Cantharides

Cantharidin

Names
IUPAC name 2,6-Dimethyl-4,10-dioxatricyclo-[5.2.1.02,6]decane-3,5-dione
Other names Cantharidin, Spanish Fly
Identifiers
CAS Number	56-25-7 N
3D model (JSmol)	Interactive image
ChemSpider	2297293 Y
ECHA InfoCard	100.000.240
KEGG	C16778 N
UNII	IGL471WQ8P Y
InChI InChI=1S/C10H12O4/c1-9-5-3-4-6(13-5)10(9,2)8(12)14-7(9)11/h5-6H,3-4H2,1-2H3/t5-,6+,9-,10+ Y Key: DHZBEENLJMYSHQ-YUMGAWCOSA-N Y
SMILES O=C2OC([C@@]1(C)[C@@H]3CC[C@@H](O3)[C@]12C)=O
Properties
Chemical formula	C10H12O4
Molar mass	196.20 g·mol−1
Density	1.41 g/cm3
Melting point	212 °C (414 °F; 485 K)
Hazards
Main hazards	Highly toxic
GHS pictograms
NFPA 704	1 4 1
Lethal dose or concentration (LD, LC):
LD50 (median dose)	0.03–0.5 mg/kg (human)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Cantharidin is an odorless, colorless fatty substance of the terpenoid class, which is secreted by many species of blister beetles. It is a burn agent or a poison in large doses, but preparations containing it were historically used as aphrodisiacs. 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 which produce, store, or use it in significant quantities.

Cantharidin, from the Greek kantharis, for beetle, is an odorless, colorless natural product with solubility in various organic solvents, but only slightly solubility in water. It is a monoterpene, and so contains in its framework two isoprene units derived by biosynthesis from two equivalents of isopentenyl pyrophosphate. The complete mechanism of the biosynthesis of cantharidin is unknown. Its skeleton is tricyclic, formally, a tricyclo-[5.2.1.02,6]decane skeleton. Its functionalities include an carboxylic acid anhydride (-CO-O-CO-) substructure in one of its rings, as well as a cyclic ether in its bicyclic ring system.