Styrylquinolines, perhaps among the newest anticancer agents, are not easily placed in any classification. These compounds are more precisely derivatives of p-( dimethyl-ammo )-4-quinolyl styrene (LXXV). The fact that planarity is not essential for anti-tumor activity implies that the effect may be due to either the quinoline or styrene moieties. It would be possible to predict that the molecule is biologically hydroxyl-ated in the 2-position to give a 2-hydroxyquinoline derivative (LXXVI) which would not be a good chelating compound. The N-oxide of this molecule could chelate metals. A better chelating agent would be the 8-hydroxyquinoline derivative, which has not as yet been evaluated. The 2-styryl-8-hydroxy quinoline isomer (LXXVII) has been synthesized recently but not tested.

(LXXV)

(LXXVI)

The mechanism of action of these styryls is not known. They may, like the azo dye anticancer molecules, act like open models of hydrocarbons. This would imply that the cis isomer (LXXVIII) would be more effective than the trans, and that perhaps a naphthylquinoline styryl derivative may even be better.

One study did show that styrylquinoline appeared to accelerate the agglutination of rat liver mitochondria incubated in the presence of magnesium ions. This styrylquinoline stimulated the magnesium-dependent ATP-ase activity.