Page 201 - Phytochemistry 2 (06-PG 605)

IV- Anhydride bitter

Cantharidin (Cantharides Camphor).

Sources: It is the active principle of the dried insect,
Cantharis vesicatoria, Family Meloidae and other insects

Cantharidin is liberated by treatment with acid from its salts present
in powdered insects.

Identification Tests :
Formaldehyde Test:crystals of cantharidin + 1-2 drop of dilute
sulfuric/formaldehyde solution, warm→brown to black colour.
Uses
Rubifacient and counter irritant .