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首页> 外文期刊>Helvetica chimica acta >gamma-cyclodextrin as inhibitor of the precipitation reaction between berberine and glycyrrhizin in decoctions of natural medicines: Interaction studies of cyclodextrins with glycyrrhizin and glycyrrhetic acid by H-1-NMR spectroscopy and molecular-Dynamics Calculation
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gamma-cyclodextrin as inhibitor of the precipitation reaction between berberine and glycyrrhizin in decoctions of natural medicines: Interaction studies of cyclodextrins with glycyrrhizin and glycyrrhetic acid by H-1-NMR spectroscopy and molecular-Dynamics Calculation

机译：γ-环糊精作为黄连素与甘草甜素在天然药物汤中沉淀反应的抑制剂：环糊精与甘草甜素和甘草次酸的相互作用的H-1-NMR光谱和分子动力学计算

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摘要

To prevent the precipitation reaction between glycyrrhizin (1) and berberine (3) in the decoctions of Glycyrrhiza/Coptis rhizome or Glyqyrrhiza/Phellodendron bark, the presence of cyclodextrin (CD) in the mixture was proven to be effective. The preventing effect decreased in the order gamma-CD > beta-CD, and no effect was observed for alpha-CD. On the other hand, the extraction degree of 1 from the natural medicine Glycyrrhia was considerably increased in the presence of gamma-CD, gamma-CD being much more effective than alpha- or beta-CD. Thus, the blocking effect of CD on the precipitate formation between I and 3 is suggested to be primarily dependent on the stability of the inclusion complex of the CD with 1. To establish the structure of such a preferred inclusion complex, the interactions of 1 with beta- and gamma-CDs were investigated by H-1-NMR spectroscopy and molecutar-dynamics (MD) calculations. The H-1-NMR measurements showed that the increase in solubility of 1 in H2O is dependent on the degree of its inclusion into the CD, which depends on the molecular size of the CD. The MD calculations suggested that the H-bond interactions are sufficiently strong to form a stable [1/gamma-CD] complex, in which the lipophilic rings C, D, and E of 1 are fully inserted into the molecular cavity of gamma-CD, thus forming a kind of structure covered by a hydrophilic molecular capsule, while such an interaction mode is impossible for alpha- or beta-CD.
机译：为防止甘草/黄连或甘草/黄柏树皮汤中甘草甜素（1）和小ber碱（3）之间发生沉淀反应，混合物中存在环糊精（CD）是有效的。预防效果按γ-CD>β-CD的顺序降低，而对α-CD没有观察到效果。另一方面，在存在γ-CD的情况下，天然药物甘草的提取度为1，大大提高了，γ-CD比α-或β-CD更有效。因此，建议CD对I和3之间的沉淀形成的阻断作用主要取决于CD与1的包合物的稳定性。为了建立这种优选的包合物的结构，1与CD的相互作用。通过H-1-NMR光谱和分子动力学（MD）计算研究了β-和γ-CD。 H-1-NMR测量表明1在H2O中的溶解度增加取决于其在CD中的包被程度，这取决于CD的分子大小。 MD计算表明，H键相互作用足够强以形成稳定的[1 /γ-CD]复合物，其中1的亲脂环C，D和E完全插入γ-CD的分子腔中从而形成一种被亲水性分子胶囊覆盖的结构，而这种相互作用模式对于α-或β-CD是不可能的。

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