N6-N7 - A MODIFICATION OF THE N6-C8 MODEL FOR THE BINDING-SITE ON ADENOSINE-A1-RECEPTORS WITH IMPROVED STERIC AND ELECTROSTATIC FIT

A modification of ''N6-C8'' model, named ''N6-N7'', is proposed for th e binding site on adenosine Al receptor. The steric and electrostatic fit of the two models is tested on the basis of eight reference compou nds. The steric fit is assessed by the parameter mean value of the roo f mean squares RMS(mean) of the distances between two fitted atoms in fifty six fitting pairs. The electrostatic fit is assessed by the para meter mean distances between atoms producing areas with negative elect rostatic potential and between atoms that act as donors in H-bond form ation. The ''N6-N7'' model demonstrates better steric and electrostati c fit in comparison with the ''N6-C8'' model.