COCARCINOGEN FROM C ~ o t o ntigliurn L.
September 1965
hydrocarbon. At the low concentration used the hydrocarbon, when applied alone, is inactive and croton oil itself is not carcinogenic. This unique activity of croton oil has important implications in studies of cancer causation and many attempts have been made to isolate and determine the structure of the active compolient s.5-g The seed of Croton tigliunz L. was extracted with methyl alcohol to given an oily extract. This extract has vesicant, toxic, irritant, and tumor-enhancing activities. The separation and isolation of the crystalline active principle from all the other components from croton resin (about eight noncrystalline fractions, all with similar infrared spectra) was hampered by the fact that these compounds were held together by strong polar interactions which were not broken by solvent partition and column Chromatography. The complete separation and isolation of the crystalline, active, principle compound C-3 (I) was finally accomplished
HO
