Abstract: A peptide of the formula I X-A-D-Trp-Y wherein X is hydrogen, glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophan, &ggr;-aminobutyric acid or &zgr;-aminocaproic acid; A is D-gluptamic acid or D-iso-glutamic acid; and Y is glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophn, &ggr;-aminobutyric acid, &zgr;-aminocaproic acid, hydroxyl, or an amide group.

Abstract: A peptide of the formula IX--A--D--Trp--Ywherein X is hydrogen, glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophan, .gamma.-aminobutyric acid or .xi.-aminocaproic acid; A is D-gluptamic acid or D-iso-glutamic acid; and Y is glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophn, .gamma.-aminobutyric acid, .xi.-aminocaproic acid, hydroxyl, or an amide group.

Abstract: The invention relates to medicine, specifically, to methods of obtaining biologically active substances with immuno-regulating properties, and can be used in medicine and veterinary science and in experimental biochemistry. The fundamental problem addressed by the invention is that of producing a noval synthetic biologically active peptide with immuno-regulating properties and of the formula: X-Glu-Trp-Y, in which X is H or Gly, Ala, Leu, Ile, Val, NVal, Pro, Tyr, Phe, Trp, D-Ala, D-Leu, D-Ile, D-Val, D-NVal, D-Pro, D-Tyr, D-Phe, D-Trp, .gamma.-aminobutyric acid, .zeta.-aminocapronic acid; Y is Gla, Ala, Leu, Ile, Val, NVal, Pro, Tyr, Phe, Trp, D-Ala, D-Leu, D-Ile, D-Val, D-NVal, D-Pro, D-Tyr, D-Phe, D-Trp, .gamma.-aminobutyric acid .zeta.-aminocapronic acid, --OH, NH.sub.2,N.sub.2 H.sub.3, mono- or di-substituted amide (C.sub.1 -C.sub.3).

Abstract: A peptide of the formula IX-A-D-Trp-Ywherein X is hydrogen, glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophan, .alpha.-aminobutyric acid or .xi.-aminocaproic acid; A is D-glutamic acid or iD-glutamic acid; and Y is glycine, alanine, leucine, isoleucine, valine, N-valine, proline, tyrosine, phenylalanine, tryptophan, D-alanine, D-leucine, D-isoleucine, D-valine, D-N-valine, D-proline, D-tyrosine, D-phenylalanine, D-tryptophn, .alpha.-aminobutyric acid, .xi.-aminocaproic acid, hydroxyl, or C.sub.1 -C.sub.3 substituted amide.