title: Supramolecular Adducts of Cucurbit[7]uril and Amino Acids in the Gas Phase.
abstract: The complexation of the macrocyclic cavitand cucurbit[7]uril (Q7) with a series of amino acids (AA) with different side chains (Asp, Asn, Gln, Ser, Ala, Val, and Ile) is investigated by ESI-MS techniques. The 1:1 [Q7 + AA + 2H](2+) adducts are observed as the base peak when equimolar Q7:AA solutions are electrosprayed, whereas the 1:2 [Q7 + 2AA + 2H](2+) dications are dominant when an excess of the amino acid is used. A combination of ion mobility mass spectrometry (IM-MS) and DFT calculations of the 1:1 [Q7 + AA + 2H](2+) (AA = Tyr, Val, and Ser) adducts is also reported and proven to be unsuccessful at discriminating between exclusion or inclusion-type conformations in the gas phase. Collision induced dissociation (CID) revealed that the preferred dissociation pathways of the 1:1 [Q7 + AA + 2H](2+) dications are strongly influenced by the identity of the amino acid side chain, whereas ion molecule reactions towards N-butylmethylamine displayed a common reactivity pattern comprising AA displacement. Special emphasis is given on the differences between the gas-phase behavior of the supramolecular adducts with amino acids (AA = Asp, Asn, Gln, Ser, Ala, Val, and Ile) and those featuring basic (Lys and Arg) and aromatic (Tyr and Phe) side chains.
authors.affiliation: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Pr. Lavrentieva 3, 630090, Novosibirsk, Russia. maikatnsk@gmail.com.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Kovalenko
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Vilaseca
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028, Barcelona, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Díaz-Lobo
authors.affiliation: Kazan National Research Technological University, 420015, K.Marx St 68, Kazan, Russia.
authors.forename: A N
authors.initials: AN
authors.lastname: Masliy
authors.affiliation: Serveis Centrals d'Instrumentació Científica, Universitat Jaume I, Avda. Sos Baynat s/n, E-12071, Castelló, Spain. barrera@sg.uji.es.
authors.forename: Cristian
authors.initials: C
authors.lastname: Vicent
authors.affiliation: Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Pr. Lavrentieva 3, 630090, Novosibirsk, Russia. cluster@niic.nsc.ru.
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Fedin
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D008956:Models, Chemical; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D000596:Amino Acids; D001952:Bridged-Ring Compounds; D005740:Gases; D007093:Imidazoles; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
keywords: Amino acid; Cucurbituril; Gas-phase studies; Supramolecular chemistry