STUDIES ON THE ANTITUMOR-ACTIVITY OF SOME IRON SANDWICH COMPOUNDS

Four types of water-soluble iron sandwich compounds, ferrocenes bearing charged side chains (Ia), ferrocenium salts (Ib). (eta-arene)2Fe2+ salts (II) and (eta-arene)(eta-cyclopentadienyl)Fe+ salts (III), have been tested in vitro against experimental tumours, L1210, Walkers and Chinese hamster lung (V.79). Some activity was observed for all the types of complex; though that of only two, Ib and II, was good. Of special interest is that the iron(II) sandwich type II compounds display anti-tumour activity, since previous active complexes have contained type Ib or other known cytotoxic groups that would account for their activity. Examples of complexes of type Ib and II were further tested against improved cell lines L1210, PC6 and CH1. The results show the two types to be similar in their effect and specificity. An attempt is made to rationalise the data.