Some thoughts on applications

The recent discovery that Z-retrochalcones (natural anthocyanin retrochalcones) encapsulate iron (III) points out that they can play a nutritional role. Owing to this property, anthocyanins may take part in the uptake and regulation of this vital metal in the human body. If it is the case, it would be wise to consume red fruits (edible berries) with good amounts of structurally simple glycosylated anthocyanins whose Z-chalcones are perfectly sized for complexing iron (III). 

There is a field in chemistry that remains completely open to research and the interactions established between anthocyanins and the large bioorganic and inorganic molecules. Good representatives would be proteins for instance, members of the lectin family and also the human insulin with its 51 amino acids. 

Finally, let us end this section with a few words on the origin of wine color, whether it is red or white. Call it the unifying theory. Everybody knows that red is given by the grape anthocyanins (Brouillard et al, 1997). In our opinion, the pale yellow color of white wines could arise from the presence of iron-chalcone complexes (see Fig. 1.4), and the balance between iron and anthocyanins would determine the final aspect of a white wine. Thus, anthocyanins may be stored in living tissues under almost colorless or yellow combinations. If it is the case, phytochemists looking for new anthocyanin natural structures may turn their attention toward yellow and even white flowering plant species. 

Another very interesting and less explored field is the color changes observed when anthocyanins are in contact with colorless substances, which are not necessarily copigments, for instance, surfactants, emulsions, gels, proteins, DNA, cotton, wool, hair and so on (Bicard, 1999). For hair coloring, anthocyanins could be alternatives to existing synthetic systems and generate new direct dyes for hair (cationic dyes). 

AUinger, N.L. (1977). Conformational analysis. 130. MM2. A hydrocarbon force field utilizing VI and V2 torsional terms. Journal ofthe American Chemical Society, 99, 8127-8134. 

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