Abstract: A method for treating septic shock by administering a retroinverted tetrapeptides of formula I ##STR1## wherein R is a hydrogen atom or the side-chain of threonine; R.sub.1 is the side-chain of arginine, leucine or glutamine; and R.sub.2 is a hydrogen atom or a metabolically perishable acyl group; with the proviso that when R.sub.1 is the side-chain of arginine, R cannot be the side-chain of threonine; diastereo-isomeric forms and pharmacologically acceptable salts, esters and amides thereof.

Abstract: Retro-inverted tetrapeptides of formula I ##STR1## wherein R is a hydrogen atom or the side-chain of threonine; R.sub.1 is the side-chain of arginine, leucine or glutamine; and R.sub.2 is a hydrogen atom or a metabolically perishable acyl group; with the proviso that when R.sub.1 is the side-chain of arginine, R cannot be the side-chain of threonine; diastereo-isomeric forms and pharmacologically acceptable salts, esters and amides thereof. These compounds are useful as immuno-stimulating agents.

Abstract: An ELISA method with competitive inhibition is described for determining antisporozoite antibodies of P. Falciparum in human blood samples and in mosquito extract, which uses a single plate pretreated with only the synthetic antigen (NANP).sub.20 using, as total competitive inhibitor for the formation of the complex between the synthetic antigen adsorbed on the plate and the antibody contained in the sample, the (NANP).sub.20 synthetic peptide in a weight ratio of at least 20:1 with respect to the adsorbed antigen. Because of its high specificity, sensitivity and speed, the method is particularly suitable for epidemiological studies on malaria.

Abstract: Polypeptide useful for the preparation of antimalarial vaccines and of diagnostic kits for the detection of antisporozoite antibodies in clinical samples of malariated persons, constituted by: a synthetic peptide, which repeates the region I of P. falciparum and by a variable number of repetitive tetrapeptide units of CS protein of P. falciparum linked to each other by an amidic bond between the tail proline of I region and the head asparagine of the first tetrapeptide.

Abstract: Synthetic polypeptides constituted by at least two consecutive repeating units of (Asn-Asn-Pro) sequence are powerful immunogens in test animals.The formed antibodies recognize both the synthetic polypeptides and the immuno-dominant epitope of the circumsporozoitic protein of Plasmodium falciparum.Said polypeptides, which can be obtained in pure form, are particularly useful for the preparation of antimalarial vaccines and of diagnostic kits for the determination of malarial affections.

Abstract: This invention relates to new gem-diamino derivatives of general formula (I) ##STR1## where R is the side chain of an amino acid, of which any functional groups are suitably protected, andX is an acyl group chosen from the group consisting of 2-nitrobenzoyl, 4-chloro-butyryl, acetoacetyl, 4-bromo-butyryl, (2-nitrophenoxy)-acetyl and 2-methyl-2-(2'-nitro-phenoxy)propionyl, of use in introducing gem-diamino residues into retro-inverso peptides. The invention further relates to a method for the synthesis of retro-inverso peptides in which the gem-diamino residue or residues are introduced using the new compound (I).

Abstract: New analogues of thymopentin (TP5) and of its tetrapeptide fragment (TP5.sup.1-4) containing two non-contiguous retro-inverted bonds in the peptide chain are described which are of the general formula (I) ##STR1## where R is hydrogen or an acyl radical, and R.sup.1 is an --OR.sup.2 group or an ##STR2## group where R.sup.2 is a hydrogen atom or a hydrocarbon radical, and R.sup.3 is a hydrogen atom or a hydroxyl group, and the corresponding pharmaceutically acceptable salts of acid or basic addition, possess immunomodulating activity.

Abstract: An immunoenzymatic method for the detection of anti-Plasmodium falciparum-sporozoite antibodies in a sample of human blood, which operates, in homogeneous phase, and under suitable conditions, with a synthetic polypeptidic antigen (P), a synthetic antigen-enzyme (P-E) conjugate, wherein said antigen is capable of specifically reacting with the anti-Plasmodium falciparum-sporozoite antibodies (Ab) possibly present in the sample, and an inert substance capable of quantitatively precipitating the antibody-synthetic antigen-enzyme complex (Ab-P-E).The method, due to its specificity, sensitivity, reproducibility and rapidity, is particularly useful in the epidemiological investigations into malaria and in the evaluation of the efficacy of an antimalarial vaccine.

