[Synthetic inhibitors of serine proteinases. Part 21: Studies on the structure-activity relationships in bisamidines (author's transl)].

The antitrypsin, antiplasmin and antithrombin activities of bis(amidinobenzylidene)- and bis(amidinobenzyl)cycloalkanones are not markedly affected if the amidino group is substituted by an uncharged residue (H, OCH3, Cl, Br, NO2). In contrast, mono(amidinobenzylidene)cycloalkanones exhibit considerably lower inhibitory activities than the compounds of the abovementioned classes of substances. From the results obtained it is concluded that the second aromatic residue and not the second basic amidino group is decisive of the potent inhibitory action of the bisamidino derivatives.