Conformational Analysis and Intramolecular Interactions of L-Proline Methyl Ester and Its N-Acetylated Derivative through Spectroscopic and Theoretical Studies

Autor(es)

Braga, Carolyne B. ^[1] ; Ducati, Lucas C. ^[2] ; Tormena, Claudio F. ^[1] ; Rittner, Roberto ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, Phys Organ Chem Lab, BR-13083970 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Inst Chem, BR-05513970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry A; v. 118, n. 9, p. 1748-1758, MAR 6 2014.
• Citações Web of Science: 15

Resumo

This work reports a detailed study regarding the conformational preferences of L-proline methyl ester (ProOMe) and its N-acetylated derivative (AcProOMe) to elucidate the effects that rule their behaviors, through nuclear magnetic resonance (NMR) and infrared (IR) spectroscopies combined with 00113 theoretical calculations. These compounds do not present a zwitterionic form in solution, simulating properly amino acid residues in biological media, in a way closer than amino acids in the gas phase. Experimental (3)J(HH) coupling constants and infrared data showed excellent agreement with theoretical calculations, indicating no variations in conformer populations on changing solvents. Natural bond orbital (NBO) results showed that hyperconjugative interactions are responsible for the higher stability of the most populated conformer of ProOMe, whereas for AcProOMe both hyperconjugative and steric effects rule its conformational equilibrium. (AU)

• Processo FAPESP: 12/18567-4 - Investigação conformacional e das interações intramoleculares de derivados de aminoácidos utilizando as espectroscopias de RMN e IV e cálculos teóricos
• Beneficiário: Carolyne Brustolin Braga
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/03933-5 - Equilíbrios conformacionais e interações intramoleculares em uma série de aminoácidos: abordagem teórica e experimental
• Beneficiário: Roberto Rittner Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular