Design and synthesis of 3-phenyltetrahydronaphthalenic derivatives as new selective MT2 melatoninergic ligands. Part II

Following our studies of the melatoninergic receptors, we have developed new tetrahydronaphthalenic derivatives of melatonin that have been tested as selective melatonin receptors ligands. Regarding the role of the phenyl substituent to obtain selective ligands, modulation of selectivity and activity have been achieved by modi. cations of the acyl group and substitutions on the phenyl ring. Ten of the seventeen evaluated derivatives have MT2 receptor affinity similar to that of melatonin. Moreover, we have achieved remarkable MT2 selectivity over MT1 (selectivity > 100) and have been able to further extend the RSA of the tetrahydrophthalenic series. However, the compounds presented here display partial agonist or antagonist behavior instead of full agonist. (C) 2009 Elsevier Ltd. All rights reserved.