Affiliation: Department of Pharmaceutical Chemistry, Medical University of Gdansk, Gdansk 80-416, Poland.
A set of 36 compounds with local anesthetics properties and with the literature values of their biological activity was used to search for relationships between structural parameters obtained from semiempirical RM1 method. Ab initio calculations have been done for molecules in vacuo and also for their hydrated form by placing the molecule under consideration in an environment of water molecules. Finally the data examined the biological activity of compounds was related to their structural indicators using multiparametric regression analysis (multiple regression analysis) with a stepwise progressive method and additional artificial neural network analysis. No effect of hydration on the quantitative structure- activity relationships was observed, furthermore, the used set of independent variables (quantum-chemical parameters) derived from semiempirical calculation method described the properties of particles less than that obtained from the ab initio calculations.