Abstract：
The complexation of herbal constituents with cyclodextrin has been a useful tool to improve their aqueous solubility. However, the simultaneous complexation of these compounds still lacks detailed studies. The present study investigated the multicomplexation of quercetin (QCT), luteolin (LUT), and 3-O-methylquercetin (3OMQ) with (2-hydroxypropyl)-β-cyclodextrin (HPβCD), when they are simultaneously contained in a flavonoid-enriched fraction (FEF) of Achyrocline satureioides. The phase-solubility diagram revealed a linear correlation between the flavonoids solubility and the HPβCD concentration, demonstrating the formation of complexes with a 1:1 stoichiometric ratio, which was confirmed by ESI-MS. Negative ΔG0 values indicated that complexation was spontaneous. Flavonoids/HPβCD interactions were evidenced by FT-IR, DSC, SEM, and 1D and 2D NMR. The last one showed the formation of inclusion complexes by insertion of the B-ring of the flavonoids into the cavity of HPβCD. Unexpectedly, the FEF/HPβCD complex showed a radical scavenger potential lower than the FEF. The HPLC analysis revealed that the complex contained different flavonoid ratio than the fraction. Thus, the antioxidant capacity of the samples was demonstrated to be related to the ratio among the flavonoids, rather than to the total flavonoids. These new findings are very useful for developing herbal cyclodextrin-based products from A. satureioides or other herbal products.
摘要：
草药成分与环糊精的络合一直是改善其水溶性的有用工具。然而,这些化合物的同时络合仍然缺乏详细的研究。本研究调查了槲皮素（QCT）的多重络合，木犀草素（LUT），和3-O-甲基槲皮素（3OMQ）与（2-羟丙基）-β-环糊精（HPβCD），当它们同时包含在Achyroclinesatureioides的富含类黄酮的部分（FEF）中时。相溶解度图揭示了类黄酮溶解度与HPβCD浓度之间的线性相关关系，证明了化学计量比为1:1的络合物的形成，ESI-MS证实了这一点。负的ΔG0值表明络合是自发的。黄酮/HPβCD相互作用由FT-IR证明，DSC,SEM,以及1D和2DNMR。最后一个显示通过将类黄酮的B环插入HPβCD的腔中而形成包合物。出乎意料的是,FEF/HPβCD复合物显示出低于FEF的自由基清除剂潜力。HPLC分析显示该复合物含有与该部分不同的类黄酮比例。因此，样品的抗氧化能力被证明与类黄酮之间的比例有关，而不是总黄酮。这些新发现对于开发基于草药环糊精的产品非常有用。satureioides或其他草药产品。
