X-ray crystal structure, partitioning behavior, and molecular modeling study of piracetam-type nootropics: insights into the pharmacophore

J Med Chem. 1995 Jan 6;38(1):170-9. doi: 10.1021/jm00001a022.

Abstract

To detect possible molecular determinants of amnesia-reverting activity, the conformational properties of a number of rigid and flexible piracetam-type cognition enhancers have been assessed by X-ray diffraction, NMR spectroscopy, and ab initio and high-temperature-quenched molecular dynamics (QMD) calculations. The structures of the preferred conformers in solution derived from 1H-NMR spectral analysis were in good agreement with those found by QMD calculations. Interestingly, the calculation of the average molecular lipophilicity potential on the water-accessible surface of the selected conformers was helpful in interpreting the partitioning behavior observed by measuring octanol-water partition coefficients and capacity factors in reversed-phase high-performance liquid chromatography. While lipophilicity does not play a relevant role, the distance between polar groups, accounted for by the distance between carbonyl oxygens, emerges as a factor, among others, which should influence the amnesia-reversal activity of piracetam-type nootropics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemical Phenomena
  • Chemistry, Physical
  • Crystallography, X-Ray
  • Lipids / chemistry
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Conformation
  • Molecular Structure
  • Nootropic Agents / chemistry*
  • Piracetam / chemistry*
  • Solubility
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Lipids
  • Nootropic Agents
  • Piracetam