Negative electrospray ionization low-energy tandem mass spectrometry of hydroxylated fatty acids: a mechanistic study.

摘要: Recently, we reported that by converting olefinic fatty acids to their saturated vicinally 1,2-di-hydroxylated derivatives, abundant ions indicative for hydroxyl group locations are produced negative electrospray ionization low-energy tandem mass spectrometry, allowing the assignment of site in native acid. In this report mechanisms whereby characteristic investigated. The mono-hydroxylated acid, 12-hydroxyoctadecanoic served as a model more complex 12,13-dihydroxyoctadecanoic and fragmentation accounting most product generated from deprotonated molecules proposed. general, three different proposed operate formation observed ions: (i) step-wise charge-remote homolytic cleavages, (ii) charge-proximate (iii) concerted charge-directed rearrangement reactions involving bond formation(s) heterolytic cleavages. Support was achieved investigating deuterium- oxygen-18-labeled isotopomers both compounds.