| abstract |
This invention relates to new benzoxazinedione derivatives of general formula I, and conjugates thereof with active ingredients e.g. antibiotics. The compounds according to the invention constitute heterocyclically protected catechol derivatives and are effective as siderophores against gram-negative bacterial strains, particularly against Pseudomonads and strains of E. coli and Salmonella. In the form of their conjugates with active ingredients, e.g. antibiotics (as "siderophore-antibiotic conjugates"), they can transport the latter into bacterial cells and can improve or extend the antibacterial effect thereof, sometimes even in relation to bacterial strains which are resistant to other .beta.-lactams. In addition, said compounds, as potential prodrug forms for iron chelating agents, are suitable for use against diseases which are caused by a disorder of the iron metabolism. The invention can be employed in pharmaceutical research and in the pharmaceutical industry, and in agriculture. (See fig. I) wherein R1 = H or carboxyalkyl, R2 = H, alkyl or phenyl, and R3 represents different acid groups derived from amino acids, dipeptides and hydrazones or conjugates thereof with active ingredients, e.g. antibiotics. Said compounds may be present as free acids, in the form of their salts or as readily cleavable esters. |