Ophiobolin A is a phytotoxin that causes electrolyte and glucose leakage in plants, inhibits root growth, and induces other related effects. Ophiobolin A is a potent, Ca2+-dependent, irreversible calmodulin inhibitor. Ophiobolin A covalently targets mitochondrial complex IV, leading to mitochondrial hyperactivity, dissipation of membrane potential, and ultimately a sharp collapse of ATP production and rapid cell death. Ophiobolin A can be used in phytotoxin and cancer research[1][2][3].