title: Synthesis and biological activity of N-methylated analogs of endomorphin-2.
abstract: In this paper, we describe the synthesis of a series of endomorphin-2 analogs containing N-methylated amino acids, consecutively in each position. The mu-opioid receptor binding affinities of the new analogs were determined in the displacement experiments. Their in vivo antinociceptive activity was assessed in the hot-plate test in mice after central (icv) and peripheral (ip) administration. [Sar2]endomorphin-2, which had the highest mu-receptor affinity, also showed the strongest analgesic effect when administered centrally and was the only analog that retained activity after peripheral injection.
authors.affiliation: Institute of General and Ecological Chemistry, Technical University of Lodz, Lodz, Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Kruszynski
authors.forename: Jakub
authors.initials: J
authors.lastname: Fichna
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: do-Rego
authors.forename: Tomasz
authors.initials: T
authors.lastname: Janecki
authors.forename: Piotr
authors.initials: P
authors.lastname: Kosson
authors.forename: Wanda
authors.initials: W
authors.lastname: Pakulska
authors.forename: Jean
authors.initials: J
authors.lastname: Costentin
authors.forename: Anna
authors.initials: A
authors.lastname: Janecka
mesh_terms: D000818:Animals; D008297:Male; D008745:Methylation; D051379:Mice; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; C105294:endomorphin 2