Maoka Takashi, Fujiwara Yasuhiro, Hashimoto Keiji, Akimoto Naoshige
Research Institute for Production Development, Kyoto 606-0805, Japan.
Lipids. 2004 Feb;39(2):179-83. doi: 10.1007/s11745-004-1217-3.
The characterization and structure of epoxy carotenoids possessing 5,6-epoxy, 5,8-epoxy and 3,6-epoxy end groups conjugated to the polyene chain were investigated using high-energy fast atom bombardment collision-induced dissociation MS/MS methods. In addition to M - 80, a characteristic fragment ion of an epoxy carotenoid, product ions resulting from the cleavage of C-C bonds in the polyene chain from the epoxy end group, such as m/z 181 (b ion) and 121 (c ion), were detected. On the other hand, diagnostic ions of m/z 286 (e-H ion) and 312 (f-H ion) were observed, not in the 5,6-epoxy or 5,8-epoxy carotenoid but in the 3,6-epoxy carotenoid. These fragmentation patterns can be used to distinguish 3,6-epoxy carotenoids from 5,6-epoxy or 5,8-epoxy carotenoids. The structure of an epoxy carotenoid, 3,6-epoxy-5,6-dihydro-7',8'-didehydro-beta,beta-carotene-5,3'-diol (8), isolated from oyster, was characterized using FAB CID-MS/MS by comparing fragmentation patterns with those of related known compounds.
利用高能快原子轰击碰撞诱导解离质谱/质谱方法，对具有与多烯链共轭的5,6-环氧、5,8-环氧和3,6-环氧端基的环氧类胡萝卜素的表征和结构进行了研究。除了环氧类胡萝卜素的特征性碎片离子M - 80外，还检测到了由环氧端基处多烯链中碳-碳键断裂产生的产物离子，如m/z 181（b离子）和121（c离子）。另一方面，m/z 286（e-H离子）和312（f-H离子）的诊断离子不是在5,6-环氧或5,8-环氧类胡萝卜素中观察到，而是在3,6-环氧类胡萝卜素中观察到。这些碎裂模式可用于区分3,6-环氧类胡萝卜素与5,6-环氧或5,8-环氧类胡萝卜素。从牡蛎中分离出的一种环氧类胡萝卜素，3,6-环氧-5,6-二氢-7',8'-二脱氢-β,β-胡萝卜素-5,3'-二醇（8）的结构，通过将碎裂模式与相关已知化合物的模式进行比较，利用快原子轰击碰撞诱导解离质谱/质谱进行了表征。
