Abstract: An amino acid derivative having anti-hypertensive activity and having the formula: ##STR1## wherein one of X or Y represents an acyl group RCO--, and wherein R is an amino acid residue selected from the group consisting of glycyl, alanyl, valyl, leucyl, isoleucyl, phenylalanyl, methionyl, prolyl, ceryl, threonyl, arginyl, lysyl, histidyl, aspartyl, asparaginyl, tyrosyl, cysteinyl, tryptophyl, and hydroxyprolyl, and the other group is H; R.sup.1 and R.sup.2 are the same or different from each other, and each represents H, lower alkyl having 1 to 6 carbon atoms, aryl having 6 to 12 carbon atoms, any of which are unsubstituted or substituted by one or more lower alkyl, lower alkoxy, hydroxy, amino, carboxy or mercapto groups; Z represents --OH, RO--, RS--, RNH--, NONH--, RONH--, RSO.sub.

Abstract: Peptides represented by the formula: ##STR1## wherein: X represents Met, Met(O), Nle, or Ile;Y represents a cystine residue or an .alpha.-amino suberic acid residue;Z represents Gly or Ala;m, n, and p each represent 0 or 1;A represents Ser, Ser-Ser, Arg-Ser-Ser, Arg-Arg-Ser-Ser, Leu-Arg-Arg-Ser-Ser, or Ser-Leu-Arg-Arg-Ser-Ser; andB represents Asn, Asn-Ser, Asn-Ser-Phe, Asn-Ser-Phe-Arg, or Asn-Ser-Phe-Arg-Tyr;with the proviso that .alpha.-hANP(1-28), .alpha.-rANP(1-28), .alpha.-rANP(4-28), .alpha.-rANP(5-27), .alpha.-rANP(5-25), and .alpha.-rANP(3-28) are excluded from the compounds represented by the formula are disclosed along with methods of using these compounds.

Abstract: The present invention relates to an amino acid derivative represented by the formula ##STR1## wherein R.sub.1 and R.sub.2 represent hydroxyl, alkyloxy, aryloxy, arylkyloxy, alkyl, aryl, or aralkyl; R.sub.3, R.sub.5, R.sub.8 and R.sub.11 are hydrogen or alkyl; R.sub.4, R.sub.7 and R.sub.10 are hydrogen, or substituted or unsubstituted alkyl, aryl or aralkyl; R.sub.6 and R.sub.9 are hydrogen, alkyl, aryl, or aralkyl; R.sub.12 is hydroxyl, alkyloxy, aryloxy, aralkyloxy, amino, mono- or di-alkyl-, aryl- or aralkyl amino; and R.sub.6 and R.sub.7 combined together, and R.sub.9 and R.sub.10 combined together independently may form a substituted or unsubstituted alkylene bridge. The present invention also relates to a method of preparing said amino acid derivatives, and to anti-hypertensive drugs containing them.

Abstract: N-terminal phosphorus dipeptides having antihypertensive properties are disclosed.

Abstract: The present invention relates to an amino acid derivative represented by the formula ##STR1## wherein R.sub.1 and R.sub.2 represent hydroxyl, alkyloxy, aryloxy, arylkyloxy, alkyl, aryl, or aralkyl; R.sub.3, R.sub.5, R.sub.8 and R.sub.11 are hydrogen or alkyl; R.sub.4, R.sub.7 and R.sub.10 are hydrogen, or substituted or unsubstituted alkyl, aryl or aralkyl; R.sub.6 and R.sub.9 are hydrogen, alkyl, aryl, or aralkyl; R.sub.12 is hydroxyl, alkyloxy, aryloxy, aralkyloxy, amino, mono- or di-alkyl-, aryl- or aralkyl amino; and R.sub.6 and R.sub.7 combined together, and R.sub.9 and R.sub.10 combined together independently may form a substituted or unsubstituted alkylene bridge. The present invention also relates to a method of preparing said amino acid derivatives, and to anti-hypertensive drugs containing them.

