Abstract: The present invention relates to a process for the preparation of high purity crystalline peptides Arg Lys Asp hydrate acetate and Arg Lys Asp Val from crude, amorphous peptides Arg Lys Asp and Arg Lys Asp Val hydrate acetate.The process is characterized in thatthe crude, amorphous peptide Arg Lys Asp or Arg Lys Asp Val is let stand at room temperature in 5 to 20 unit volume of ethanol containing 0.5 to 4.0% by volume of acetic acid and 5 to 25% by volume of water, wherein the volume unit is calculated for the mass unit of the material and mass unit relates to volume unit as g relates to ml,then the crystallized peptide is separated from the crystalline suspension, preferably after cooling.

Abstract: The new peptides of the Formulae(1) Glp-Lys-NH.sub.2(2) Glp-Glu-Lys-NH.sub.2(3) Arg-Lys-Glu-NH.sub.2(4) Arg-lys-Asp-NH.sub.2(5) Arg-Lys-Glu-OH(6) Arg-Lys-Gln-OH(7) Leu-Val-Ala-OH(8) Arg-Orn-Asp-Val-NH.sub.2(9) Arg-Orn-Asp-Val-OH(10) Lys-Glu-Lys-Lys-OH(11) Lys-Leu-Lys-Lys-OH(12) Lys-Asp-Leu-Lys-OH(13) Glu-Leu-Val-Ala-OH and(14) Leu-Pro-Ala-Gly-OHand acid addition salts thereof inhibit the proliferation of leukaemic cells and exhibit immunostimulant effect.

Abstract: The invention relates to novel peptides and their acid addition salts, suppressing the function of the immune system, pharmaceutical compositions containing these peptides as well as to a process for preparing these peptides and compositions. The peptides are represented by formulae (1) to (16): ##STR1## The novel peptides are useful for the therapy of diseases where a decrease in the activity of the immune system is desirable.

Abstract: The invention relates to octapeptides of the formulaX-Arg-Val-Tyr-Y-His-Pro-W (I)whereinX is a sarcosyl, lactoyl or hydroxyacetyl radical,Y is cyclopentylglycyl or cyclohexylglycyl, andW is an alanine radical or lactic acid radicalhaving angiotensine-II antagonistic activity.

Abstract: Peptides affecting the immune regulation selected from the following group:Arg-Lys-AspArg-Lys-Asp-ValArg-Lys-Asn-ValArg-Lys-Asu-ValArg-Lys-Ala-ValArg-Lys-Asp-AlaArg-Lys-Asp-IleArg-Lys-Glu-ValArg-Ala-Asp-ValArg-Asp-Lys-ValAla-Lys-Asp-ValLys-Arg-Asp-ValGlp-Arg-Lys-AspGlp-Arg-Lys-Asp-ValGlp-Arg-Lys-Asp-Val-Tyr and salts, amides lower alkyl esters and protected derivatives thereof.

Abstract: New octapeptides of the general formula (I),X--Arg--Val--Tyr--Ile--His--Pro--Y--OA (I)whereinX stands for the acyl group of an N-methylamino acid or the acyl group of an aliphatic .alpha.-hydroxy- or .alpha.-aminooxycarboxylic acid,Y is the residue of an aliphatic amino acid, andA is a C.sub.1-5 alkyl group, are prepared so that the protecting groups of a protected octapeptide derivative of the general formula (II),B--X--Arg(C)--Val--Tyr(D)--Ile--His(E)--Pro--Y--OA (II)whereinB is a group removable by acidolysis or catalytic hydrogenation,C is a group for the temporary protection of the guanidino group on the Arg moiety,D is a group for the temporary protection of the aromatic hydroxy group on the Tyr moiety,E is a group for the temporary protection of the imidazole group on the His moiety, andA, X and Y are as defined above,are removed either stepwise or in a single step. If desired, a compound of the general formula (I) is converted into its acid addition salt or pharmaceutically acceptable complex.

Abstract: New angiotensin-II analogues of the general formula (I),X-Arg-Val-Tyr-Ile-His-Pro-Y-OA (I)whereinX stands for the acyl group of an N-methylamino acid, or the acyl group of an aliphatic .alpha.-aminooxy- or .alpha.-hydroxycarboxylic acid,Y is the residue of an aliphatic .alpha.-hydroxycarboxylic acid, andA is hydrogen or a C.sub.

Abstract: Angiotensin II analog of the formula IX-Arg-Val-Tyr-Ile-His-Pro-Y (I)whereinX is a radical derived from an aliphatic .alpha.-aminooxy-carboxylic acid andY is a radical derived from an aliphatic .alpha.-amino-carboxylic acid,and acid addition salts and complexes thereof with antagonistic properties useful in the diagnosis and treatment of hypertensions depending on renin.