The integration of a selective Hg²⁺ receptor unit, 1,4-dioxa-7,13-dithia-10-azacyclopentadecane, into the 9-aminoacridizinium fluorophore provides a fluorescent probe which allows a selective ratiometric detection of Hg²⁺ in water.

DNA intercalators represent an important class of compounds with a high potential as DNA‐targeting drugs. In this review it is demonstrated that annelated quinolizinium derivatives such as coralyne and derivatives thereof intercalate into DNA and that this structural motif allows several variations of the substitution pattern without loss of intercalating properties. The commonly applied methods for the evaluation of the DNA association, mainly spectroscopic studies, are pointed out. In addition, studies on the biological activities of annelated quinolizinium derivatives, such as topoisomerase poisoning or cell toxicity, are highlighted.