A series of analogues of amsacrine have been prepared by replacing the acridine with a variety of other chromophores, in a search for 'minimal' DNA-intercalating anti-tumour agents which might show superior distributive properties as a consequence of lower levels of binding to cellular macromolecules. 2-Styrylquinoline derivatives did show in vivo anti-leukaemic activity, but none of the compounds was superior to amsacrine itself.