Distribution Patterns of Allagochrome, Chlorogenic Acid, and Capacity for Secondary Synthesis of Allagochrome

Abstract

Allagochrome is a blue-green, water-soluble pigment found in alkaline extracts of many plant species. Unique properties of allagochrome are its color changes in response to oxidation and reduction (blue-green to yellow) and to changes in pH (blue-green to red). Some plant materials exhibit the phenomenon of secondary synthesis (i.e., increased yields of allagochrome when chlorogenic acid is added during extraction). To determine whether allagochrome (A), chlorogenic acid (C), and capacity for secondary synthesis (S) always occur together or can be found independently, over 200 plant species were assayed for these factors. Because each factor can be either positive or negative, there are in all eight possible descriptive categories with respect to these components The assay data show that every category is represented among the species tested. The two most numerous categories are A+ C+ S+ and A- C- S-. Mutants can differ from their wild types with respect to these factors. Wild-type Helianthus annuus leaves are A+ C+ S+, while xantha mutant leaves are A- C+ S+ and albina leaves are A- C- S-. Also, other parts of a plant can differ from leaves in their assay values; wild-type sunflower stems and roots are A- C- S+. Because these factors are descriptive characteristics for both species and larger plant taxa, they are potentially useful for studies of chemical taxonomy.