Abstract: New retro-inverso analogs of thymopentin (TP5) and of its tripeptide fragment (TP5.sup.1-3) of general formula (I) ##STR1## are described wherein R is hydrogen or an acyl radical, and R.sup.1 is --OR.sup.2 or ##STR2## wherein R.sup.2 is hydrogen or a hydrocarbyl radical, and the corresponding pharmaceutically acceptable acid- or base-addition salts. A process of preparing the tripeptide fragment of formula I is also described.The new compounds are enzyme-resistant immunomodulatory peptides.

Abstract: An improvement is described in the synthesis method for N.sup..alpha. -trityl-N.sup.G -trityl arginine within a process for preparing N.sup..alpha. -fluorenylmethoxycarbonyl-N.sup.G -trityl-arginine from arginine, comprising:a) forming N.sup..alpha. -trityl-N.sup.G -trityl-arginineb) selectively detaching the trityl group from the .alpha.-NH.sub.2 andc) introducing the fluorenylmethoxycarbonyl group in its place.The improvement consists of preparing the N.sup..alpha. -trityl-N.sup.G -trityl-arginine by solubilizing the arginine in an aprotic organic solvent by tri-alkylsilylation both of the amino nitrogen and of the carboxyl group, followed by tritylation, with trityl chloride, of the .alpha.-amino nitrogen, and of the guanidino group after deprotonating this latter with a bicyclic guanidine. The new improved process can also lead to variable quantities of the arginine analogue di-tritylated at the guanidino group, namely N.sup..alpha. -fluorenylmethoxycarbonyl-N.sup.G -di-trityl-arginine.

Abstract: Immunologically active polypeptide composition constituted by polypeptides having the formula:H--(Glu--Glu--Asn--Val--Glu--His--Asp--Ala).sub.n --OHwherein Glu=Glutamic Acid;Asn=Asparagine;Val=Valine;His=Histidine;Asp=Aspartic Acid;Ala=Alanineand wherein n has a value equal to, or larger than, 2.Said composition is useful for the preparation of antimalarial vaccines and of diagnostic kits for the detection of antimerozoite antibodies.

Abstract: A method of synthesis of a partially retro-inverso peptide incorporating at least one malonyl residue of formula (III) ##STR1## wherein R represents the side chain of an .alpha.-amino acid, is described which is characterized in that said malonyl residue is incorporated by condensing a 5-substituted-2,2-dimethyl-1,3-dioxane-4,6-dione of formula (IV) ##STR2## wherein R' is the side-chain R wherein the functional groups, if any, are suitably protected, with an amino acid, amino acid amide, peptide fragment, or pseudo-peptide fragment wherein the terminal carboxyl group, if present, and the possible side-chain functionalities are suitably protected and the reactive amino group is tri-alkyl-silylated.The new compounds of formula (VI) and a process for the preparation of a partially retro-inverso tuftsin analog which involves use of said method and said intermediate are also described and claimed.

Abstract: Synthetic peptides constituted by at least two repeating, consecutive units of asparaginyl-proline (Asn-Pro).sub.n sequence, are described.The peptides are powerful immunogens, capable of inducing in laboratory animals the formation of a high concentration of antibodies capable of reacting both with the (Asn-Pro).sub.n peptides, and with the immunodominant epitope of the circumsporozoite protein of Plasmodium falciparum.The peptides, which can be obtained in a pure form by chemical synthesis, are particularly useful for preparing antimalarial vaccines and diagnostic kits for the determination of malaria in man.

Abstract: New analogues of thymopentin (TP5) and of its tetrapeptide fragment (TP5.sup.1-4) containing two non-contiguous retro-inverted bonds in the peptide chain are described.The new compounds, of general formula (I) ##STR1## where R is hydrogen or an acyl radical, andR.sup.1 is an --OR.sup.2 group or an ##STR2## group where R.sup.2 is a hydrogen atom or a hydrocarbon radical, and R.sup.3 is a hydrogen atom or a hydroxyl group,and the corresponding pharmaceutically acceptable salts of acid or basic addition, possess immunomodulating activity.

