Allagochrome. I. Properties, Purification, & Assay Procedures.

Allagochrome3 is a water-soluble pigment which has been extracted from the leaves of a number of species of higher plants. Attempts to purify and characterize allagochrome have revealed that the apparently uniform fraction obtained following electrophoresis and chromatography on sephadex has at least three distinct but tightly bound components: 1) a chromophoric group absorbing in the red with a peak at approximately 670 m,u, 2) copper, and 3) a fluorophoric group emitting at 460 my when excited by ultraviolet light. The most conspicuous of the three is, of course, the chromophoric group which is responsible for the characteristic blue-green appearance and the striking color changes of allagochrome solutions in response to oxidation or reduction and pH. When allagochrome was first described (3), no records had been found in the literature of this or comparable compounds from leaves. Since that time it has been learned that in 1950 Kozlowski, working in Hill's laboratory, had reported the formation of a green oxidation-reduction inclicator in plant extracts (7). Also. Kahn, Dorner, and Wildman in the mid to late 1950's extracted and attempted to purify a green compound from tobacco and artichoke which appears to have been allagochrome. The attempts of the latter workers to purify and characterize their green stuff were not completely successful and were never published (private communication, Dr. R. W. Dorner). A copper protein extracted from Chlorella cllipsoidea with properties similar to allagochrome has recently been reported by Katoh (6). These two pigments are not identical spectrophotometrically, however, and the conoer protein from Chlorella is not autoxidizable. All assays of Chlorella pyrenoidosa for allagochrome have been negative. Substances with similar spectra and electrochemical properties have been extracted from spinach chloroplasts by Takamatsu and from chloroplasts of Chrvsanthenznmiwtt coronariumsl by Katoh (6). It is quite possible that the preparation from Chrysanthemum is allagochrome because we have found that Chrysanthemum species