Abstract: | Compounds of the formula ##STR1## in which R.sub.1 is an aliphatic hydrocarbon radical which is unsubstituted or substituted by halogen or hydroxyl, or a cycloaliphatic or araliphatic hydrocarbon radical; X.sub.1 is CO, SO.sub.2, or --O--C(.dbd.O)-- with the carbon atom of the carbonyl group being attached to the nitrogen atom shown in formula I; X.sub.2 is a divalent aliphatic hydrocarbon radical which is unsubstituted or substituted by hydroxyl, carboxyl, amino, guanidino or a cycloaliphatic or aromatic radical, or is a divalent cycloaliphatic hydrocarbon radical, it being possible for a carbon atom of the aliphatic hydrocarbon radical to be additionally bridged by a divalent aliphatic hydrocarbon radical; R.sub.2 is carboxyl which, if desired, is esterified or amidated, substituted or unsubstituted amino, formyl which, if desired, is acetalized, 1H-tetrazol-5-yl, pyridyl, hydroxyl which, if desired, is etherified, S(O).sub.m --R where m is 0, 1 or 2 and R is hydrogen or an aliphatic hydrocarbon radical, alkanoyl, unsubstituted or N-substituted sulfamoyl or PO.sub.n H.sub.2 where n is 2 or 3; X.sub.3 is a divalent aliphatic hydrocarbon; R.sub.3 is carboxyl, 5-tetrazolyl, SO.sub.3 H, PO.sub.2 H.sub.2, PO.sub.3 H.sub.2 or haloalkylsulfamoyl; and the rings A and B independently of one another are substituted or unsubstituted; in free form or in salt form, can be prepared in a manner known per se and can be used, for example, as medicament active ingredients. |