title: Opiate-like peptides. Part VIII. Methylamides and dimethylamides of [D-Leu5]-enkephalin and [D-Ala2, D-Leu5]-enkephalin. Synthesis and analgesic activity.
abstract: Syntheses of [D-Ala2, D-Leu5]-enkephalin, methyl ester of [D-Ala2, D-Leu3]-enkephalin, methylamides and dimethylamides of [D-Leu5]-enkephalin and [D-Ala2, D-Leu5]-enkephalin are described together with their analgesic activity determined on the basis of four analgesic tests: the hot-plate method, the reaction to electric stimulus, the tail immersion test and the frequency of writhing syndrome test. The neurotoxicity was estimated by the rota-rod test. The most pronounced analgesic effect was induced by compound: [D-Ala2, D-Leu5]-enkephalin, [D-Ala2, D-Leu5-OMe]-enkephalin and [D-Ala2, D-Leu5-NMe2]-enkephalin. In the tail immersion test all analogs did not exhibit analgesic activity.
mesh_terms: D000700:Analgesics / Q000138:chemical synthesis*; D000818:Animals; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D004744:Enkephalin, Methionine / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D009422:Nervous System Diseases / Q000139:chemically induced; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000700:Analgesics; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine