作者:M. Elhabiri、P. Figueiredo、K. Toki、N, Saito、R. Brouillard
DOI:10.1039/a603851d
日期:——
Complexation of aluminium and gallium ions with synthetic
anthocyanin models and natural anthocyanins extracted from the blue flowers
of Evolvulus pilosus cv âBlue Dazeâ and the violet
flowers of Matthiola incana has been thoroughly investigated in
aqueous solution. From UVâVIS spectroscopic data collected at pH
2â5, the presence of complexes, involving not only the coloured forms
but also the colourless forms of the pigments is demonstrated. A
theoretical treatment is developed for the calculation of the corresponding
stability constants. The pigments studied throughout this work can be
divided into two series, one sharing a cyanidin chromophore and the other a
delphinidin one. Within both series, individual pigments are distinguished
according to the degree and type of glycosylation and/or acylation.
Intramolecular effects such as copigmentation of
anthocyaninâaluminium complexes and the effect of the presence of a
malonyl group on the formation of those complexes are discussed. These
results are important to plant pigmentation and, for instance, a narrow pH
domain in which colour amplification due to complexation is at a maximum
has been found.
我们深入研究了铝和镓离子在水溶液中与合成花青素模型以及从蓝花楹(Evolvulus pilosus cv âBlue Daze)和紫花地丁(Matthiola incana)中提取的天然花青素的络合情况。根据在 pH 值为 2â5 时采集的紫外可见光谱数据,证明了存在络合物,其中不仅包括有色形式的颜料,还包括无色形式的颜料。为计算相应的稳定性常数,还开发了一种理论处理方法。本研究中研究的颜料可分为两个系列,一个系列中的颜料具有青花苷发色团,另一个系列中的颜料具有翠绿苷发色团。在这两个系列中,根据糖基化和/或酰化的程度和类型来区分不同的色素,并讨论了分子内效应,如花青素铝络合物的共着色以及丙二酰基团的存在对形成这些络合物的影响。这些结果对植物色素沉着非常重要,例如,研究人员发现了一个狭窄的 pH 值域,在该值域中,络合作用导致的颜色放大达到最大值。