COMPARISON OF ELECTROTOPOLOGICAL STATE INDEXES WITH MOLECULAR-ORBITAL PARAMETERS - INHIBITION OF MAO BY HYDRAZIDES

QSAR models for inhibition of monoamine oxidase (MAO) by aryloxyacetohydrazide derivatives were developed for a series of MO parameters computed with the AM1 Hamiltonian. These models were compared to those based on the recently developed electrotopological state index for- skeletal atoms. The structure interpretation is the same for both types of models: the NH group adjacent to the carbonyl group together with the carbon atom, gamma to the NH group, in the hydrocarbon substituent, account for more than 90% of the computed activity. However, the model based on E-state indexes (r2 = 0.9012) is significantly superior to the one based on MO parameters (r2 = 0.7985); the standard deviation for the MO based model (s = 0.27) is 50% larger than that from the E-state based model (r = 0.19). Several points of comparison between the models are presented. This study supports the idea that the electrotopological state is a useful representation of molecular structure information.