Inclusion of menadione with cyclodextrins studied by calorimetry and spectroscopic methods

Abstract

AbstractComplex formation of menadione with α‐, hydroxypropyl α‐, β‐, hydroxypropyl‐β‐, methyl‐β‐ and hydroxypropyl‐γ cyclodextrins in aqueous solution at 298.15 K was studied by using isothermal titration calorimetry, 1H NMR, and UV–vis spectrophotometry. The experimental data indicated the partial insertion of menadione into macrocyclic cavity upon formation of two alternative types of 1:1 inclusion complexes, whose thermodynamic parameters (K, ΔcG0, ΔcH0, and ΔcS0) were calculated. The influence of host size on the complex formation process was analyzed. β‐Cyclodextrin and its hydroxypropylated and methylated derivatives were found more effective binders towards menadione than α‐ and γ‐cyclodextrins. Copyright © 2007 John Wiley & Sons, Ltd.