| abstract |
The invention relates to a condensation product obtainable by reaction ofn a1) at least one bicyclic or polycyclic aromatic or heteroaromatic, where the bicyclic or polycyclic aromatic or heteroaromatic is substituted by at least one carboxyl group (—COOH), and where the carboxyl group can be present in salt form, a2) at least one carbonyl compound, a3) if appropriate at least one sulfonating agent, a4) at least one urea derivative, and a5) if appropriate at least one further aromatic or heteroaromatic, or a physiologically tolerable salt thereof. |