Shibamoto Shigeaki, Murata Tasuku, Lu Wenjian, Yamamoto Kouhei
Shimadzu Corporation, 3-9-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto, 619-0237, Japan.
Shimadzu Corporation, 1, Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto, 604-8511, Japan.
Lipids. 2018 Jun;53(6):653-659. doi: 10.1002/lipd.12047. Epub 2018 Jul 10.
The dimethyl disulfide (DMDS) adduct method is one of the more effective methods for determining double bond positions of dienoic acid. The DMDS method can be simply used to obtain the characteristic ions in which cleavage occurs between the methylthio group-added double-bond carbons as can be seen in the mass spectrum obtained using gas chromatography/electron ionization-mass spectrometry. In the case of the methylene-interrupted di-cis type and di-trans type dienoic acid, the DMDS addition reaction only occurs at one double-bond position, and cannot occur at the remaining double-bond position due to steric hindrance. As a result, two types of adducts are produced in the addition reaction. However, in the case of the methylene-interrupted mono-trans (mono-cis) type dienoic acid, the DMDS addition reaction only occurs at the cis-double bond. As a result, one type of adduct is produced in the addition reaction. In this report, we investigate the cause of the reaction selectivity by focusing on the addition reaction time.
二甲基二硫醚（DMDS）加合物法是确定二烯酸双键位置的较为有效的方法之一。DMDS法可简单地用于获得特征离子，在使用气相色谱/电子电离质谱法获得的质谱图中，可以看到在添加甲硫基的双键碳之间发生裂解。对于亚甲基间断的二顺式和二反式二烯酸，DMDS加成反应仅在一个双键位置发生，由于空间位阻，在其余双键位置不会发生。结果，加成反应中产生两种加合物。然而，对于亚甲基间断的单反式（单顺式）二烯酸，DMDS加成反应仅在顺式双键处发生。结果，加成反应中产生一种加合物。在本报告中，我们通过关注加成反应时间来研究反应选择性的原因。
