139143-40-1Relevant articles and documents
Synthesis and antinociceptive activity of [D-Ala2]Leu-enkephalin derivatives conjugated with the adamantane moiety
Kitagawa, Kouki,Mizobuchi, Noriko,Hama, Teruo,Hibi, Tohru,Konishi, Ryoji,Futaki, Shiroh
, p. 1782 - 1787 (2007/10/03)
Based on the physicochemical and pharmacological properties of drugs having an adamantane skeleton, an adamantane-based moiety was evaluated as a drug carrier for poorly absorbed compounds, including peptides, active towards the central nervous system (CNS). Seven [D-Ala2]Leu-enkephalin derivatives conjugated with an adamantane-based moiety at the C-terminus or N-terminus were prepared by the solution-phase method and their biological activities were examined. The compounds derivatized at the C-terminus through an ester or amide linkage were much more lipophilic than the parent peptide and exhibited moderate in vitro opioid activity (guinea-pig ileum assay). Among them, four derivatives (1, 2, 4, 5), exhibited significant antinociceptive effects in an in vivo assay (mouse tail-pressure test) after subcutaneous administration. This result suggests that the introduction of the lipophilic adamantane moiety into [D-Ala2]Leu- enkephalin would improve the permeation of the poorly absorbed parent peptide through the blood-brain-barrier (BBB) without loss of antinociceptive effect.