THEORETICAL INVESTIGATIONS ON ANTIMUSCARINIC ETHYLTHIO AND ETHOXY DERIVATIVES OF ADIPHENINE AND 4-DAMP

The unexpected differences in biological activity of some sulfurated m uscarinic antagonists, compared to their oxygenated analogues, is expl ained using theoretical methods based on molecular mechanics and molec ular orbital calculations. Interaction energies calculated for both ty pes of ligands with a receptor model (M(1)) show that binding is more favourable for the sulfurated than the oxygenated molecules. This can be explained with the different geometrical and electronical propertie s (but not conformational) of the molecules.