Índices cuadráticos 3D-quirales basados en átomos. Parte 3: Predictión de la afinidad de unión de estereoisómeros del fenoterol al receptor adrenérgico β ₂

The non-stochastic and stochastic atom-based three dimensional (3D)-chiral quadratic indices are applied to predict the binding affinities of 26 stereoisomers of fenoterol with the β ₂-adrenoceptor (β ₂-AR). The prediction of β ₂-AR binding affinities of the stereoisomers is carried out by multiple linear regression analysis. Two statistically significant QSAR models are obtained when non-stochastic (R ² = 0.941 and s = 0.19) and stochastic (R ²= 0.947 and s = 0.18) 3D-chiral quadratic indices are used. These models show adequate predictive power (assessed by the leaveone-out cross-validation experiment), yielding values of q ² = 0.909 (s _Cv= 0.219) and q ² = 0.917 (s _cv = 0.208), respectively. These models compare favorably with a 3D-QSAR equation obtained with the CoMFA method (R ² = 0.920, q ² = 0.847 and s _cv = 0.309). The results of our work demonstrate the usefulness of our topological approach for the prediction of biological activity, even in those studies in which the three-dimensional configuration of the chemicals play an important role in the bioactivity.