著者

Shimba Kawasue Yohei Sakaguchi Reiko Koga Tadashi Hayama Hideyuki Yoshida Hitoshi Nohta

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.70, no.1, pp.19-24, 2022-01-01 (Released:2022-01-01)

参考文献数

30

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Casein is one of the allergen proteins present in milk. Therefore, a quantification method for the selective analysis of casein using fluorous derivatization with LC-tandem mass spectrometry (LC-MS/MS) was developed. After two allergen proteins (αS1-casein and β-casein) extracted from baked sugar cookies were tryptic digested, the obtained phosphorylated peptides were selectively derivatized by β-elimination with Ba(NO3)2 under basic condition and Michael addition with perfluoroalkylthiol (1H,1H,2H,2H-perfluorooctanethiol, PFOT). In this study, YKVPQLEIVPN(pSer)AQQR (104–119 fragment from αS1-casein) and FQ(pSer)EEQQQTEDELQDK (33–48 fragment from β-casein) obtained by tryptic digestion were selected as target peptides. The phosphorylated serine residue in each peptide was converted to a perfluoroalkyl group by derivatization. The obtained fluorous-derivatized peptides were analyzed by LC-MS/MS, to which a fluorous LC column was connected. Therefore, it was possible to analyze casein without being affected by the matrix components in the baked food sample. When the present method was applied to cookies with arbitrary amounts of αS1-casein and β-casein, the obtained quantification values were in good agreement with the arbitrary amounts spiked. The quantification limits of αS1- and β-casein in cookie analysis were 246 and 152 ng/g, respectively. Hence, this method can be used to analyze trace amounts of allergen proteins present in the baked food.

著者

Kenji HAMASE Yusuke NAKAUCHI Yurika MIYOSHI Reiko KOGA Nao KUSANO Hirohisa ONIGAHARA Hiroshi NARAOKA Hajime MITA Yasuhiko KADOTA Yasuhiro NISHIO Masashi MITA Wolfgang LINDNER

出版者

クロマトグラフィー科学会

雑誌

CHROMATOGRAPHY (ISSN:13428284)

巻号頁・発行日

vol.35, no.2, pp.103-110, 2014-08-10 (Released:2014-08-26)

参考文献数

39

被引用文献数

4 33

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A two-dimensional chiral high-performance liquid chromatographic (2D-HPLC) system has been established for the analysis of extraterrestrial amino acids. As the targets, 8 chiral amino acids (alanine (Ala), valine (Val), 2-aminobutyric acid (2AB), norvaline (nVal), N-methylalanine (N-MeAla), isovaline (iVal), 3AB and 3-aminoisobutyric acid (3AIB)) and 5 non-chiral amino acids (glycine (Gly), β-Ala, γ-aminobutyric acid (GABA), sarcosine (Sar) and 2AIB) were selected. These amino acids were tagged with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), and non-enantioselectively separated by a capillary monolithic ODS column in the first dimension. The target fractions were automatically introduced into the second dimension and further separated by Pirkle-type enantioselective columns. By using this system, the 2D-HPLC separation of 21 components in small particles of a carbonaceous chondrite (Yamato 791191, Antarctic CM2 meteorite) could be successfully performed, and all of the target amino acids were observed. The D/L ratios of the chiral molecules are almost 50/50 for all of the tested proteinogenic and non-proteinogenic amino acids.