| Abstract
| - The solid phase procedure, based on the Fmoc chemistry, was usedto prepare some opioiddeltorphin(H-Tyr-d-Ala-Phe-Asp-Val-Val-Gly-NH2, DEL C)and dermorphin (H-Tyr-d-Ala-Phe-Gly-Tyr-Pro-Ser-NH2, DER) analogues in which ad-glucopyranosyl moiety isβ-O-glycosidicallylinked to a Thr4 or Thr7 side chain. Theiractivities were determined in binding studies basedon displacement of μ- and δ-receptor selective radiolabels from ratbrain membrane synaptosomes, in guinea pig ileum and rabbit jejenum bioassays, and, invivo, by a mouse tail-flicktest after intracerebroventricular (icv) and subcutaneous (sc)administrations. The glycoanalogues modified at position 4 displayed low opioid properties, whileThr7-glycosylatedpeptides retained high δ- or μ-selectivity and remarkable activityin vivo. In particular, assystemic antinociceptive agents, the latter glucoside-bearing compoundswere more potent thanthe parent unglycosylated peptide counterparts, showing a high blood tobrain rate of influxwhich may be due to the glucose transporter GLUT-1.
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