TY - JOUR
T1 - Mass spectrometric discrimination of squalene monohydroperoxide isomers
AU - Shimizu, Naoki
AU - Bersabe, Hannah
AU - Ito, Junya
AU - Kato, Shunji
AU - Towada, Ryo
AU - Eitsuka, Takahiro
AU - Kuwahara, Shigefumi
AU - Miyazawa, Teruo
AU - Nakagawa, Kiyotaka
N1 - Funding Information:
This work was supported in part by Grants-in-Aid for Scientific Research(KAKENHI, 15H04497)of the Japan Society for the Promotion of Science(JSPS), Japan.
Publisher Copyright:
© 2017 by Japan Oil Chemists’ Society.
PY - 2017
Y1 - 2017
N2 - Squalene (SQ), a main component of human sebum, is readily photooxidized by exposure to sunlight, producing six squalene monohydroperoxide (SQ-OOH) isomers. Despite its known connection to various skin conditions, few studies have sought to analyze SQ-OOH at the isomeric level. In this study, we aimed to develop a method to discriminate each SQ-OOH isomer with the use of tandem mass spectrometry (MS/MS). The six standard SQ-OOH isomers were prepared by photooxidizing SQ in the presence of rose bengal, a photosensitizer, and isolated by semipreparative high-performance liquid chromatography (HPLC). To purify each isomer, 2-methoxypropene, which reversibly reacts with the hydroperoxide group of SQ-OOH, was utilized. Product ion scanning was then performed on the standard SQ-OOH isomers in the absence and presence of the sodium ion. In the absence of the sodium ion, the fragmentation patterns produced by atmospheric pressure chemical ionization were similar between the isomers, whereas in the presence of the sodium ion by electrospray ionization, unique fragmentation patterns were achieved. Based on these fragment ions, HPLC-MS/MS multiple reaction monitoring analysis was conducted on a mixture of the standard SQ-OOH isomers. We achieved discrimination of SQ-OOH isomers with high selectivity and detected SQ-OOH isomers at nanogram levels. These results may improve our understanding of the effect of SQ-OOH on skin conditions as well as the mechanism behind SQ peroxidation.
AB - Squalene (SQ), a main component of human sebum, is readily photooxidized by exposure to sunlight, producing six squalene monohydroperoxide (SQ-OOH) isomers. Despite its known connection to various skin conditions, few studies have sought to analyze SQ-OOH at the isomeric level. In this study, we aimed to develop a method to discriminate each SQ-OOH isomer with the use of tandem mass spectrometry (MS/MS). The six standard SQ-OOH isomers were prepared by photooxidizing SQ in the presence of rose bengal, a photosensitizer, and isolated by semipreparative high-performance liquid chromatography (HPLC). To purify each isomer, 2-methoxypropene, which reversibly reacts with the hydroperoxide group of SQ-OOH, was utilized. Product ion scanning was then performed on the standard SQ-OOH isomers in the absence and presence of the sodium ion. In the absence of the sodium ion, the fragmentation patterns produced by atmospheric pressure chemical ionization were similar between the isomers, whereas in the presence of the sodium ion by electrospray ionization, unique fragmentation patterns were achieved. Based on these fragment ions, HPLC-MS/MS multiple reaction monitoring analysis was conducted on a mixture of the standard SQ-OOH isomers. We achieved discrimination of SQ-OOH isomers with high selectivity and detected SQ-OOH isomers at nanogram levels. These results may improve our understanding of the effect of SQ-OOH on skin conditions as well as the mechanism behind SQ peroxidation.
KW - Mass spectrometry
KW - Squalene
KW - Squalene monohydroperoxide isomers
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U2 - 10.5650/jos.ess16159
DO - 10.5650/jos.ess16159
M3 - Article
C2 - 28190805
AN - SCOPUS:85014114096
VL - 66
SP - 227
EP - 234
JO - Journal of Oleo Science
JF - Journal of Oleo Science
SN - 1345-8957
IS - 3
ER -