Preparation of methyl esters of fatty acids with trimethylsulphonium hydroxide—an appraisal

El-Hamdy, Ali H.; Christie, William W.

doi:10.1016/0021-9673(93)80484-p

Cited by 24 publications

(19 citation statements)

References 9 publications

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“…TMSH is a powerful reagent for the preparation of fatty acid methyl esters by base-catalyzed transmethylation of acyl lipids, such as triacylglycerols [2][3][4][5]. Under pyrolytic conditions, fatty acid methyl esters are formed from free fatty acids by the reaction with TMSH as well [6].…”

Section: Resultsmentioning

confidence: 99%

“…Recently, a very convenient method has been described for the derivatization of acyl lipids to fatty acid methyl esters by using trimethylsulfonium hydroxide (TMSH) as the reagent [2][3][4][5]. This method is based on earlier publications, which have indicated the advantage of TMSH as a mild transmethylation reagent for the preparation of fatty acid methyl esters for GC analysis [6,7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Formation of N- and O-methyl derivatives of lipids containing amino, amide or hydroxy groups by the pyrolytic reaction with trimethylsulfonium hydroxide

Vosmann¹,

Schulte²,

Klein

et al. 1998

Fett/Lipid

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Base‐catalyzed transesterification of acyl lipids with methanol in the presence of trimethylsulfonium hydroxide (TMSH) is an easy and convenient method for the preparation of fatty acid methyl esters for GC analyses. However, lipids containing functional groups such as amino, amide and hydroxy groups are converted in varying degrees to the corresponding N‐ and O‐methyl derivatives by the pyrolytic reaction of TMSH occurring in the injector of the gas chromatograph. For example, lipids containing amino or amide groups are converted into the corresponding N‐methyl and N,N‐dimethyl derivatives, fatty acid ethanolamides to the corresponding N‐methyl, O‐methyl and N,O‐dimethyl derivatives, whereas alkyl methyl ethers are formed from long‐chain alcohols. Furthermore, 2‐O‐ and 3‐O‐monomethyl ethers as well as 2,3‐di‐O‐methyl ethers are formed from 1‐O‐alkylglycerols, methoxy fatty acid methyl esters from hydroxy fatty acids as well as steryl 3β‐O‐methyl ethers from cholesterol and other sterols. Since some of the mentioned artefacts may interfere with fatty acid methyl esters in GC separations the TMSH derivatization method is recommended only with caution for lipids containing amino, amide and hydroxy groups. The methylation reactions, which finally lead to the corresponding N‐methyl, O‐methyl, N,N‐dimethyl or N,O‐dimethyl derivatives of fatty acids and lipids may, however, be of some diagnostic value for the structural analysis of such lipids by GC/MS.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Formation of N- and O-methyl derivatives of lipids containing amino, amide or hydroxy groups by the pyrolytic reaction with trimethylsulfonium hydroxide

Vosmann¹,

Schulte²,

Klein

et al. 1998

Fett/Lipid

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show abstract

“…Base-catalyzed transesterification of O-acyl lipids using TMSH in the presence of methanol is a convenient method for the preparation of fatty acid methyl esters for GC analyses (3)(4)(5). S-Acyl lipids such as long-chain acyl thioesters are generally derivatized by acid-or alkali-catalyzed transmethylation leading to fatty acid methyl esters and alkanethiols (6).…”

Section: Resultsmentioning

confidence: 99%

“…Base-catalyzed transesterification of O-acyl lipids with methanol in the presence of TMSH is a convenient method for the preparation of fatty acid methyl esters for GC analyses (3)(4)(5). So far, this method has not been applied to the transesterification of S-acyl lipids (lipid thioesters), which are common constituents of microorganisms, plants, and animals (6).…”

mentioning

confidence: 99%

Simultaneous derivatization of acyl and S‐alkyl moieties of acyl thioesters by using trimethylsulfonium hydroxide for gas chromatographic analysis

Klein¹,

Weber²

2000

Lipids

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The reaction of long-chain acyl thioesters, viz. lauric acid dodecyl thioester, 1,8-di-S-palmitoyl octanedithiol, and tristearoyl alpha-monothioglycerol, with trimethylsulfonium hydroxide in the presence of methanol leads to simultaneous derivatization of acyl moieties and S-alkyl moieties of acyl thioesters to the corresponding fatty acid methyl esters and methyl alkylsulfides, respectively. These derivatized products were analyzed by gas chromatographic technique.

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“…Methodologies for the determination of oil expressed as FA in oilseeds usually include isolation of the lipids by solvent extraction (1)(2)(3), followed by chemical derivatization of the lipid sample to form FAME (4)(5)(6)(7). These classical extraction and methylation methodologies are laborious and consume large volumes of hazardous organic solvent, such as petroleum ether, hexane, and chloroform.…”

mentioning

confidence: 99%

The use of immobilized Candida antarctica lipase for simultaneous supercritical fluid extraction and in‐situ methanolysis of cis‐vaccenic acid in milkweed seeds

Turner

McKeon

2002

J Americ Oil Chem Soc

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cis-Vaccenate was determined in milkweed (Asclepias) seeds employing supercritical fluid extraction (SFE) with in-situ enzymatic methanolysis. Candida antarctica lipase type B immobilized onto two different types of carrier materials-a hydrophobic polymer (Novozyme 435) and a silica-based material (NovoSample 40013)-was investigated. Several SFE parameters were investigated to find the optimal conditions, including extraction time, temperature, methanol concentration, and water level. It was shown that 90 min of dynamic extraction/reaction time was required, and that the optimal methanol and water concentrations differed for the two enzyme preparations studied. Overall, Novozyme 435 demonstrated the fastest reaction kinetics and consistently gave the highest vaccenate yields. The optimized methodology was applied on 15 species of milkweed seeds, giving an average recovery of 105 ± 7% when compared to results obtained using a conventional methodology. The average relative standard deviations were 8% for the enzyme-based method and 4% for the reference method. The proposed methodology was faster, was less laborious, and consumed less organic solvent than the reference method. Hence, SFE with in-situ enzymatic methanolysis is a promising methodology for the analysis of FA in oilseeds.

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Preparation of methyl esters of fatty acids with trimethylsulphonium hydroxide—an appraisal

Cited by 24 publications

References 9 publications

Formation of N- and O-methyl derivatives of lipids containing amino, amide or hydroxy groups by the pyrolytic reaction with trimethylsulfonium hydroxide

Formation of N- and O-methyl derivatives of lipids containing amino, amide or hydroxy groups by the pyrolytic reaction with trimethylsulfonium hydroxide

Simultaneous derivatization of acyl and S‐alkyl moieties of acyl thioesters by using trimethylsulfonium hydroxide for gas chromatographic analysis

The use of immobilized Candida antarctica lipase for simultaneous supercritical fluid extraction and in‐situ methanolysis of cis‐vaccenic acid in milkweed seeds

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