title: Antiplasmodial drugs in the gas phase: a CID and DFT study of quinolon-4(1H)-imine derivatives.
abstract: The gas-phase behavior of 12 quinolon-4(1H)-imine derivatives with antiplasmodial activity was investigated using electrospray ionization tandem mass spectrometry together with collision induced dissociation and density functional theory (DFT) calculations. The most probable protonation site was predicted by calculating the proton affinity (PA) values for each possible protonation site and it was found to be the imine nitrogen for all compounds under study. Fragmentation pathways of the protonated molecules were proposed and the assignment of product ion structures was performed taking into account theoretical calculations. The nature of the quinoline substituent was found to influence the gas-phase behavior of the compounds under study. The data acquired allowed to bracket the proton affinity of the quinolin-4-imine scaffold, which can be a useful starting point to choose appropriate references for determining PA values of this scaffold.
authors.affiliation: Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003, Lisbon, Portugal, pjamadeira@ff.ul.pt.
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Amorim Madeira
authors.forename: Ana Raquel Fernandes
authors.initials: AR
authors.lastname: Sitoe
authors.forename: Daniel
authors.initials: D
authors.lastname: Gonçalves
authors.forename: Tiago
authors.initials: T
authors.lastname: Rodrigues
authors.forename: Rita C
authors.initials: RC
authors.lastname: Guedes
authors.forename: Francisca
authors.initials: F
authors.lastname: Lopes
authors.forename: Rui
authors.initials: R
authors.lastname: Moreira
authors.forename: M Rosário
authors.initials: MR
authors.lastname: Bronze