Abstract: Claimed are a compound of the general formula (I) and pharmaceutically acceptable salts thereof, where M signifies metal atoms selected independently from the group comprising Pd, Fe, Mn, Co, Ni, Cu, Zn and Mo; R1 and R2, independently of each other, signify hydrogen, amino, hydroxy, oxy, carboxy, cyano, C1-12alkyl, C2-12alkenyl, C2-12alkynyl, C1-12alkoxy, C1-12alkylamino, C1-12alkoxycarbonyl, C1-12alkylamido, arylamido, wherein the alkylene groupings in the given substituents can in turn be substituted by one or more of the following groups: hydroxy, oxy, carboxy, amino or amido; R3-R10, independently of each other, signify hydrogen; or NHR3R4 and NHR5R6, taken together, and/or NHR7R8 and NHR9R10, taken together, are a ligand (or ligands) containing one or several donor aliphatic or aromatic atoms of nitrogen and being in cis position on the metal atoms (M).