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首页> 外文期刊>Journal of Agricultural and Food Chemistry >Effect of β-Cyclodextrin on the Multistate Species Distribution of 3-Methoxy-4′,7-dihydroxyflavylium. Discrimination of the Two Hemiketal Enantiomers
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Effect of β-Cyclodextrin on the Multistate Species Distribution of 3-Methoxy-4′,7-dihydroxyflavylium. Discrimination of the Two Hemiketal Enantiomers

机译：β-环糊精对3-甲氧基-4'，7-二羟基甲酰巯基的多晶物种分布的影响。 辨别两种半鸟映体

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摘要

The effect of β-cyclodextrin on the mole fraction distribution of the multistate species of the anthocyanin model compound, 3-methoxy-4′,7-dihydroxyflavylium, was studied by NMR, stopped flow, circular dichroism, and UV–visible absorption spectroscopy. The formation of inclusion complexes with hemiketal and trans-chalcone, possessing transition dipole moments in a parallel orientation to the cyclodextrin n-fold axis, was unequivocally proved by means of the positive-induced circular dichroism signal. The discrimination of the two hemiketal enantiomers was achieved by the splitting of 1H NMR peaks in the presence β-cyclodextrin. The spectroscopic data shows that the β-cyclodextrin has only moderate enantioselectivity, slightly favoring one of the optical isomers. The observed binding affinity of β-cyclodextrin for the 3-methoxy-4′,7-dihydroxyflavylium multistate species increases in the order flavylium cation < quinoidal base < hemiketal < trans-chalcone < cis-chalcone. As a result of this selectivity and the dynamic nature of the network, the equilibrium is displaced toward the formation of the chalcone species.]]>
机译：<！[cdata [ src ='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2017/jafcau.2017.65.issue-31/acs.jafc.6b04892/ 2016-04892G_0018.gif“>研究了β-环糊精对花青素模型化合物，3-甲氧基-4'，7-二羟基甲磺基的多晶型物种的摩尔分数分布的影响NMR，停止流动，圆形二色性和UV可见吸收光谱。用半鸟和反式的含有络合物的形成 - 通过阳性透明地证明，具有与环糊精的平行取向的过渡偶极酮酮的转化偶极酮。通过阳性透明地证明了与环糊精ε-lec轴的平行取向。 - 引起的圆形二分态信号。通过在存在β-环糊精中的 1 H NMR峰的分裂来实现两种半鸟对映体的辨别。光谱数据表明，β-环糊精仅具有中等的对映选择性，略微偏好了一种光学异构体。 β-环糊精为3-甲氧基-4'，7-二羟基酚钒多岩物种的观察到的结合亲和力在石油阳离子反式 -Chalcone Cis < / i> -Chalcone。由于这种选择性和网络的动态性质，平衡朝向细菌物种的形成流离失所。]]>

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