DERIVATIVES OF COMPLEX DIETHYLENETRIAMINEPENTANE ACETIC ACID

Compounds of the general formula in which Z and Z each represent a hydrogen atom or the radical -(CH2)m-(C6H4)q-(O)k-(CH2)n(C6H4) l-(O)r-R, in which m and n denote the figures 0 - 20, k, l, q and r denote the figures 0 and 1 and R denotes a hydrogen atom, an unsubstituted or OR -substituted C1-C6-alkyl radical or a CH2COOR group where R denotes a hydrogen atom, a C1-C6-alkyl radical or a benzyl group, X represents a hydrogen atom and/or a metal ion equivalent of an element of atomic number 21 - 29, 42, 44 or 57 - 83, with the proviso that at least two of the substituents X represent a metal ion equivalent in which one of the substituents Z and Z represents a hydrogen atom and the other does not represent a hydrogen atom, in which - if n and l each represent the figure 0 - k and r do not simultaneously each denote the figure 1, in which Z or Z do not represent -CH2-C6H4-O-CH2-COOCH2C6H5 or CH2-C6H4-O-(CH2)5-COOCH2C6H5 and in which -(O)r-R does not represent -OH, and their salts with inorganic and/or organic bases, amino acids or amino acid amides, are useful pharmaceutical agents.