Abstract: A hentriacontapeptide of the formula (I) ##STR1## a radioactive labeled hentriacontapeptide of the formula (I), useful in a radioimmunoassay method and a radioimmunoassay method for determining calcitonin.

Abstract: A peptide derivative useful as substrates for determining enzymatic activities have the following formula ##STR1## wherein R.sub.1 is a group selected from the group consisting of seryl, phenylalanyl-seryl, threonyl and leucyl-threonyl groups, and R.sub.

Abstract: A peptide derivative having the formula: ##STR1## wherein R is a radical selected from the group consisting of hydrogen, glutamyl, isoleucyl-glutamyl, phenylalanyl-glutamyl, lysyl, glutamyl-lysyl, phenylalanyl-glutamyl-lysyl, leucyl, and valyl-leucyl. This compound is useful as a fluorescent substrate for the sensitive determination of enzymatic activity.

Abstract: Peptide derivatives useful as fluorogenic substrates for determining enzymatic activities have the following formula ##STR1## wherein Y is H or ##STR2## and X is a radical selected from the group consisting of ##STR3## wherein R is a radical selected from the group consisting of hydrogen, amino-protecting groups, amino acid residues, terminal amino-protected amino acid residues, oligopeptide residues and terminal amino-protected oligopeptide residues.

Abstract: The compound 7-glycylprolylamino-4-methylcoumarin and certain of its derivatives are utilized for the diagnosis of pathological conditions such as hepatic diseases and gastric cancer by measuring the enzymatic activity of X-prolyl dipeptidyl-aminopeptidase.

Abstract: The activity of X-prolyl dipeptidyl-aminopeptidase against X-L-proline-Y wherein X is an amino acid residue and Y is p-nitroaniline, p-phenylazoaniline or 4-phenylazo-1-naphthylamine is used as a measure of human afflictions such as hepatobiliary diseases and carcinomas.

Abstract: A method of measuring collagenase activity using as substrates peptide derivatives having the structure A-Pro-B-Gly-C-Ala-Gly-E wherein A is a hydrophobic neutral or acidic chromophore, B is an amino acid residue, C is Ile or Leu, E is Gln-D-Arg-OH or D-Arg-OH and all the amino acid residues except for Gly are L-configuration unless otherwise stated.

Abstract: The compound 7-glycylprolylamino-4-methylcoumarin and certain of its derivatives are utilized for the diagnosis of pathological conditions such as hepatic diseases and gastric cancer by measuring the enzymatic activity of X-prolyl dipeptidyl-aminopeptidase.

Abstract: Peptide derivatives are obtained by eliminating the masking groups from masked peptide derivatives in which the guanidino group of an arginine residue and the carboxyl group of the arginine residue are masked. The guanidino group can be masked, for example, with a tosyl, nitro or benzyloxycarbonyl group, and the carboxyl group can be masked by converting it to an ester group, for example, a benzyl or t-butyl ester group. The masking groups can be eliminated using hydrogen fluoride, for example.

Abstract: The activity of X-prolyl dipeptidyl-aminopeptidase against X-L-proline-Y wherein X is an amino acid residue and Y is p-nitroaniline, p-phenylazoaniline or 4-phenylazo-1-naphthylamine is used as a measure of human afflictions such as hepatobiliary diseases and carcinomas.

Abstract: Polypeptides of the formula ##STR1## wherein A.sub.1 is Ser or Gly, A.sub.7 is Val or Met, A.sub.10 is Lys or Thr, A.sub.11 is Leu or Tyr, A.sub.12 is Ser or Thr, A.sub.14 is Glu or Asp, A.sub.15 is Leu or Phe, A.sub.16 is His or Asn, A.sub.18 is Leu or Phe, A.sub.19 is Gln or His, A.sub.21 is Tyr or Phe, A.sub.23 is Arg or Gln, A.sub.25 is Asp or Asn or Ala, A.sub.26 is Val or Thr or Ile, A.sub.28 is Ala or Ser or Val, and A.sub.30 is Thr or Val or Ala, and pharmaceutically acceptable acid addition salts and complexes, have serum calcium reducing activity.