Ditercalinium is the antineoplastic agent. Ditercalinium itself is not a natural product, however, it is derived from the natural product 5,11-dimethyl-6H-pyrido-[4,3- b]carbazole (ellipticine) that was isolated in 1959. It is a rare example of a noncovalent DNA-binding ligand that forms bisintercalation complexes via the major groove of the double helix. Ditercalinium selectively recognizes certain GC-rich sequences in DNA. It preferentialy binds with antiparallel quadruplex sequence d(AG(3)[T(2)AG(3)](3)). Ditercalinium chloride can deplete mitochondrial DNA in both mouse and human cells. Ditercalinium chloride inhibits human DNA polymerase gamma activity as efficiently as does ethidium bromide. Ethidium bromide distributes diffusely in the mitochondria of HeLa cells, while ditercalinium chloride distributes granularly and hence may be strongly associated with mitochondrial DNA.