CHARACTERIZATION OF ALLAGOCHROME 

 AND ITS BIOSYNTHESIS IN LEAF EXTRACTS 



Helen M. Habermann 



Allagochrotne is a blue-green pigment present in alkaline homo- 

 genates of a wide variety of plant species. Other colored sub- 

 stances (including at least two yellow fractions) are normally pre- 

 sent in crude allagochrome preparations. A survey of the distribu- 

 tion of allagochrome in higher plant groups and a description of 

 techniques which have been developed for the purification and ass^ 

 of allagochrome have been published (2,5) _ There is at least cir- 

 cumstantial evidence that allagochrome is involved in photophos- 

 phorylation and respiration (2,^,6)^ 



The purpose of this paper is to summarize the recent progress to- 

 ward understanding the structure and biosynthesis of allagochrome. 

 Until recently there were few clues about the chemical nature of 

 this pigment and at times the available information was misleading. 



ALLAGOCHROME BIOSYNTHESIS 



For the past several months we have proceeded on the hypothesis 

 that allagochrome is a chlorogenic acid derivative. Briefly, the 

 evidence for involvement of chlorogenic acid in allagochrome syn- 

 thesis is as follows: 



1) It is well known that a green derivative forms spontaneously 

 from chlorogenic acid in the presence of ammonia. The ammonia de- 

 rivative is spectrophotometrically different from allagochrome. 

 Another chlorogenic acid derivative which forms slowly in the pres- 

 ence of glycine in alkaline medium resembles allagochrome more 

 closely. The latter derivative is reduced to a yellow form by hy- 

 drosulfite, is autoxidizable and turns red in acid. In other 

 words it has properties which are descriptively the same as those 

 of allagochrome. 



2) The addition of chlorogenic acid during the grinding of plant 

 materials testing positively for allagochrome increases yields up 

 to several fold. Absorption spectra of such enhanced crude prep- 

 arations match those of control preparations rather well except 

 for slight shifts of peak position in the red and major increases 

 in absorbancy in the blue with a shift to shorter wavelengths for 



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