Saponin

A poisonous glucoside found in many plants as in the root of soapwort Saponaria in the bark of soap bark Quillaia etc It is extracted as a white amorphous powder which occasions a soapy lather in solution and produces a local anaeligsthesia Formerly called also struthiin quillaiin senegin polygalic acid etc By extension any one of a group of related bodies of which saponin proper is the type