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Helen M. Habermann 



ions are not present in purified preparations of the pigment. 

 However, direct chemical analyses of allagochrome had indicated a 

 low but persistent Cu content. These results excluded the possi- 

 bility that allagochrome might contain Cu++ . They also proved 

 that the color changes of allagochrome, especially its reversible 

 reduction, cannot be accounted for on the basis of copper but must 

 rather be accounted for by a probably quinonoid chromophoric group, 



ESR signals of the type obtained previously only in the solid 

 have been obtained recently in solution - probably because of in- 

 creased allagochrome concentration (50 mg/ml vs. 2 mg/ml) . This 

 is a free radical signal with some fine structure and present in 

 very low concentrations. The molecule is not all in a free radi- 

 cal form but seems in a state of constant presence of a small a- 

 mount of free radical. With more concentrated preparations there 

 is a small but recognizable +3 iron signal. No studies have yet 

 been made of the possible effects of light on the ESR signals of 

 allagochrome . 



Nuclear magnetic resonance 



Table I summarizes information from NMR spectra of a series of 

 pigments and derivatives prepared from Helianthus leaves. 



Table I 



It seems probable that all of these compounds except 5 are 

 closely related and may be derivatives of breakdown products of 

 chlorogenic acid plus glycine. These spectra suggest that the 

 quinic acid moiety of chlorogenic acid is not present in the col- 

 ored products. 



