1H NMR and theoretical studies on the conformational equilibrium of tryptophan methyl ester

Duarte, Claudimar J.; Cormanich, Rodrigo A.; Ducati, Lucas C.; Rittner, Roberto

doi:10.1016/j.molstruc.2013.07.024

Cited by 8 publications

(12 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This solution was concentrated under reduced pressure to yield 484. 13 1 H NMR spectra were recorded on a Bruker Avance III spectrometer operating at 600 MHz for 1 H. Spectra were obtained for solutions of ca. 15 mg in 0.7 mL of different solvents (varying from C 6 D 6 to DMSO-d 6 , according to the solubility of the compound) with a probe temperature of 25°C, referenced to internal TMS.…”

Section: Experimental and Computational Detailsmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2014

Self Cite

View full text Add to dashboard Cite

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 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)JHH 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.

show abstract

Section: Experimental and Computational Detailsmentioning

confidence: 99%

“…12,13 These compounds do not exist as zwitterions in solution and are soluble in a majority of organic solvents, making possible their studies in solution by properly simulating the amino acid residues in biological media, better than amino acids in the gas phase.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…For a deeper understanding of amino acid properties, an interplay between theoretical and experimental methods is crucial. Consequently, high-level quantum chemical calculations, such as the Møller–Plesset (MP2) method and density functional theory (DFT) calculations, together with experimental techniques have been combined to achieve more accurate results [ 20 – 24 ].…”

Section: Introductionmentioning

confidence: 99%

“…Some amino acid derivatives have been recently studied by our research group, including the derivatives of tryptophan [ 20 ], phenylalanine and tyrosine [ 21 ], aspartic acid [ 22 ], proline [ 23 ] and histidine [ 24 ]. These studies have provided significant results to understand the importance of the corresponding amino acids in processes in which they take part in the polypeptide chain.…”

Section: Introductionmentioning

confidence: 99%

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and ³J_HH coupling constant analyses

Silva

Braga

Rittner

2017

Beilstein J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

The understanding of the conformational behavior of amino acids and their derivatives is a challenging task. Here, the conformational analysis of esterified and N-acetylated derivatives of L-methionine and L-cysteine using a combination of 1H NMR and electronic structure calculations is reported. The geometries and energies of the most stable conformers in isolated phase and taking into account the implicit solvent effects, according to the integral equation formalism polarizable continuum model (IEF−PCM), were obtained at the ωB97X-D/aug-cc-pVTZ level. The conformational preferences of the compounds in solution were also determined from experimental and theoretical 3 J HH coupling constants analysis in different aprotic solvents. The results showed that the conformational stability of the esterified derivatives is not very sensitive to solvent effects, whereas the conformational equilibrium of the N-acetylated derivatives changes in the presence of solvent. According to the natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM) and noncovalent interactions (NCI) methodologies, the conformational preferences for the compounds are not dictated by intramolecular hydrogen bonding, but by a joint contribution of hyperconjugative and steric effects.

show abstract

“…124 Esta molécula é extensivamente explorada por pesquisadores na área da espectroscopia devido às suas propriedades ópticas, como absorção UV e fluorescência, que ocorrem devido a presença de um anel indol em sua estrutura. Portanto, muitos estudos são dedicados à determinação estrutural do triptofano e seus derivados em solução [125][126][127] e em fase gasosa. 128,129 Figura 13.…”

Section: Contextualizaçãounclassified

Caracterização de moléculas com potencial bioativo por espectroscopia de ação e mobilidade iônica acopladas à espectrometria de massas

Rodrigues‐Oliveira¹

View full text Add to dashboard Cite

Aos meus pais, por me ensinarem o valor do estudo. AGRADECIMENTOSAgradeço primeiramente a Deus, por acreditar que é pela graça dEle que recebi as oportunidades e capacidade para chegar até este estágio.Agradeço a minha parceira, amiga, companheira e esposa, Caroline, a quem devo minha motivação diária, minha força e meu amor. Obrigado por ter embarcado comigo nesse desafio.Obrigado pela paciência nos fins de semana e no tempo livre que ocupei escrevendo esta tese.Obrigado por me incentivar a ir em frente e por não me deixar me auto sabotar. Obrigado por me fazer ser uma pessoa melhor. Agradeço aos meus pais, Paulo e Célia, por todo o sacrifício que fizeram para dar a mim e ao meu irmão o melhor que puderam. E posso garantir que nada seria melhor que isso. Não consigo expressar em palavras o amor e gratidão que sinto por vocês. Vocês são meu exemplo, minha base, minha raiz. E os grandes culpados se consegui conquistar alguma coisa e se ainda conquistarei. Essa conquista é de vocês também Ao meu irmão, Junior, pelo apoio que sempre me deu, assim como à sua esposa Pamela e aos meus sobrinhos queridos, Isabelle, Júlia e Rafael, pelos momentos de alegria que me proporcionam. A todos os meus familiares, aos quais eu tenho muito amor e carinho. Nós não escolhemos a família em que nascemos, mas se eu tivesse a escolha, com certeza não escolheria outra. Aos meus advogados, Eduardo e Caroline, que sempre valorizaram o meu trabalho e reconheceram que o doutorado é uma tarefa difícil e nunca me deixaram pensar o contrário. Estendo este agradecimento a Mariana, que mesmo longe, continua ocupando seu espaço em nosso coração. Obrigado pelo companheirismo e amizade. Ao meu orientador, Thiago Correra, por todo o ensino, apoio e parceria nestes quatro anos de doutorado. Agradeço também a todos os colegas com quem trabalhei no laboratório MCPL. Foi uma honra ter feito parte deste grupo um prazer compartilhar uma dose de café com vocês no dia-a-dia. Ao Dr. Philippe Dugourd por ter me recebido em seu grupo de pesquisa e ao Dr. Luke MacAleese por ter me supervisionado. Obrigado pela confiança e autonomia. Agradeço também a toda equipe do Grupo SpectroBio pelo acolhimento e auxílio. Ao Prof. Dr. Lucas Ducatti e a Patrick Batista pela colaboração nas análises de QTAIM e NCI. Ao Prof. Dr. Ataualpa Braga por responder pacientemente minhas dúvidas sobre cálculos teóricos.

show abstract

1H NMR and theoretical studies on the conformational equilibrium of tryptophan methyl ester

Cited by 8 publications

References 47 publications

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

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

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and ³J_HH coupling constant analyses

Caracterização de moléculas com potencial bioativo por espectroscopia de ação e mobilidade iônica acopladas à espectrometria de massas

Contact Info

Product

Resources

About

1H NMR and theoretical studies on the conformational equilibrium of tryptophan methyl ester

Cited by 8 publications

References 47 publications

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

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

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and 3JHH coupling constant analyses

Caracterização de moléculas com potencial bioativo por espectroscopia de ação e mobilidade iônica acopladas à espectrometria de massas

Contact Info

Product

Resources

About

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and ³J_HH coupling constant analyses