title: Monitoring the synthetic reaction of a polyamide/peptide conjugate using electrospray ionization mass spectrometry.
abstract: Recently, the chemical structures of a series of monoimidazole/polyamine conjugates were studied in this laboratory using electrospray ionization mass spectrometry (ESI-MS) combined with tandem mass spectrometry (ESI-MS/MS). The method was found to be a powerful tool for the identification of this class of compounds. During the synthesis of targeted polyamide/peptide conjugates as derivatives or analogues of netropsin and distamycin, the method was applied to analyze and track the coupling reaction for the formation of the polyamide, which was difficult to achieve using thin layer chromatography (TLC). Characteristic fragmentation pathways for a nitro-monoimidazole conjugate, an amino-monoimidazole conjugate, and the final product (a nitro-diimidazole conjugate) were explored. The fragmentations of these conjugates were strongly affected by the presence of an amino group instead of a nitro group in the molecule, and led to the identification of the three compounds in the reacting solution or in the final reaction mixture. Consequently, the reaction could be monitored successfully and the synthetic route optimized.
authors.affiliation: Key Laboratory for Bioorganic Phosphorus Chemistry of Ministry of Education, Department of Chemistry, School of Life Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Changjin
authors.initials: C
authors.lastname: Zhu
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yang
authors.forename: Shuxia
authors.initials: S
authors.lastname: Cao
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Gu
authors.initials: G
authors.lastname: Yuan
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D008956:Models, Chemical; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D010455:Peptides; D011073:Polyamines