Phytochemistry: Structure of the blue cornflower pigment

  title={Phytochemistry: Structure of the blue cornflower pigment},
  author={Masaaki Shiono and Naohiro Matsugaki and Kǒsaku Takeda},
The same anthocyanin pigment makes roses red but cornflowers blue, a phenomenon that has so far not been entirely explained. Here we describe the X-ray crystal structure of the cornflower pigment, which reveals that its blue colour arises from a complex of six molecules each of anthocyanin and flavone, with one ferric iron, one magnesium and two calcium ions. We believe that this tetrametal complex may represent a previously undiscovered type of supermolecular pigment. 

Blue metal complex pigments involved in blue flower color

  • K. Takeda
  • Chemistry, Medicine
    Proceedings of the Japan Academy. Series B, Physical and biological sciences
  • 2006
The author focuses on the investigations of the blue metal complex pigments involved in the bluing of flowers, commelinin from Commelina commusis, protocyanin from Centaurea cyanus, protodelphin from Salvia patens and hydrangea blue pigment.

Structure of commelinin, a blue complex pigment from the blue flowers of Commelina communis.

The results demonstrate that commelinin is a tetranuclear (4 Mg(2+)) metal complex, in which two Mg (2+) ions chelate to six anthocyanin molecules, while the other two MG(2+) ion bind to six flavone molecules, stabilizing the commelinIn complex, a new type of supramolecular complex.

Blue flower color development by anthocyanins: from chemical structure to cell physiology.

This review focuses on the advances in the last 15 years, and cites 149 references, in understanding blue flower coloration since the comprehensive review by Goto and Kondo in 1991.

Metal Complex Pigment Involved in the Blue Sepal Color Development of Hydrangea.

The mixing conditions to reconstruct the same blue color as observed in the sepals were studied and indicated that in the hydrangea-blue complex 1 might be under equilibrium between chelating and nonchelating structures having an interaction with 2.

Chemistry and photochemistry of natural plant pigments: the anthocyanins

Anthocyanins are naturally occurring plant pigments responsible for the red, blue, and purple colors of the majority of fruits, flowers, and leaves. The pH-dependent ground-state chemistry of

Stabilizing and Modulating Color by Copigmentation: Insights from Theory and Experiment.

This review revisits this phenomenon to provide a comprehensive description of the nature of binding and of spectral modifications occurring in copigmentation complexes, in which charge transfer plays an important role.

Biosynthesis of plant pigments: anthocyanins, betalains and carotenoids.

Three classes of pigments act as visible signals to attract insects, birds and animals for pollination and seed dispersal, and protect plants from damage caused by UV and visible light.



Structural basis of blue-colour development in flower petals from Commelina communis

The blue flower-colour development and the stability of the colour can be explained by metal complexation of antho-cyanin and intermolecular hydrophobic association.

The Flavonoids Advances in Research Since 1986

The anthocyanins. Flavans and proanthocyanidins. C-Glycosyl flavonoids. Biflavonoids and triflavonoids. Isoflavonoids. Neoflavonoids. Flavones and flavanols. Flavone and flavonol glycosides. The

Komplexbildung und Blütenfarben

Der Farbstoff der blauen Kornblume, Protocyanin, ist ein Komplex von hohem Molekulargewicht. Eisen(III)- und Aluminium-Ionen bilden mit der Anhydrobase des Cyanins tiefblaue Chelate, die im