title: MS/MS and LC-MS/MS analysis of choline/ethanolamine plasmalogens via promotion of alkali metal adduct formation.
abstract: Tandem mass spectrometry (MS/MS) has been used for the analysis of plasmalogen (Pls), a physiologically important class of vinyl ether-linked phospholipid. However, MS/MS generally causes little fragmentation of Pls, especially choline Pls (PC-Pls). Previous MS/MS studies reported an increased formation of product ions of PC-Pls (and also ethanolamine Pls (PE-Pls)) in the presence of 'alkali metals.' Therefore, use of alkali metals considerably leads to the development of a method for analysis of both PC- and PE-Pls. In this study, this notion was evaluated using quadrupole-time-of-flight MS/MS and liquid chromatography (LC) coupled with MS/MS. Results from MS/MS confirmed that alkali metals (e.g., sodium) produced significant fragmentation of PC-Pls and PE-Pls. A number of structure-diagnostic product ions exhibiting high intensities were observed under optimized MS/MS conditions using alkali metals. Moreover, the ability to selectively and sensitively identify PC-Pls and PE-Pls at the molecular species level in biological samples (rat brain and heart) was demonstrated using LC-MS/MS. Therefore, the herein developed method appears to be a powerful tool for analyzing Pls and may provide a better understanding of their physiological roles in vivo.
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
authors.forename: Yurika
authors.initials: Y
authors.lastname: Otoki
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan. Electronic address: nkgw@m.tohoku.ac.jp.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Kato
authors.affiliation: Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan; Food Biotechnology Innovation Project NICHe, Tohoku University, Sendai 980-8579, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Miyazawa
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D008297:Male; D008672:Metals, Alkali / Q000737:chemistry*; D009206:Myocardium / Q000378:metabolism; D010955:Plasmalogens / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D008672:Metals, Alkali; D010955:Plasmalogens; C032459:choline plasmalogens; C020791:phosphatidal ethanolamines
keywords: Choline plasmalogen; Ethanolamine plasmalogen; Plasmalogen; Rat tissues; Tandem mass spectrometry