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Comparison of electrospray ionization and atmospheric chemical ionization coupled with the liquid chromatography-tandem mass spectrometry for the analysis of cholesteryl esters.

Lee HR, Kochhar S, Shim SM - Int J Anal Chem (2015)

Bottom Line: The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI.RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length.The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Technology, Sejong University, 98 Gunja-dong, Seoul 143-747, Republic of Korea.

ABSTRACT
The approach of two different ionization techniques including electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was tested for the analysis of cholesteryl esters (CEs). The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI. RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length. The ESI process generated strong signal intensity of precursor ions corresponding to [M+Na](+) and [M+NH4](+) regardless of the number of carbon chains and double bonds in CEs. On the other hand, the APCI process produced a protonated ion of CEs [M+H](+) with a weak signal intensity, and it is selectively sensitive to detect precursor ions of CEs with unsaturated fatty acids. The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.

No MeSH data available.


Biosynthesis of cholesterol esters (CEs) in human by two enzymes: lecithin-cholesterol acyl transferase (LCAT) (a) and acyl-coA:cholesterol acyltransferase (ACAT) (b).
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fig1: Biosynthesis of cholesterol esters (CEs) in human by two enzymes: lecithin-cholesterol acyl transferase (LCAT) (a) and acyl-coA:cholesterol acyltransferase (ACAT) (b).

Mentions: Cholesteryl ester (CEs) is an esterified form of Chl in mother's milk and it consists of a long chain fatty acids, connecting with the hydroxyl group of Chl. It is known as an efficient form to transport Chl through the blood stream [7]. There are two enzymes involved in the biosynthesis of CEs in humans, that is, lecithin-cholesterol acyl transferase (LCAT) and acyl-coA:cholesterol acyltransferase (ACAT). LCAT catalyzes Chl to cholesteryl esters by transferring fatty acids to Chl. In the small intestine, absorbed Chl is esterified by ACAT (Figure 1) [7–10]. The biosynthesis of CEs plays a role in the regulation of cholesterol transport and storage as well as membrane function. More importantly, it is controlled by intracellular Chl levels [11].


Comparison of electrospray ionization and atmospheric chemical ionization coupled with the liquid chromatography-tandem mass spectrometry for the analysis of cholesteryl esters.

Lee HR, Kochhar S, Shim SM - Int J Anal Chem (2015)

Biosynthesis of cholesterol esters (CEs) in human by two enzymes: lecithin-cholesterol acyl transferase (LCAT) (a) and acyl-coA:cholesterol acyltransferase (ACAT) (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4383307&req=5

fig1: Biosynthesis of cholesterol esters (CEs) in human by two enzymes: lecithin-cholesterol acyl transferase (LCAT) (a) and acyl-coA:cholesterol acyltransferase (ACAT) (b).
Mentions: Cholesteryl ester (CEs) is an esterified form of Chl in mother's milk and it consists of a long chain fatty acids, connecting with the hydroxyl group of Chl. It is known as an efficient form to transport Chl through the blood stream [7]. There are two enzymes involved in the biosynthesis of CEs in humans, that is, lecithin-cholesterol acyl transferase (LCAT) and acyl-coA:cholesterol acyltransferase (ACAT). LCAT catalyzes Chl to cholesteryl esters by transferring fatty acids to Chl. In the small intestine, absorbed Chl is esterified by ACAT (Figure 1) [7–10]. The biosynthesis of CEs plays a role in the regulation of cholesterol transport and storage as well as membrane function. More importantly, it is controlled by intracellular Chl levels [11].

Bottom Line: The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI.RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length.The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Technology, Sejong University, 98 Gunja-dong, Seoul 143-747, Republic of Korea.

ABSTRACT
The approach of two different ionization techniques including electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was tested for the analysis of cholesteryl esters (CEs). The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI. RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length. The ESI process generated strong signal intensity of precursor ions corresponding to [M+Na](+) and [M+NH4](+) regardless of the number of carbon chains and double bonds in CEs. On the other hand, the APCI process produced a protonated ion of CEs [M+H](+) with a weak signal intensity, and it is selectively sensitive to detect precursor ions of CEs with unsaturated fatty acids. The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.

No MeSH data available.