Supramolecular Adducts of Cucurbit[7]uril and Amino Acids in the Gas Phase
Autor: | Vladimir P. Fedin, Cristian Vicent, A. N. Masliy, Marta Vilaseca, E. A. Kovalenko, Mireia Díaz-Lobo |
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Rok vydání: | 2015 |
Předmět: |
chemistry.chemical_classification
Bridged-Ring Compounds Spectrometry Mass Electrospray Ionization Collision-induced dissociation 010405 organic chemistry Stereochemistry Supramolecular chemistry Imidazoles Cavitand 010402 general chemistry 01 natural sciences Dissociation (chemistry) 0104 chemical sciences Adduct Amino acid chemistry Models Chemical Structural Biology Cucurbituril Side chain Gases Amino Acids Spectroscopy |
Zdroj: | Journal of the American Society for Mass Spectrometry. 27(2) |
ISSN: | 1879-1123 |
Popis: | 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. |
Databáze: | OpenAIRE |
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