2A1 



Helen M. Habermann 



SUMMARY 



The increase in allagochrome values of leaves when chlorogenic 

 acid is added to the extracting medium strongly indicates that 

 this pigment is a chlorogenic acid derivative. 



An inhibition of the secondary synthesis of allagochrome from 

 chlorogenic acid by cyanide or heat treatment of leaves is consis- 

 tent with the hypothesis that this synthesis is mediated by an en- 

 zyme of the polyphenol oxidase type. The reduction of allago- 

 chrome values in plants deficient in copper adds further support 

 to this hypothesis. 



Estimated molecular weight of allagochrome based on analytical 

 ultracentrifuge studies is 720. NMR and infrared spectra indicate 

 that allagochrome and the yellow pigments fractionated from it 

 during purification are closely related chemically. ESR spectra 

 showed a free radical signal at g=2.005. 



It remains to be determined whether allagochrome is present in 

 vivo or is formed by the enzymatic oxidation of chlorogenic acid 

 during grinding. Present evidence supports the hypothesis that at 

 least part of the assayed amounts of this pigment could be present 

 before extraction. 



ACKNOWLEDGEMENTS 



I am indebted to Drs. Ulrich Weiss, Marc S. Lewis and Chester 

 DeLong of the Laboratory of Physical Biology, Institute of Arthri- 

 tis and Metabolic Diseases, National Institutes of Health, for 

 analytical ultracentrifuge, electron spin resonance and nuclear 

 magnetic resonance data. Dr. H. Knorr of the Charles F. Ketter- 

 ing Research Laboratory, Yellow Springs, Ohio, kindly did infra- 

 red absorption measurements. 



These studies were supported by grants from the National Sci- 

 ence Foundation (G-12757) and the U.S. Public Health Service (GM 

 07659-03). 



LITERATURE CITED 



1. Black, C.C., A. San Pietro, D. Limbach and G. Norris. Proc . 

 Nat. Acad. Sci. U.S. 50:37-43 (1963). 



2. Garrick, L.S. and H.M. Habermann. Am. J. Botany. 49:1078- 

 1088 (1962) . 



3. Ginsberg, A., P. Appel and H.K. Schachman . Arch. Biochem. & 

 Biophys. 65:545-566 (1956). 



