Abstract: There are described optically active derivatives of (R) 5-pentylamino-5-oxopentanoic acid and their pharmaceutically acceptable salts, having antagonistic activity towards cholecystokinin, and with the formula: ##STR1## in which R.sub.1 is selected from the groups 2-naphthyl, 3,4-dichlorophenyl and 3,4-dimethylphenyl and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 carbon atoms, and in which the substituents on the central chiral group (marked with an asterisk in Formula (I)), have the R (rectus) conformation.

Abstract: There are described optically active derivatives of (R) 5-pentylamino-5-oxopentanoic acid and their pharmaceutically acceptable salts, having antagonistic activity towards cholecystokinin, and with the formula: ##STR1## in which R.sub.1 is selected from the groups 2-naphthyl, 3,4-dichlorophenyl and 3,4-dimethylphenyl and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 carbon atoms, and in which the substituents on the central chiral group (marked with an asterisk in Formula (I)), have the R (rectus) conformation.

Abstract: There are described optically active derivatives (R) 5-pentylamino-5-oxopentanoic acid and their pharmaceutically acceptable salts, having antagonistic activity towards cholecystokinin, and with the formula: ##STR1## in which R.sub.1 is selected from the groups 2-naphthyl, 3,4-dichlorobenzoyl and 3,4-dimethylbenzoyl and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 carbon atoms, and in which the substituents on the central chiral group (marked with an asterisk in Formula (I)), have the R (rectus) conformation.

Abstract: New original derivatives are described of 5-pentylamino-5-oxopentanoic and 4-pentylamino-4-oxobutanoic acids having the formula: ##STR1## in which n is 1 or 2, R.sub.1 is selected from the groups 2-naphthyl, 2 (or 3)-quinolinyl, 2 (or 3)-indolyl, 2 (or 3)-benzofuranyl, 2 (or 3)-benzothiophenyl, and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 or 5 carbon atoms, preferably pentyl, 2-ethoxyethyl, 3-methoxypropyl or 3-ethoxypropyl.The compounds have a powerful antagonistic activity towards cholecystokinin and are particularly useful in the treatment of illnesses of the digestive system, such as colitis, biliary diskinesia, pancreatitis or in the treatment of disorders of the central nervous system imputable to deficiencies in the physiological neuron levels of cholecystokinin or other related bioactive polypeptides.

Abstract: New original derivatives are described of 5-pentylamino-5-oxopentanoic and 4-pentylamino-4-oxobutanoic acids having the formula: ##STR1## in which n is 1 or 2, R.sub.1 is selected from the groups 2-naphthyl, 2 (or 3)-quinolinyl, 2 (or 3)-indolyl, 2 (or 3)-benzofuranyl, 2 (or 3)-benzothiophenyl, and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 or 5 carbon atoms, preferably pentyl, 2-ethoxyethyl, 3-methoxypropyl or 3-ethoxypropyl.The compounds have a powerful antagonistic activity towards cholecystokinin and are particularly useful in the treatment of illnesses of the digestive system, such as colitis, biliary diskinesia, pancreatisis or in the treatment of disorders of the central nervous system imputable to deficiencies in the physiological neuron levels of cholecystokinin or other related bioactive polypeptides.

Abstract: New original derivatives are described of 5-pentylamino -5-oxopentanoic and 4-pentylamino-4-oxobutanoic acids having the formula: ##STR1## in which n is 1 or 2, R.sub.1 is selected from the groups 2-naphthyl, 2 (or 3)-quinolinyl, 2 (or 3)-indolyl, 2 (or 3)-benzofuranyl, 2 (or 3)-benzothiophenyl, and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 or 5 carbon atoms, preferably pentyl, 2-ethoxyethyl, 3-methoxypropyl or 3-ethoxypropyl.The compounds have a powerful antagonistic activity towards cholecystokinin and are particularly useful in the treatment of illnesses of the digestive system, such as colitis, biliary diskinesia, pancreatitis or in the treatment of disorders of the central nervous system imputable to deficiencies in the physiological neuron levels of cholecystokinin or other related bioactive polypeptides.

Abstract: N-acylated derivatives of L-tryptophan of general formula (I), ##STR1## in which R is selected from the group consisting of: (a) a phenyl group, mono-substituted or di-substituted in the meta and para positions with halogens, linear or branched alkyl groups containing from 1 to 9 carbon atoms, the cyano group or the trifluoromethyl group, (b) a benzyloxy group, mono-substituted or di-substituted in the meta and para position with substituents selected from those indicated at (a), and (c) a benzydryloxy group. The derivatives are used in therapy, particularly for human pain relief, in the treatment of pathological conditions of the central nervous system and of pathological intestinal conditions.

Abstract: New original derivatives are described of 5-pentylamino-5-oxopentanoic and 4-pentylamino-4-oxobutasnoic acids having the formula: ##STR1## in which n is 1 or 2, R.sub.1 is selected from the groups 2-naphthyl, 2 (or 3)-quinolinyl, 2 (or 3)-indolyl, 2 (or 3)-benzofuranyl, 2 (or 3)-benzothiophenyl, and R.sub.2 is a pentyl group or an alkoxyalkyl group with 4 or 5 carbon atoms, preferably pentyl, 2-ethoxyethyl, 3-methoxypropyl or 3-ethoxypropyl.The compounds have a powerful antagonistic activity towards cholecystokinin and are particularly useful in the treatment of illnesses of the digestive system, such as colitis, biliary diskinesia, pancreatitis or in the treatment of disorders of the central nervous system imputable to deficiencies in the physiological neuron levels of cholecystokinin or other related bioactive polypeptides.

Abstract: New derivatives of D,L-glutamic acid and D,L-aspartic acid are described having the formulae: ##STR1## in which n is equal to 1 or 2, R.sub.1 is a phenyl group mono-, di- or tri-substituted with linear or branched C.sub.1 -C.sub.4 alkyl groups, which may be the same or different, or with halogens, with a cyano group or a trifluoromethyl group, and in which R.sub.2 is selected from the group consisting of morpholino, piperidino and amino with one or two linear, branched or cyclic alkyl group substituents containing from 1 to 8 carbon atoms, which may be the same or different, or a pharmaceutically-acceptable salt thereof.The compounds have an antagonistic activity towards bioactive polypeptides and are useful particularly in the treatment of illnesses of the digestive system and the central nervous system, as pain killers, and for the treatment of anorexia and all those affections (for example tumours) in which exogenous or endogenous bioactive polypeptides are involved.

Abstract: New Orginal derivates of D,L-glutamic acid and D,L-aspartic acid are described having the formula: ##STR1## where n is 1 or 2, R.sub.1 is a mono- or di-substituted phenyl group substituted with halogens such as chlorine and fluorine or with a methyl group in the 3 and 4 positions and in which R.sub.2 consists of a linear or branched alkyl group with 4 to 7 carbon atoms (preferably a pentyl group) and R.sub.3 is an alkyl group having 3 to 6 carbon atoms overall and containing an oxygen atom in the form of an either linkage, such as for example the groups 2-ethoxyethyl, 3-methoxypropyl, 3-ethoxypropyl etc. or in the form of a hydroxyl group such as for example 3-hydroxypropyl etc.The compounds have antagonistic activity towards bio-active polypeptides and are usable particularly in the treatment of illnesses of the digestive tract, of the central nervous system and anorexia and of all those affections (for example tumours) in which exogenic or endogenic bio-active polypeptides are involved.