Abstract: The invention relates to a process for the preparation of carboxamides, in particular peptides, from an acid component in the form of a compound containing at least one carboxyl group and an amine component in the form of a compound containing at least one primary or secondary amino group, and its use.

Abstract: The present invention relates to peptides, which are useful in treating Staphylococcus infections. More particularly, the inventive peptides interfere with the regulation of the agr system of Staphylococcus species, especially S. aureus, and thereby block the formation of different virulence factors. The inventive peptides comprise at least the amino acid sequence S V X A S Y F, whereby cyclic structures of that kind of peptides are the most potent blocking reagents.

Abstract: The invention concerns novel lipid compounds suitable for the transport of biologically active substances or molecules in cells. A preferred compound according to the invention is L-lysine-bis-(O,O′-cis-9-octadecenoyl-&bgr;-hydroxyethyl)-amide dihydrochloride or one of its optical isomers. In addition, the invention concerns complexes of the novel lipid compounds with polyanions such as DNA and RNA, and ternary complexes of the novel lipid compounds with polyanion and polycations. Finally, the invention concerns liposome formulations made from biologically active substances and the novel lipid compounds, as well as methods of transporting polyanions, polycations or biologically active substances through biological membranes by means fo the novel lipid compounds.