intercalating, reverse transcriptase (RT) inhibitory and multidrug resistance effluxpump inhibitory properties. The intercalating activity and the RT inhibitory activity of the derivatives suggest that ellipticine analogues bind at an allosteric binding site on RT or that this inhibition could be controlled at the DNA level. The MDR effluxpump inhibitory activities of these derivatives, however, appears to be
Interaction of novel condensed triazine derivatives with central and peripheral type benzodiazepine receptors: synthesis, in vitro pharmacology and modelling
Structurally related sets of triazino-quinoline, triazino-isoquinoline and pyrido-triazine derivatives were synthesised and their binding interactions with central (CBR)- and peripheral-type (PBR) benzodiazepine binding sites have been characterised. Of 33 compounds tested, a new compound, 2-(4-methylphenyl)-3H-[1,2,4] triazino [2, 3-a] quinolin-3-one (1 g) showed the lowest CBR binding inhibition constant (K-i = 42 +/- 9 nM) and the highest CBR over PBR selectivity (> 1300). All but the 4-methylphenyl (1 g) structural modifications decreased the affinity and selectivity of the parent compound, 2-phenyl-3H- [ 1,2,4]triazino[2,3-a]quinolin-3-one (1d) (K-i = 69 +/- 9 nM, selectivity > 890). Molecular interactions between selected ligands (standards and triazine derivatives) and alpha(1)gamma(2) subunit-interface residues in a GABA(A) receptor extracellular domain homology model have been calculated. Comparing data with calculations confirmed hydrogen bonding to gamma(2)Thr142 and hydrophobic interaction with alpha 1His101 as being essential for high-affinity CBR binding. (c) 2006 Elsevier SAS. All fights reserved.