Synthèse de la désamino¹‐Arg⁸‐vasopressine et de la désamino¹‐Phe²‐Arg⁸‐vasopressine, deux analogues possédant une activité antidiurétique plus élevée et plus sélective que celle des vasopressines naturelles

Deamino 1 ‐Arg 8 ‐vasopressin and deamino 1 ‐Phe‐ 2 Arg 8 ‐vasopressin have been synthesized by condensation of L ‐glutaminyl‐ L ‐asparaginyl‐S‐benzyl‐ L ‐cysteinyl‐ L ‐prolyl‐G‐tosyl‐ L ‐arginyl‐glycinamide with β‐benzylthio‐propionyl‐ L ‐tyrosyl‐ L ‐phenyl‐alanylazide and β‐benzylthio‐propionyl‐ L ‐phenylalanyl‐ L ‐phenylalanylazide, respectively. After removal of the protecting groups and oxidation with hydrogen peroxide, the deamino‐nonapeptides have been purified by counter‐current distribution. Deamino 1 ‐Arg 8 ‐vasopressin as well as deamino 1 ‐Phe 2 ‐Arg 8 ‐vasopressin exhibit a higher antidiuretic activity (1300 IU/mg and 800 IU/mg, respectively) and a lower pressor activity than arginine‐vasopressin. This confers to both analogues, and especially to the latter, a remarkable selectivity of the antidiuretic action.