It consists of two parts, a labile chromophore (bicyclic dienediyne structure shown at right) and a 113 amino acid apoprotein to which the chromophore is tightly and non-covalently bound with high affinity (Kd ~ 10-10 M). The chromophore is a very potent DNA-damaging agent; it is very labile and the role of the apoprotein is to protect it and release it to the target DNA. Opening of the epoxide under reductive conditions present in cells creates favorable conditions for a Bergman cyclization, leading to a diradical intermediate and eventually double DNA strand cleavage. Other members of the neocarzinostatin group of antibiotics are macromomycin, actinoxanthin, kedarcidin and maduropeptin.
As a medicine it is among the most potent, and in Japan only it has been used against liver cancer clinically.