Quantitative Structure-Stability Relationships in the Inclusion Complexes of Steroids with Cyclodextrins

The inclusion constants of a series of 18 steroid hormones in alpha, beta, and gamma-cyclodextrin, are analyzed as a function of the structure by the PLS method. To describe the steroid structure various kinds of descriptors are used: physicochemical properties of the compounds, physicochemical parameters of substituents, connectivity indexes and indicator variables The analysis permits the establishment of quantitative relationships between each inclusion constant and the structural features. For 1:1 alpha-cyclodextrin-steroid complexes a model, which can be used to predict the stability for new complexes, is developed and some inference on the disposition of the guest compound in the cyclodextrin cavity is drawn.