Deca-, undeca-, dodeca- and tridecapeptides with thymic activity

摘要

Novel peptides of the formula: wherein: A, A' and A'' are each independently Gly, D-Ala, D-Leu, or D-Trp, wherein A may optionally be N-alkylated or N-acylated; B is Pro, DELTA 3-Pro, Thz, or diMeThz; C and C' are each independently Thr, Ser, Val, or alloThr; D is Glu, Gln, Asp, or Asn; R is hydrogen, or is lower alkyl or lower acyl, substituted for one of the hydrogens on the epsilon -amino group of the lysyl residue; X is Cys, Ala, ABU, or Cys(Me); and Y is selected from the group consisting of hydroxy, Pro, Pro-Leu, and Pro-Leu-Met, -NH2, ProNH2, Pro-LeuNH2 and Pro-leu-MetNH2; and the pharmaceutically acceptable salts thereof, are useful for increasing immunologic competence. Methods for preparation of the peptides are also described.