Neurotensin has a wide range of pharmacological effects in peripheral
tissues and in the central nervous system, The crystal structures of t
wo potent and selective neurotensin receptor antagonists, SR 48692 (I)
and SR 48527 (II) have been determined and are reported in this work,
By using computational calculations (semiempirical molecular orbital
AMI) we studied the conformational properties of those compounds, incl
uding an inactive analogue SR 49711 (III) for comparison, Considering
the pharmacological properties related to SR 48692 (I) and to opticall
y synthetic analogues SR 48527 (II) and SR 49711 (III), we propose a m
odel of bioactive conformation adopted by those neurotensin receptor a
ntagonists.