Electronic Structure and Serotonin Receptor Binding Affinity of 7-Substituted Tryptamines QSAR of 7-Substituted Tryptamines

A QSAR study was carried out seeking a relationship between the receptor binding affinities and the molecularelectronic structures of a group of 7-substituted tryptamines. The results suggest that these molecules interact with the rat stomach fundus serotonergic receptor by charge transfer from the aromatic nucleus and that there are pockets in the receptor which place limits on the sizes of acceptable N- and ot-carbon substituents. AIso, the charge density available at carbon atom 7 and the size of the C-7 substituent as estimated by a calculated steric factor seem to make important contributions to an optimal interaction between the IAA and the receptor molecules.This work has received financial support from the University of Chile (DIB Project Q-2442), and from the Fondo Nacional de Ciencia (Project 1075)