characterization of lipids of marine sponges by Djerassi and co-workers exemplifies the practical applicability of the method (ref 9 and 10 and references cited therein). Unfortunately, derivatization is necessary, as free acids are not amenable to GC/MS.A number of mass spectrometry methods have been applied to the study of structurally modified acids (11). Pioneering work in the field was done by Stenhagen and co-workers (12-16) who studied methyl esters of fatty acids by electron ionization (EI) mass spectrometry. Informative high mass ions are of low abundance and if double bonds are present, their location is obscured by rearrangments. Pyrrolidide (1 7-20) and more recently picolinyl derivatives of fatty acids (21-23) were established to be useful for locating the double bond position and other structural modifications. Chemical ionization (CI) mass spectrometry has been tip...

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“…AgNO 3 -chromatography is not suitable for the separation of cyclopropenoic fatty acids because of ring opening and other derivatization reactions catalyzed by silver ions (17,18). Methods used for the preparative isolation of cyclopropenoic fatty acids in good purity include repeated urea fractionations and crystallizations (9,19,20) as well as countercurrent distribution (19). We report here a simple method involving preparative RP-HPLC for the preparation of highly pure cyclopropenoic fatty acids, e.g., malvalic and sterculic acids, in appropriate quantities that could be of interest for chemical, biochemical, and analytical purposes.…”

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

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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...

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Some thermal properties of methyl malvalate, methyl sterculate, and their dihydro derivatives

Cited by 10 publications

References 15 publications

Determination of cyclopropenoic fatty acids by reversed-phase liquid chromatography and gas chromatography

Determination of cyclopropenoic fatty acids by reversed-phase liquid chromatography and gas chromatography

Fast atom bombardment and tandem mass spectrometry for determining structural modification of fatty acids

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

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