New histamine H-3-receptor antagonists were prepared and investigated for their ability to increase synthesis and release of histamine mediated by inhibition of presynaptically located H-3-receptors. Acyl derivatives of histamine methylated at different positions show poor activity at H-3-receptors, whereas N-alpha-alkyl and particularly N-alpha-acyl derivatives of histamine possess moderate to good H-3-receptor antagonist activity. A not-too-bulky and lipophilic residue in an optimal distance of 3-4 methylene groups from the amide function leads to potent and selective H-3-receptor antagonists. N-alpha-Histamine-gamma-phenylbutyramide 11 and N-alpha-histamine-gamma-cyclohexylbutyramide 13 are H-3-receptor antagonists with -log K-i of 7.1 and 7.3, respectively. Structure-activity relationships of different substitution patterns are discussed.
NOUVEAUX DERIVES DE L'IMIDAZOLE, LEUR PREPARATION ET LEURS APPLICATIONS THERAPEUTIQUES
申请人:INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE (INSERM)