Revealing the Conformational Preferences of Proteinogenic Glutamic Acid Derivatives in Solution by H-1 NMR Spectroscopy and Theoretical Calculations

Author(s)

Siva, Weslley G. D. P. ^{[1, 2]} ; Tormena, Claudio F. ^[1] ; Rittner, Roberto ^[1]

Affiliation

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

^[2] Univ Manitoba, Dept Chem, Winnipeg, MB R3T 2N2 - Canada

• Document type: Journal article
• Source: Journal of Physical Chemistry A; v. 122, n. 18, p. 4555-4561, MAY 10 2018.
• Web of Science Citations: 2

Abstract

The conformational preferences of proteinogenic glutamic acid esterified (GluOMe) and N-acetylated (Ac-GluOMe) derivatives have been determined in solution for the first time. Theoretical calculations at the wB97X-D/aug-cc-pVTZ made possible the assignment of six and eight stable conformers for GluOMe and AcGluOMe, respectively. The conformational equilibrium of the studied compounds was evaluated in different organic solvents using a combination of the integral equation formalism polarizable continuum model (IEF-PCM) and H-1 NMR spectroscopy data. The results showed that the conformational equilibrium of both derivatives change in the presence of solvent. According to the quantum theory of atoms in molecules (QTAIM), non-covalent interactions (NCI), and natural bond orbitals (NBO) analyses, the conformational preferences observed for GluOMe and AcGluOMe are not dictated by the presence of a specific interaction but are due to a combination of hyperconjugative and steric effects. (AU)

• FAPESP's process: 16/24109-0 - Conformational Analysis of Some Aliphatic Esters Bearing a Nitrogen Atom as a Substituent
• Grantee: Roberto Rittner Neto
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/08541-6 - Nuclear magnetic resonance spectroscopy: beyond molecular structure assignment
• Grantee: Claudio Francisco Tormena
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/12005-5 - Conformational analyses of aminoacids derivatives: a theoretical and experimental approach
• Grantee: Weslley Guilherme Dias de Paiva Silva
• Support Opportunities: Scholarships in Brazil - Master