Cantharidin is an odorless, colorless fatty substance of the terpenoid class, which is secreted by many species of blister beetles. In its natural form, cantharidin is secreted by the male blister beetle, and given to the female as a copulatory gift during mating.
Afterwards, the female beetle covers her eggs with it as a defense against predators. Poisoning from cantharidin is a significant veterinary concern, especially in horses, but it can also be poisonous to humans if taken internally where the source is usually experimental self-exposure. Externally, cantharidin is a potent vesicant blistering agent , exposure to which can cause severe chemical burns.
Properly dosed and applied, the same properties have also been used therapeutically, for instance, for treatment of skin conditions, such as molluscum contagiosum infection of the skin.
Cantharidin is classified as an extremely hazardous substance in the United States , and is subject to strict reporting requirements by facilities that produce, store, or use it in significant quantities. Cantharidin, from the Greek kantharis , for beetle, [ 4 ] is an odorless, colorless natural product with solubility in various organic solvents, [ specify ] but only slight solubility in water. The complete mechanism of the biosynthesis of cantharidin is unknown.
Its framework formally consists of two isoprene units. Instead, there is a farnesol carbon precursor from which certain carbon segments are later excised. The level of cantharidin in blister beetles can be quite variable.
