ABSTRACT
J.E. Dubois, J.P. Doucet*, A. Panaye and B.T. Fan Institut de Topologie et de Dynamique des Systemes, associe au CNRS,
UPRES-A 7086 Universite Paris 7 - Denis Diderot, 1 rue Guy de la Brosse 75005 Paris, France
The originality of the DARC topological approach lies: - first in an ordered description of the structural environment connected to the
focus of a property, each site in the environment being identified, and - secondly in a formal organisation of sets of compounds into topological
filiations. These features allow for associating the evolution of a property and the evolution of the structural description induced by a progressive perturbation of the environment (PELCO method). A property is evaluated by summation of the individualised contributions of each site and terms expressing possible interactions between them. Criteria for the selection of the training set, and the choice of the relevant correlation method (multilinear regression or artificial neural networks) are illustrated on various properties localised on an atom or a fragment (NMR chemical shift, IR frequency, rate constant, pharmacological activity...) or concerning the whole structure (enthalpies of formation...). Alternate strategies consider a unique perturbation of a focus in an evolving environment (PULFO method).
