1993 Fiscal Year Final Research Report Summary
Studies on Structural Analysis of Molecular Association of Flower Pigments, Anthocyanins
| Project/Area Number |
04640525
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
天然物有機化学
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| Research Institution | Nagoya University |
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Principal Investigator |
KONDO Tadao Nagoya University, Associate Professor Chemical Instrument Center, 化学測定機器センター, 助教授 (70093028)
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| Project Period (FY) |
1992 – 1993
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| Keywords | anthocyanin / molecular association / strucutral analysis / color variation / stability / commelinin / protocyanin / X-ray crystallography |
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| Research Abstract |
Commelinin is a real pigment of blue petals of Commelina communis and a metal-complex involving self-association and copigmentation. We obtained it as a pure pigment by reconstruction from the components, malonylawobanin (M), flavocommelin (F) and magnesium ion. By reconstruction experiments of the commelinin-like pigments by replacement of the components the metal-coordination position was determined. The exact structural analysis was succeeded by ^1H NMR,CD and atomic analyzes followed by X-ray crystallographic analysis using synchrotoron radiation. M and M,and F and F are stacking each other in face-to-face in left-handed screw and M and F is in right-handed manner. The gross strucutre is cyclo-MMFFMMFFMMFF.The association is due to hydrophobic interaction of the aromatic nuclei. The blue color development is due to the 4'-keto anhydrobase anion of the anthocyanidin nucleus arising from metal chelation.
Protocyanin is a real pigment from blue corn flower, Centaurea cyanus. We first detrmined the exact molecular weight by ESI-mass, and established the composition by reconstruction from components, succinylcyanin (Sc), malonylflavone (Mf), Fe^<3+> and Mg^<2+> tobe [Sc_6Mf_6Fe^<3+>Mg^<2+>].
We first succeeded in exact structural elucidation of real flower pigment and put a period of controversy of metal-complex theory during 70 years.
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