- Palladium-catalyzed benzylation of active methine compounds without additional base: Remarkable effect of 1,5-cyclooctadiene
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(Chemical Equation Presented) The palladium complex prepared from DPPF and Cp(η3-C3H5)Pd is an effective catalyst for the alkylation of active methine compounds with benzylic carbonates under neutral conditions. The additi
- Kuwano, Ryoichi,Kondo, Yutaka
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p. 3545 - 3547
(2007/10/03)
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- TRICYCLIC AMIDES
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The invention relates to a compound selected from these of formula (I) : STR1 in which R 7, R 8, Y, n and A are as defined in the description, and medicinal product containing the same useful for treating a disorder of the melatoninergic system.
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- Synthesis of 2-amido-2,3-dihydro-1H-phenalene derivatives as new conformationally restricted ligands for melatonin receptors
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Tetrahydroanthracene, tetrahydrophenanthrene, and tetrahydrophenalene moieties were used to design novel constrained melatoninergic agents. Compounds 1 and 2 were synthesized from the cyclization of the aryl succinic acids 6a,b followed by catalytic reduction, Curtius degradation to the amino derivatives, and acetylation. The phenalene derivatives 3 were prepared by cyclization of the aza lactones of the corresponding α-N-acetyl amino acids. The ketone derivatives were reduced directly by catalytic hydrogenation to produce the compounds 3. The different compounds were evaluated in vitro in binding assays using 2-[125I]iodomelatonin and chicken brain membranes. Melatonin and 2-acetamido-8-methoxytetralin were used as the reference compounds. The results showed the superiority of the dihydrophenalene framework 3 over those of tetrahydroanthracene and tetrahydrophenanthrene. 3a had relatively good affinity for melatonin receptors (K(i) = 28.7 nM). Introduction of an additional methoxy group gave a derivative (3c) with nanomolar affinity (K(i) = 0.7 nM), confirming the existence of a secondary binding site in the receptor which has been described previously. An increase in the affinity was also observed with the propionamido derivative 3e (K(i) = 6.0 nM). The potential agonist properties of the compound 3e were evaluated on the dermal melanocytes of Xenopus laevis tadpoles. At the concentration of 2.3 nM (5 x K(i)), melatonin gave a melanophore index value of 1. Similarly to melatonin, 3e was shown to be a potent agonist of the melanosome aggregation.
- Mathé-Allainmat, Monique,Gaudy, Florence,Sicsic, Sames,Dangy-Caye, Anne-Laure,Shen, Shuren,Brémont, Béatrice,Benatalah, Zohra,Langlois, Michel,Renard, Pierre,Delagrange, Philippe
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p. 3089 - 3095
(2007/10/03)
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- Synthesis and biological activities of cholecystokinin analogues substituted in position 30 by 3-(1-naphthyl)-L-alanine [Nal(1)] or 3-(2-naphthyl)-L-alanine [Nal(2)]
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Acetyl derivatives of ethyl esters of 3-(1-naphthyl)-D,L-alanine and 3-(2-naphthyl)-D,L-alanine were synthesized through a malonic condensation. Resolution of these derivatives by subtilisin Carlsberg followed by acid hydrolysis afforded the 2 optical isomers of 3-(1-naphthyl)-alanine [Nal(1)] and 3-(2-naphthyl)-alanine [Nal(2)]. The L enantiomers of these amino acids were incorporated into the sequence of cholecystokinin in place of the tryptophan in position 30. The cholecystokinin analogues thus obtained behaved as full agonists, with reduced potencies on rat pancreatic acini and on guinea pig brain membranes, by about one order of magnitude for the Nal(1) derivative, as compared to the potent parent compound Boc-Tyr(SO3H)-Nle-Gly-Trp-Nle-Asp-Phe-NH2.
- Rodriguez,Bernad,Galas,Lignon,Laur,Aumelas,Martinez
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p. 245 - 253
(2007/10/02)
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