Investigation of Noncovalent Complexes Between β-Cyclodextrin and Artemisinin by Electrospray Ionization Mass Spectrometry

To investigate the interactins of non-covalent complexes between beta-cyclodextrin and types of three artemisinis, electrospray ionization-time of flight mass spectrometry (ESI-TOF-MS) was used to detect equivolume mixtures of beta-cyclodextrin and artemisinins in positive ion mode. In this study, the samples were directly injected into electrospray ionization system. A method used of collision induced dissociation (CID) was applied for the study of their complexes. the results indicated that the non-covalent complexes can stably exist in gas phase, and the 1:1 and 2:1 binding modes were indicated by examining the binding stoichiometry from ESI mass spectra. With electrospray ionization-time of fight-mass spectrometry, the binding constants ( K) of the I: I inclusion complexes were determined respectively, and the parameters of mass spectrometry and solution system were optimized and investigated. By comparison of the K values, the interactions between beta-cyclodextrin and artemisinins in the gas phase were discussed.