Trans-esterification of fatty acids from microorganisms and human blood serum by trimethylsulfonium hydroxide (TMSH) for GC analysis

Müller, Karl-Dieter; Husmann, H.; Nalik, H. P.; Schomburg, G.

doi:10.1007/bf02319701

Cited by 65 publications

(44 citation statements)

References 4 publications

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“…In the pyrolytic reaction of fatty acid ethanolamides (1) with TMSH substantial proportions of O-methyl derivatives (2) were formed, and it is obvious that methylation of the primary hydroxy group is the preferred reaction. The O-methyl derivative (2) is then utilized for the methylation of the secondary amide group leading to N,O-dimethyl fatty acid ethanolamides (4). A less important sequence of reactions may lead first to the N-methyl derivative (3), which is finally O-methylated to the N,O-dimethyl derivative (4).…”

Section: Fatty Acid Ethanolamidesmentioning

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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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: Fatty Acid Ethanolamidesmentioning

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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“…The bacteria were grown on R2A Agar at 281C for 24 h. Lysis of bacteria and transesterification of the FAs were carried out in a rapid single step, according to Müller et al [14]. Briefly, a few colonies of bacteria were harvested and suspended in 10 mL of distilled water, and then 30 mL of methanolic trimethylsulfonium hydroxide solution (0.25 M) were added.…”

Section: Sample Preparationmentioning

confidence: 99%

“…A single-step, rapid methylation procedure (2-3 min), using a trimethylsulfonium hydroxide methanol solution, was employed [14], followed by a relatively rapid GC Â GC-MS analysis.…”

Section: Giorgia Purcaromentioning

confidence: 99%

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Characterization of bacterial lipid profiles by using rapid sample preparation and fast comprehensive two‐dimensional gas chromatography in combination with mass spectrometry

Purcaro

Tranchida

Dugo

et al. 2010

J of Separation Science

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The bacteria fatty acid profile has been extensively studied for taxonomic classification purposes, since bacteria, in general, contain particular and rare fatty acids, compared with animal and plant tissues. As for any real-world sample type, the development of rapid and reliable methods for (i) sample identification (in this case, bacterium type), and (ii) constituent identification (in this instance, the fatty acid profile) is desirable. In this research, a half-an-hour procedure, to analyze bacteria, was developed: a 2-min one-step sample preparation step was followed by a relatively fast comprehensive 2D GC-MS separation (25 min). Furthermore, dedicated MS libraries were constructed for the identification of bacteria and fatty acids. Finally, data processing, only qualitative at this stage, was carried out with the support of a novel comprehensive 2D GC software.

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“…The dried extract was dissolved in 1 ml of methanol, mixed with 1 ml of 50 mM HCl-Tris [tris(hydroxymethyl)aminomethane] buffer (pH 7.4, containing 1 mg of calcium chloride and 1,500 units of phosphaolipase A 2 (from honey bee venom; Sigma, St. Louis, MO), and incubated for 2 h at room temperature (25). After centrifugation at 1,000 g for 5 min at 4°C, the lower chloroform layer was collected and dried by N 2 gas.…”

Section: Structural Determination Of Plpcooh Isomersmentioning

confidence: 99%

Preparation of pure lipid hydroperoxides

Ibusuki

Nakagawa

Asai

et al. 2008

Journal of Lipid Research

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Increasing evidence of lipid peroxidation in food deterioration and pathophysiology of diseases have revealed the need for a pure lipid hydroperoxide (LOOH) reference as an authentic standard for quantification and as a compound for biological studies in this field. Generally, LOOH is prepared from photo-or enzymatically oxidized lipids; however, separating LOOH from other oxidation products and preparing pure LOOH is difficult. Early studies showed the usability of reaction between hydroperoxide and vinyl ether for preparation of pure LOOH. Because the reactivity of vinyl ether with LOOHs other than fatty acid hydroperoxides has never been reported, here, we employed the reaction for preparation of a wide variety of pure LOOHs. Phospholipid, cholesteryl ester, triacylglycerol, or fatty acid was photo-or enzymatically oxidized; the resultant crude sample containing hydroperoxide was allowed to react with a vinyl ether [2-methoxypropene (MxP)]. Liquid chromatography (LC) and mass spectrometry confirmed that MxP selectively reacts with LOOH, yielding a stable MxP adduct (perketal). The lipophilic perketal was eluted at a position away from that of intact LOOH and identified and isolated by LC. Upon treatment with acid, perketal released the original LOOH, which was finally purified by LC. Using our optimized purification procedures, for instance, we produced 75 mg of pure phosphatidylcholine hydroperoxide (.99%) from 100 mg of phosphatidylcholine. Our developed method expands the concept of the perketal method, which provides pure LOOH references. The LOOHs prepared by the perketal method would be used as "gold standards" in LOOH methodology. Because lipid peroxidation is involved in food deterioration (1) and pathophysiology of human diseases (2, 3), there has been a great interest in the accurate measurement of lipid hydroperoxide (LOOH) concentration. This can be performed by several quantitative methods (4-11), and the most sensitive and reliable one is chemiluminescence detection-liquid chromatography (CL-LC) (9-11). Since there is no approved LOOH calibrator ("gold standard") available, it is impossible to compare the LOOH levels from various laboratories around the world.Currently, researchers prepare their own in-house reference LOOH [i.e., lipids (e.g., phospholipids, cholesterols, triacylglycerols, and fatty acids)] are subjected to photo-(12), free radical (13), or enzymatic oxidation (14, 15). The resultant crude or partly purified LOOH is generally used as a calibrator. However, these references are neither officially approved nor do they correspond to each other, particularly with regard to their purity. As frequently mentioned by LOOH researchers, this problem is mainly caused by the difficulty in distinguishing and isolating LOOH from other oxidation products such as hydroxides (13). Therefore, efficient purification of a wide variety of LOOHs is the key to the development of the gold standard not only for the accurate quantification of LOOH but also for the evaluation of its biological fu...

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Trans-esterification of fatty acids from microorganisms and human blood serum by trimethylsulfonium hydroxide (TMSH) for GC analysis

Cited by 65 publications

References 4 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

Characterization of bacterial lipid profiles by using rapid sample preparation and fast comprehensive two‐dimensional gas chromatography in combination with mass spectrometry

Preparation of pure lipid hydroperoxides

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