Synthèse de nouveaux analogues de la lysine‐vasopressine: Asp(NH₂)⁴‐lysine‐vasopressine, Ala⁴‐lysine‐vasopressine, Sér⁴‐lysine‐vasopressine, Sér⁵‐lysine‐vasopressine, Val⁷‐lysine‐vasopressine et (N^ϵ‐For‐Lys)⁸‐vasopressine

Abstract

Abstract Six new analogues of Lysine‐vasopressin have been synthesized 1 Asp(NH 2 ) 4 ‐lysine‐vasopressin, Ala 4 ‐lysine‐vasopressin, Ser 4 ‐lysine‐vasopressin, Ser 5 ‐lysine‐vaso‐pressin, Val 7 ‐lysine‐vasopressin and (N ϵ ‐For‐Lys) 8 ‐vasopressin. All were prepared by the 3 + 6 scheme. The hexapeptides necessary for the synthesis of the former four were prepared by recurrent synthesis, those utilized for the synthesis of the last two, by condensation of two tripeptides. The analogues substituted in position 4 were found to still possess a significant level of activity, whereas those substituted in positions 5 or 7 were almost inactive. Masking of the ϵ‐amino group of lysine in position 8 caused no decrease in the oxytocic activities, but affected, to a different degree, the pressor and the antidiuretic activities.