The effects of the physical environment on the molecular recognition of some aromatic amino esters (A = 3-(3,4)dihydroxyphenyl)alanine methyl ester (DOPAOMe), 3-(3,4)dihydroxyphenyl)alanine ethyl ester (DOPAOEt) and tryptophan ethyl ester (trpOEt)) by the flattened-cone 2,8,14,20- tetrakis(L-valinamido)[4]resorcinarene (1L) have been investigated in both the gas-phase by ESI-MS spectrometry and in CDCl3 solutions by 1H and 13C NMR spectroscopy. It is found that the non-covalent [1L·H·DOPAOMe]+ and [1L·H·DOPAOEt]+ complexes are stable in the gas-phase. The last one is stable in CDCl3 solutions as well, while [1L·H·trpOEt]+ is not. The formation of the stable [1L·H·DOPAOEt]+ complex in CDCl3 is not affected by the presence of traces of additives, like D2O, DCl or ethyl acetate, or by absorption on silica. APT-13C NMR analysis of [1L·H·DOPAOEt]+ suggests that the amino ester is mainly located inside the resorcinarene cavity, in conformity with the most stable structure arising from MC/MD simulations.
Gaseous- versus solution-phase recognition of some aromatic amino esters by 2,8,14,20-tetrakis(L-valinamido)[4]resorcinarene / Botta, Bruno; G., Delle Monache; Fraschetti, Caterina; Nevola, Laura; Deborah, Subissati; Speranza, Maurizio. - In: INTERNATIONAL JOURNAL OF MASS SPECTROMETRY. - ISSN 1387-3806. - STAMPA. - 267:1-3 SPEC. ISS.(2007), pp. 24-29. [10.1016/j.ijms.2007.02.015]
Gaseous- versus solution-phase recognition of some aromatic amino esters by 2,8,14,20-tetrakis(L-valinamido)[4]resorcinarene
BOTTA, Bruno;FRASCHETTI, CATERINA;NEVOLA, LAURA;SPERANZA, Maurizio
2007
Abstract
The effects of the physical environment on the molecular recognition of some aromatic amino esters (A = 3-(3,4)dihydroxyphenyl)alanine methyl ester (DOPAOMe), 3-(3,4)dihydroxyphenyl)alanine ethyl ester (DOPAOEt) and tryptophan ethyl ester (trpOEt)) by the flattened-cone 2,8,14,20- tetrakis(L-valinamido)[4]resorcinarene (1L) have been investigated in both the gas-phase by ESI-MS spectrometry and in CDCl3 solutions by 1H and 13C NMR spectroscopy. It is found that the non-covalent [1L·H·DOPAOMe]+ and [1L·H·DOPAOEt]+ complexes are stable in the gas-phase. The last one is stable in CDCl3 solutions as well, while [1L·H·trpOEt]+ is not. The formation of the stable [1L·H·DOPAOEt]+ complex in CDCl3 is not affected by the presence of traces of additives, like D2O, DCl or ethyl acetate, or by absorption on silica. APT-13C NMR analysis of [1L·H·DOPAOEt]+ suggests that the amino ester is mainly located inside the resorcinarene cavity, in conformity with the most stable structure arising from MC/MD simulations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.