title: Discrimination of cyclic peptide diastereomers by electrospray ionization tandem mass spectrometry.
abstract: In this research, the characteristic ions' abundance ratio between two isomers A and B in MS/MS mass spectra was defined as a parameter for discriminating diastereomers. Through this ratio, the discrimination of four pairs of cyclic peptide (CP) diastereomers was successfully achieved. Furthermore, in the analysis of diastereomers' mixtures, both calibration curve and calculational methods were substantiated to have high precision and accuracy. The average absolute errors of the two methods were 2.0 and 2.5% in the 48 measurements of 16 samples, respectively. This research provided a promising approach for the analysis of the CP diastereomers in the fields of asymmetrical synthesis, chiral natural products and structural biology by ESI-MS/MS.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zheng
authors.forename: Yiquan
authors.initials: Y
authors.lastname: Liu
authors.forename: Huihui
authors.initials: H
authors.lastname: Li
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Ye
authors.forename: Xingming
authors.initials: X
authors.lastname: Gao
authors.forename: Gu
authors.initials: G
authors.lastname: Yuan
mesh_terms: D004365:Drugs, Chinese Herbal / Q000737:chemistry; D010449:Peptide Mapping / Q000379:methods*; D010456:Peptides, Cyclic / Q000737:chemistry*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry
chemical_list: D004365:Drugs, Chinese Herbal; D010456:Peptides, Cyclic