Components of protocyanin, a blue pigment from the blue flowers of Centaurea cyanus.
The components involved in the formation of protocyanin, a stable blue complex pigment from the blue cornflower, Centaurea cyanus, were investigated. Reconstruction experiments using highly purified anthocyanin [centaurocyanin, cyanidin 3-O-(6-O-succinylglucoside)-5-O-glucoside], flavone glycoside [apigenin 7-O-glucuronide-4'-O-(6-O-malonylglucoside)] and metals, Fe and Mg, showed the presence of another factor essential for the formation of protocyanin. The unknown factor was revealed to be Ca. Reconstructed protocyanin using anthocyanin, flavone, Fe, Mg, and Ca was identical with protocyanin from nature in UV-Vis and CD spectra, and was isolated as crystals for the first time. In addition, substitution of the metal components in protocyanin with other metals was also examined.
Takeda
Kosaku
K
Department of Biology, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan. takedks@ss.iij4u.or.jp
Osakabe
Akiko
A
Saito
Shinomi
S
Furuyama
Daisuke
D
Tomita
Atsuko
A
Kojima
Yumi
Y
Yamadera
Mayumi
M
Sakuta
Masaaki
M
D000872:Anthocyanins / Q000737:chemistry* / Q000302:isolation & purification; D031179:Centaurea / Q000737:chemistry*; D018360:Crystallography, X-Ray; D035264:Flowers / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification; D008670:Metals / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010860:Pigments, Biological / Q000737:chemistry* / Q000302:isolation & purification; D013053:Spectrophotometry
D000872:Anthocyanins; D006027:Glycosides; D008670:Metals; D010860:Pigments, Biological; C504639:protocyanin