The GP2A European Conference is a two-day meeting focused on medicinal chemistry and the use of tools to explore all fields of drug discovery and drug design such as molecular modelling, bioorganic chemistry, MS studies, in vitro in vivo assays, and structure activity relationships. Abstracts of keynote lectures, plenary lectures, junior lectures, flash presentations, and posters presented during the meeting are collated in this report.

Fluorescent melatoninergic ligands have been designed by associating the 4-azamelatonin ligands with different fluorophores. The ligands show good affinities for MT1 and/or MT2 receptors and substitution of the fluorophore at positions 2 or 5 of the azamelatonin core had a direct impact on the MT receptors selectivity while grafting the fluorophores on position N1 produced fluorescent ligands with good affinities for both MT1/MT2 receptors. The optimal position N-1, C-2 or C-5 on the 4-azamelatonin ligand appeared strongly dependent upon the nature of the fluorophore itself.

Fluorescent melatoninergic ligands have been designed by associating the 4-azamelatonin ligands with different fluorophores.

The variations of the pharmacological properties of melatonin receptors between different mammalian species in transfected cell lines have been poorly investigated. In the present study, melatonin analogues have been used to characterize the pharmacology of the recombinant ovine melatonin receptor (oMT1) expressed in CHO cell lines and the native oMT1 from the pars tuberalis (PT). Studies with selective ligands on native and transfected oMT1 showed similar properties for binding affinities [r2(PT/CHO) = 0.85]. The affinities and the functional activities of these ligands were compared with the human receptors (hMT1 or hMT2) expressed in CHO cells as well. The oMT1 and hMT1 receptors had similar pharmacological profiles (r2=0.82). Nevertheless, some of the selective compounds at the human receptor presented a reduced affinity at the ovine receptor. Furthermore, some compounds showed marked different functional activities at oMT1 vs. hMT1 receptors. Our findings demonstrated differences in the pharmacological properties of melatonin receptors in ovine and human species.

Compound of formula (I): (CF DRAWING IN BOPI) in which:. n is an integer such that 1 <= n <= 6 ,. A and B together form a naphthalene group, dihydronaphthalene or tetrahydronaphthalene, - R represents hydrogen, a hydroxy group, R 'or OR', R 'being as defined in the description, - G1 represents a halogen, R1 or radical a group -CO-R 1 or -O-CO-R1, R1 being as defined in the description ,. G2 represents a group selected from: (CF DRAWING IN BOPI) X, R2 and R21 are as defined in the description.Medicaments.