On the impossibility of determination of stepwise binding constants for the 1 : 2 complex of (+)-camphor with alpha-cyclodextrin

Org Biomol Chem. 2003 Feb 7;1(3):581-4. doi: 10.1039/b209272g.

Abstract

Knowledge of stepwise binding constants for complexes with higher than 1:1 stoichiometry would allow one to study the cooperativity of their formation. However, a detailed analysis of partitioning of the overall binding constant beta 12 determined by NMR titrations for the 1:2 complex of (+)-camphor with alpha-cyclodextrin into the stepwise ones K1 and K2 carried out analogously to published procedures revealed that the partitioning cannot be carried out unequivocally for K1 << K2. The programs for partitioning cannot be used as a black box and a satisfactory reproduction of the experimental dependence of relative shifts as a function of relative CD concentration should not be the only criterion of the reliability of the stepwise binding constants obtained using such programs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Camphor / chemistry*
  • Camphor / metabolism
  • Cyclodextrins / chemistry*
  • Cyclodextrins / metabolism
  • Kinetics
  • Magnetic Resonance Spectroscopy / methods
  • Titrimetry
  • alpha-Cyclodextrins*

Substances

  • Cyclodextrins
  • alpha-Cyclodextrins
  • Camphor
  • alpha-cyclodextrin