Comprehensive Conformational Analysis of N-acetyl-L-triptophane-Nmethylamide. An ab initio and DFT study

J.A.BOMBASARO. A.M.RODRIGUEZ AND R.D.ENRIZ

JOURNAL OF MOLECULAR STRUCTURE THEOCHEM

Elsevier

Lugar: Amsterdam; Año: 2005 vol. 731 p. 177 - 185

0166-1280

A comprehensive conformational analysis has been carried out on N-acetyl-L-tryptophane-N-methylamide. The complete set of minima has been located on the Potential Energy Hypersurface (PEHS) using ab initio (RHF/6-31G(d)) and DFT (B3LYP/6-31G(d)) calculations. Previous ab initio structure determinations at the RHF/3-21G level of theory resulted in 36 different structures. In the present work, a total of 35 and 34 different conformations were obtained at RHF/6-31G(d) and DFT (B3LYP/6-31G(d)) levels, respectively. Diamide conformers, similar to structural building units of the right-handed helix (aL) as well as of polyproline II type structures (3L) were found. However, Ceq 7 (gL) and extended C5 (bL) conformations were the preferred forms for this compound. Sidechain structural (i.e. c1 and c2 conformer interconversions) are also discussed in this paper.N-acetyl-L-tryptophane-N-methylamide. The complete set of minima has been located on the Potential Energy Hypersurface (PEHS) using ab initio (RHF/6-31G(d)) and DFT (B3LYP/6-31G(d)) calculations. Previous ab initio structure determinations at the RHF/3-21G level of theory resulted in 36 different structures. In the present work, a total of 35 and 34 different conformations were obtained at RHF/6-31G(d) and DFT (B3LYP/6-31G(d)) levels, respectively. Diamide conformers, similar to structural building units of the right-handed helix (aL) as well as of polyproline II type structures (3L) were found. However, Ceq 7 (gL) and extended C5 (bL) conformations were the preferred forms for this compound. Sidechain structural (i.e. c1 and c2 conformer interconversions) are also discussed in this paper.aL) as well as of polyproline II type structures (3L) were found. However, Ceq 7 (gL) and extended C5 (bL) conformations were the preferred forms for this compound. Sidechain structural (i.e. c1 and c2 conformer interconversions) are also discussed in this paper.eq 7 (gL) and extended C5 (bL) conformations were the preferred forms for this compound. Sidechain structural (i.e. c1 and c2 conformer interconversions) are also discussed in this paper.(gL) and extended C5 (bL) conformations were the preferred forms for this compound. Sidechain structural (i.e. c1 and c2 conformer interconversions) are also discussed in this paper.c1 and c2 conformer interconversions) are also discussed in this paper.