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Synthesis and biological activity of N-methylated analogs of endomorphin-2
Rafal Kruszynski1, Jakub Fichna, Jean-Claude do-Rego
1Institute of General and Ecological Chemistry, Technical University of Lodz, Lodz, Poland.
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.
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