Abstract: An improvement is described in the synthesis method for N.sup..alpha. -trityl-N.sup.G -trityl arginine within a process for preparing N.sup..alpha. -fluorenyl-methoxycarbonyl-N.sup.G -trityl-arginine from arginine, comprising:a) forming N.sup..alpha. -trityl-N.sup.G -trityl-arginineb) selectively detaching the trityl group from the .alpha.-NH.sub.2 andc) introducing the fluorenylmethoxycarbonyl group in its place.The improvement consists of preparing the N.sup..alpha. -trityl-N.sup.G -trityl-arginine by solubilizing the arginine in an aprotic organic solvent by tri-alkylsilylation both of the amino nitrogen and of the carboxyl group, followed by tritylation, with trityl chloride, of the .alpha.-amino nitrogen, and of the guanidino group after deprotonating this latter with a bicyclic guanidine. The new improved process can also lead to variable quantities of the arginine analogue di-tritylated at the guanidino group, namely N.sup..alpha. -fluorenylmethoxycarbonyl-N.sup.G -di-trityl-arginine.

Abstract: A method of synthesis of a partially retro-inverso peptide incorporating at least one malonyl residue of formula (III) ##STR1## wherein R represents the side chain of an .alpha.-amino acid, is described which is characterized in that said malonyl residue is incorporated by condensing a 5-substituted-2,2-dimethyl-1,3-dioxane-4,6-dione of formula (VI) ##STR2## wherein R' is the side-chain R wherein the functional groups, if any, are suitably protected, with an amino acid, amino acid amide, peptide fragment, or pseudo-peptide fagment wherein the terminal carboxyl group, if present, and the possible side-chain functionalities are suitably protected and the reactive amino group is tri-alkyl-silylated.The new compounds of formula (VI) and a process for the preparation of a partially retro-inverso tuftsin analog which involves use of said method and said intermediate are also described and claimed.

Abstract: Tripeptides having hypotensive activity, defined by the following general formula:A--B--C--OZ (I)wherein:A represents a residue of L-pyroglutamic acid, L-proline of L-proline bearing a substituent on its amino group ##STR1## wherein R.sub.1 is an acyl with a number of carbon atoms in straight chain not higher than 9, a benzyloxycarbonyl group or an alkyloxycarbonyl group;B is an .alpha.-aminoacide residue derived from one of the natural aminoacids;C is a residue of L-tryptophan (Trp), of L-phenylalanine (Phe) or of L-tyrosine (Tyr);Z is a hydrogen atom or an alkyl group with a number of carbon atoms in straight chain not higher than 9.

Abstract: An immunoenzimatic method is disclosed for the detection and the measurement of anti-P. falciparum sporzoite antibodies in human blood and/or in its derivatives, which operates with a synthetic antigen-enzyme conjugate capable of forming with the antisporozoite antibodies a stable antibody-synthetic antigen-enzyme complex, and one or more proteins absorbed and/or covalently linked to a solid support, which eagerly bind the antisporozoite antibody of said complex.The method, thanks to its simpleness, specificity and rapidity, is particularly useful in epidemiologic investigations into malaria and into the efficacy of an antimalarial vaccine.

Abstract: Synthetic peptides consisting of at least two consecutive repeating units of the sequence (Ala-Asn-Asn-Pro) are powerful immunogens in experimental animals.The antibodies which form recognize both said synthetic peptides and the immunodominant epitope of the circumsporozoitic peptide of Plasmodium falciparum.Said peptides, obtainable in pure form, are particularly useful for preparing antimalarial vaccines and diagnostic kits for the determination of malarial affections.

Abstract: The present invention refers to a new class of malonic acid derivatives of general formula I ##STR1## wherein R.sup.1 and R.sup.2, each independently, represent hydrogen or a carboxyl protecting group, and the residue R corresponds to the side-chain of the amino acids lysine, ornithine, tyrosine, cysteine, asparatic acid and glutamic acid wherein the additional functionalities are suitably protected. The new compounds of the present invention are useful for preparing analogues of biologically active peptides wherein the direction of some amide bonds in which the amino acids lysine, ornithine, tyrosine, cysteine, aspartic acid or glutamic acid are involved, has been reversed.