Related Experiment Video
Updated: Jun 20, 2026

Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Discrimination of cyclic peptide diastereomers by electrospray ionization tandem mass spectrometry
Bo Zheng1, Yiquan Liu, Huihui Li
1Beijing 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.
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.
Related Concept Videos
Peptide Identification Using Tandem Mass Spectrometry
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
Tandem Mass Spectrometry
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
High-Resolution Mass Spectrometry (HRMS)
Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation
For example, the fragmentation of...
Chemical Ionization (CI) Mass Spectrometry

