Multipoint recognition of catecholamines by hydrindacene-based receptors accompanied by the complexation-induced conformational switching

Chemistry. 2005 Jan 21;11(3):815-24. doi: 10.1002/chem.200400819.

Abstract

The molecular recognition of catecholamines by hydrindacene-based receptors 1 and 2, as well as the durene-based receptor 3, and the guest-induced conformational changes are reported. These receptors selectively bind adrenaline and dopamine salts through the guests' ammonium group and 3-hydroxyl group on the aromatic ring. In the case of adrenaline, an additional hydrogen bond with a benzylic hydroxyl group is formed. In 2 % CD3CN/CDCl3, the association constants are of the order of 10(4) M(-1), which is much larger than with guests without the 3-hydroxyl groups (10(3) M(-1)). The two amide groups of receptor 1 can rotate freely around the C(aromatic)--C(amide) bond, whereas the tert-amide in 2 changes between two stable conformations at a slow enough rate to allow detection by (1)H NMR spectroscopy. In the absence of a guest molecule, the syn-conformer is less stable than the anti-conformer. On complex formation with adrenaline, the syn-conformer becomes dominant due to an intramolecular dipole-reversal effect in addition to multipoint hydrogen bonding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Catecholamines / chemistry*
  • Crystallography, X-Ray
  • Epinephrine / chemistry
  • Indenes / chemical synthesis*
  • Indenes / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Stereoisomerism

Substances

  • Catecholamines
  • Indenes
  • hydrindacene
  • Epinephrine