The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalixarene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.
Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy-Tetraglucosylcalixarene / M. Torvinen; E. Kalenius; F. Sansone; A. Casnati; J. Jänis. - In: JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY. - ISSN 1044-0305. - 23(2012), pp. 359-365. [10.1007/s13361-011-0289-3]