Abstract: This invention relates to new peptide derivatives of the general formula (I) A-Xaa-Arg-H, wherein A represents a D- or L-isochroman-1-carbonyl, D- or L-isochroman-3-carbonyl group, furthermore an acyl group of the general formula: D- or DL-A'--CH(OH)--CO, wherein A' represents a phenyl, benzyl, 1-naphthyl, 1-naphthylmethyl, 2-naphthyl, 2-naphthylmethyl, 9-fluorenyl, benzhydryl, cyclohexyl, cyclohexylmethyl, 2-pyridyl, 3-pyridyl or 4-pyridyl group, and Xaa represents an L-prolyl or an L-pipecolinic acid residue, and Arg stands for an L-arginine residue, their acid addition salts formed with an organic or inorganic acid and pharmaceutical compositions containing the same. Furthermore the invention relates to a process for preparing them. The compounds of the invention have valuable therapeutic, particularly anticoagulant, properties.

Abstract: The invention relates to new peptide-aldehydes and a process for the preparation thereof, furthermore to pharmaceutical compositions containing the same.According to a feature of the present invention there are provided new peptide-aldehyde derivatives corresponding to the general formula (I) ##STR1## wherein R.sub.1 represents hydrogen or C.sub.1-6 alkyl group,R.sub.2 stands for C.sub.1-6 alkyl group, furthermore R.sub.1 and R.sub.2 are linked to the amino group of the Xxx alpha-amino acid,Xxx represents a D-phenylalanine residue or a D-alpha-amino acid group having in the side chain a C.sub.1-4 alkyl group,Pro stands for L-proline residue,Yyy stands for L-, D- or DL-arginine residue andA represents an acid residue.The new peptide-aldehyde derivatives of the invention possess valuable anticoagulant activity.

Abstract: The invention relates to t-butyloxy-carbonyl-D-phenylalanyl-L-prolyl-L-arginine aldehyde hemisulfate and D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate, which is highly stable in aqueous solution, and to a process for preparing D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate from D-phenylalanyl-L-prolyl-L-arginine aldehyde hemisulfate or N.sup.G -carboxy derivative containing an acid-sensitive protecting group at its amino terminal, wherein the acid sensitive amino terminal protecting group or optionally the N.sup.G -carboxy group is removed with 1 to 12 N sulfuric acid, applied in 1 to 12 equivalent amounts and the resulting free tripeptide aldehyde sulfate isolated. The D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate of the invention possesses valuable anti-coagulant activity.

Abstract: The invention relates to D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate, highly stable in aqueous solution, and to a process for preparing it from D-phenylalanyl-L-prolyl-L-arginine aldehyde hemisulfate or N.sup.G -carboxy derivative containing an acid-sensitive protecting group at its amino terminal, wherein the acid sensitive amino terminal protecting group or optionally the N.sup.G -carboxy group is removed with 1 to 12 N sulfuric acid, applied in 1 to 12 equivalent amounts and the resulting free tripeptide aldehyde sulfate is isolated. The D-phenylalanyl-L-prolyl-L-arginine aldehyde sulfate of the invention possesses valuable anticoagulant activity.

Abstract: Anti-coagulants of the formula X-Pro-Agm(HB) (.sub.n) whereinX is an alpha-amino acid moiety of the configuration having a phenyl, phenyl-(lower)-alkyl or phenyl-(heteroatom-containing) lower alkyl side chain,Agm is an agmatine group (1-amino-4-guanidino-butane),B is an acid residue, andn is an integer from 0-2, are disclosed.

Abstract: Novel peptidyl-arginine aldehyde derivatives and their salts of formula I, ##STR1## wherein X represents a hydrogen atom, benzoyl or tert-butyloxycarbonyl group, and Y is a D-phenylalanine, .beta.-phenyl-D-lactic acid or D-allo-isoleucine moiety, are prepared from peptidyl-arginine aldehydes protected by an urethane type protecting group on their N- or O-terminal and/or a guanidino group, by removing the protecting group in a mixture of lower alkanols and water by means of hydrogenolysis, and eventually converting the product formed into a salt.The compounds of formula I possess valuable antithrombin activity.