Abstract: A peptide optionally in isosteric form wherein a methylene group in the backbone chain is disubstituted, one or both substituents being fluorine and/or chlorine, in free form or in pharmaceutically acceptable salt form, such as a compound of formula I ##STR1## wherein the substituents have various significances, or an isosteric form thereof,is useful as an enzyme inhibitor. In particular, as a renin inhibitor, it is useful in the prophylaxis or treatment of hypertension and congestive heart failure.It is prepared by a process comprising the step of coupling two corresponding peptide residues optionally in isosteric form, or precursors thereof, and if required appropriately converting any resultant compound in precursor form.

Abstract: Described bare 3-halovinylglycines and their amino acid dipeptide and oligopeptide conjugates, a new class of efficient antibacterial agents, pharmaceutical compositions containing them as active ingredients, and methods of synthesis. The compounds are thought to interfere in bacterial cell wall synthesis.

Abstract: Described are 3-halovinylglycines and their amino acid dipeptide and oligopeptide conjugates, a new class of efficient antibacterial agents, pharmaceutical compositions containing them as active ingredients, and methods of synthesis. The compounds are thought to interfere in bacterial cell wall synthesis.

Abstract: The subject invention relates to novel cyclopropanone hydrate derivatives of the structural formula ##STR1## whereinR.sub.1 and R.sub.2 are selected from the group consisting of --H, --(CH.sub.2).sub.n -- where n is an integer between 1 and 20, preferably 2 and 10, --COCH.sub.2 NH.sub.2, and ##STR2## and R.sub.3 and R.sub.4 selected from the group consisting of --H, --OH, 13 NH.sub.2, --CN, --COOR.sub.5, --COOH, --SH, --(CH.sub.2).sub.n OH, --(CH.sub.2).sub.n NH.sub.2, --(CH.sub.2).sub.n COOH, --(CH.sub.2).sub.n COOR.sub.5, --CCH.sub.3 OH (CH.sub.2).sub.n COOH, halogen and C.sub.7 -C.sub.10 arakyls, where n is an integer between 1 and 20, preferably 1 and 10, and R.sub.5 is an alkyl radical having between 1 and 20, preferably 1 and 10, carbon atoms;and to a process for the synthesis thereof.