title: A novel rearrangement in electrospray ionization multistage tandem mass spectrometry of amino acid ester cyclohexyl phosphoramidates of AZT.
abstract: Several amino acid ester cyclohexyl phosphoramidates of AZT as anti-HIV prodrugs were synthesized and investigated by electrospray ionization tandem mass spectrometry (ESI-MS(n)). A novel methoxy group migration from the carbonyl group to the phosphoryl group was observed in ESI-MS2. This migration is believed to be a general pathway for ions with a methyl ester moiety at the gamma-position to a phosphoric acid moiety, which is assisted with metal ions such as Li(+), Na(+) and K(+). Coordination between metal ions with both the carbonyl oxygen and phosphoryl oxygen might be a key factor responsible for this migration.
authors.affiliation: Key Laboratory of Chemical Biology, Chemistry Department, Zhengzhou University, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Yingwu
authors.initials: Y
authors.lastname: Yin
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Sun
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000577:Amides / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D015394:Molecular Structure; D010756:Phosphoric Acids / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D000577:Amides; D000596:Amino Acids; D010756:Phosphoric Acids; D015215:Zidovudine; C011067:phosphoramidic acid