title: [Synthesis and study of cyclic and linear analogs of neurotensin].
abstract: New cyclic analogues of neurotensin (NT): [cyclo (13----8), Gly8]NT-(8-13), [cyclo (13----7), Gly7]NT-(7-13), [cyclo (13----5 epsilon), Lys5]NT-(5-13), [cyclo (13----4 epsilon), Lys4]NT-(4-13), and their linear precursors have been synthesized. The latter (protected linear compounds) were prepared by solid-phase peptide synthesis, and cyclization was attained by using diphenylphosphoryl azide. Cyclization of C-terminal hexa- and octapeptide fragments of NT was found to lead to cycloanalogues possessing high depressor activity. As judged by CD spectral data in aqueous solution, the cyclohexapeptide analogue has a relatively rigid conformation different from its linear counter-part and the NT-(9-13) fragment, whereas NT, its cyclohepta- and cyclononapeptides have random structure.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009496:Neurotensin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000494:pharmacology; D011487:Protein Conformation; D051381:Rats
chemical_list: D010456:Peptides, Cyclic; D009496:Neurotensin
vernacular_title: Sintez i issledovanie tsiklicheskikh i lineĭnykh analogov neĭrotenzina.