The Folded Conformation of Perezone Revisited. Long Range nOe Interaction in Small Molecules: Interpretable Small Signals or Useless Large Artifacts?

Authors

  • Elizabeth Reyes-López Universidad Nacional Autónoma de México
  • Beatriz Quiroz-García Universidad Nacional Autónoma de México
  • Pablo Carpio-Martínez Universidad Nacional Autónoma de México
  • Jesús Jiménez-Barbero 1. Infectious Disease Program 2. IKERBASQUE, Basque Foundation for Science
  • Nuria Esturau-Escofet Universidad Nacional Autónoma de México
  • Gabriel Cuevas Universidad Nacional Autónoma de México

DOI:

https://doi.org/10.29356/jmcs.v61i3.343

Keywords:

NOE, conformational analysis, π/π interactions, hydrodynamic radii, NMR spectroscopy

Abstract

The nuclear Overhauser effect (nOe) is a consequence of the cross-relaxation and it involves the transfer of nuclear spin polarization from one population to another intra or inter-molecularly. It is generally accepted that a proton-proton distance between 4 and 5 Å is the upper limit for the occurrence of measurable nOe´s in small molecules. However, we herein show how detectable nOe´s may, in fact, take place between alkyl groups of quinones with substitutions at 1-4 relative positions, showing distances longer than 6 Å. Although the signals of interest are very small, of the order of 1% of a normal nOe, so a priori are considered artifacts originated by decoupling modulation, they maintain, properties that make them interesting and give them coherence as interpretable signals. If the signals of interest are not artifacts these observations represent an important breakthrough with impact on the standard protocols that are commonly used for determination of molecular structure and conformation.

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Author Biographies

Elizabeth Reyes-López, Universidad Nacional Autónoma de México

Departamento de Fisicoquímica, Instituto de Química

Beatriz Quiroz-García, Universidad Nacional Autónoma de México

Departamento de Fisicoquímica, Instituto de Química

Pablo Carpio-Martínez, Universidad Nacional Autónoma de México

Departamento de Fisicoquímica, Instituto de Química

Jesús Jiménez-Barbero, 1. Infectious Disease Program 2. IKERBASQUE, Basque Foundation for Science

  1. CIC bioGUNE

Nuria Esturau-Escofet, Universidad Nacional Autónoma de México

Departamento de Fisicoquímica, Instituto de Química

Gabriel Cuevas, Universidad Nacional Autónoma de México

Departamento de Fisicoquímica, Instituto de Química

Published

2017-10-26

Issue

Section

Regular Articles