A NEW MICRO COLOR REACTION OF CANTHARIDIN

A new and specific micro color reaction of cantharidin,tesed in 54 compounds including 22 alkaloids,12 amines,14 phenols,santonin,coumarin,barbital,pheno- barbital,urea and sulfonal(Tab.1) is considered to be simple,rapid and sensitive, by the following proposed procedure.In a small test tube(0.7×7cm),dissolve a minute amount of cantharidin in 1-2 drops of H₂SO₄(Sp.gr.1.77) by warming, continue the heat with a small flame and,as soon as some bulbs begin to evolve, add 1 drop of p-dimethylaminobenzaldehtde sulfuric acid solution(0.1g in 4 ml H₂O+4ml H₂SO₄) after taking the test tube away from the flame.A yellow color appears but changes to pink immediately and the maximum absorption of the Pink color in the clear and transparent solution is 536 mu.The sensitivity is 5γ for cantharidin. "pan Mao" from market may be extracted by chloroform acidified with HCL, filtered and evaporated to dryness on a water bath below 60°.The residue May be purified either by chromatography on alumina column obtaining cantharidin as white powdered crystals or by recrystallizing from alcohol-petroleum ether mixture with the yield of brownish white prism crystals.Test a minute amount of the cry- stals by the procedure mentioned above a beautiful and distinct pink color would finally appear. "Pan Mao" or Cantharidin,added to the pig stomach and its contents,and treated with petroleum ether to eliminate part of oil and fats,may be extracted accord- ingly. Dissolve the chloroform extract residue in hot acetone,cool,then separate the acetone from the fat and oil by gentle decantation,and drive off the.acetone by evaporation.The residue is rinsed with petroleum and crystals in needle form may be obtained.A sensitive and prominent test for Cantharidin may be obtained with a minute amount of the crystals by the propOsed proposed procedure mentioned above.