TY - JOUR
T1 - Chiral recognition in gas-phase cyclodextrin
T2 - amino acid complexes - Is the three point interaction still valid in the gas phase?
AU - Ahn, Seonghee
AU - Ramirez, Javier
AU - Grigorean, Gabriela
AU - Lebrilla, Carlito B
PY - 2001
Y1 - 2001
N2 - The validity of the 'three-point interaction' model is examined in the guest exchange reaction involving complexes of cyclodextrins and amino acids. The amino acid guest is exchanged in the gas phase in the presence of a gaseous alkyl amine. The net reaction is proton transfer between the protonated amino acid and the alkyl amine. The amino acid is lost as a neutral species. This reaction is sensitive to the chirality of the amino acid. Several amino acids are examined as well as the respective methyl esters to determine the role of the three interacting groups (ammonium, carboxylic acid, and side chain) in enantioselectivity. We find that the three-point interaction model is indeed valid in the gas phase. Enantioselectivity is optimal when two points of attraction and one repulsion is present in the gas-phase complex. The results are supported by molecular modeling calculations. A mechanism for the exchange is proposed.
AB - The validity of the 'three-point interaction' model is examined in the guest exchange reaction involving complexes of cyclodextrins and amino acids. The amino acid guest is exchanged in the gas phase in the presence of a gaseous alkyl amine. The net reaction is proton transfer between the protonated amino acid and the alkyl amine. The amino acid is lost as a neutral species. This reaction is sensitive to the chirality of the amino acid. Several amino acids are examined as well as the respective methyl esters to determine the role of the three interacting groups (ammonium, carboxylic acid, and side chain) in enantioselectivity. We find that the three-point interaction model is indeed valid in the gas phase. Enantioselectivity is optimal when two points of attraction and one repulsion is present in the gas-phase complex. The results are supported by molecular modeling calculations. A mechanism for the exchange is proposed.
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U2 - 10.1016/S1044-0305(00)00220-8
DO - 10.1016/S1044-0305(00)00220-8
M3 - Article
C2 - 11281603
AN - SCOPUS:0035567118
VL - 12
SP - 278
EP - 287
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
SN - 1044-0305
IS - 3
ER -