A QSAR and molecular modeling study on a series of 3, 4-dihydro-1-isoquinolinamines and thienopyridines acting as nitric oxide synthase inhibitors

Abstract

<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">A<b style="mso-bidi-font-weight:normal"> </b>quantitative structure-activity relationship (QSAR) and molecular modeling study were performed on a series of 3,4-dihyro-1-isoquinolinamines and thienopyridines reported by Beaton et al. [Beaton <i>et al</i>. (2001)<i> Bioorg Med Chem</i> <i style="mso-bidi-font-style:normal">Lett</i> <span style="mso-bidi-font-style:italic">11, 1023-1026, 1027-1030] as potent, highly selective inhibitors of two isoforms of nitric oxide synthase (NOS) — neuronal NOS (nNOS) and endothelial NOS (eNOS), in order to find the physicochemical properties that governed their activity and the mode of interaction with the receptors, so that still more potent compounds in the series could be suggested. A multiple regression analysis revealed that <span style="mso-bidi-font-weight:bold">nNOS and eNOS<span style="mso-bidi-font-weight: bold"> inhibition potency of these compounds could be controlled by their hydrophobic property and molar refractivity, respectively. Thus, <span style="mso-bidi-font-weight:bold">nNOS and eNOS<span style="mso-bidi-font-weight: bold"> inhibition was indicated to involve the hydrophobic interaction and steric effects, respectively, suggesting some structural differences of the two isoforms of NOS. Based on the correlations obtained, some new, more potent compounds belonging to the series were predicted. These compounds were then docked into the receptors to see their interactions and find out the docking scores. The docked structures of two representative compounds, whose interaction energies with nNOS and eNOS, respectively were found to be the lowest, were given as an example to exhibit the possible orientation of the compounds to interact with the receptors.</span></span></span></span></span></span>