Inclusion Of Three ¦Â-cyclodextrin Derivatives With Mangosteen Flavonoids, Kaempferol And Galangal Factors

Mangostin,kaempferol and galangin have been paid widespread concern in recent years for their extensively pharmacological effects.But they are all poorly water-soluble and low oral bioavailability,which limited their use in the pharmaceutical fled and their clinical application.β-cyclodextrin(β-CD) derivatives are highly efficient,low toxic,safe and effective.So,studying on the complexing behavior and the solubility effect ofβ-CD derivatives with mangostin,kaempferol and galangin is very important to their use in the pharmaceutical fled and their clinical application.The main contents and conclusions are as following:At first,the complexing behavior and the solubility effect of severalβ-CD derivatives withα-mangostin(α-MAG) have been studied comparatively by phase solubility method.The inclusion complex of hydroxypropyl-β-cyclodextrin(Hp-β-CD) withα-MAG was prepared and characterized by infrared absorption spectroscopy(IR),differential scanning calorimetric analysis(DSC) and ~1H nuclear magnetic resonance spectroscopy (~1HNMR).The effect of temperature on the reaction process has been investigated.The results indicate that the threeβ-CD derivatives can react withα-MAG forming 1:1 host-guest stable complexes.The inclusion ability ofβ-CD derivatives was consistent with the solubility enhancements of threeβ-CD derivatives toα-MAG and followed the order:sulfobutyl ether-β-cyclodextrin(SBE-β-CD)＞Hp-β-CD＞hydroxyethyl-β-cyclodextrin(HE-β-CD).The temperature has little effect on the process of inclusion of Hp-β-CD withα-MAG.The whole inclusion process is controlled mainly by enthalpy and is driven by van der waals'forces. Secondly,the fluorescence spectroscopy and phase solubility method were used to study on the inclusive behavior and the solubilizing effect of threeβ-CD derivatives withγ-mangostin (γ-MAG).The influence of temperature and pH value on the reaction of Hp-β-CD withγ-MAG was investigated respectively.The inclusion complex of Hp-β-CD withγ-MAG was prepared and characterized by IR and DSC.As can been shown that threeβ-CD derivatives had a strong ability to quench the fluorescence ofγ-MAG.SBE-β-CD and HE-β-CD can react withγ-MAG forming 1:1 host-guest complexes but Hp-β-CD andγ-MAG forming a 2:1 inclusion complex respectively under neutral conditions.The solubilization capacity ofβ-CD derivatives was the order:SBE-β-CD＞Hp-β-CD＞HE-β-CD.Hp-β-CD can react withγ-MAG forming a 1:1 host-guest complexe under the pH of 1.2,but no inclusive phenomenon was observed at the pH of 7.5.There is no evident difference of the apparent stability constant of inclusion complex at different temperatures.And furthermore the interactions between kaempferol and threeβ-CD derivatives have been studied comparatively by phase solubility method.The results showed that threeβ-CD derivatives all can react with kaempferol forming 1:1 host-guest complexes and the solubilization is obvious.The order of the inclusion and solubilization capacity is:SBE-β-CD＞HE-β-CD＞Hp-β-CD.Finally the inclusion complexes of threeβ-CD derivatives with galangin were studied by fluorescence spectroscopy.The effect of the temperature on the apparent stability constant of inclusion complex was investigated. The results showed that threeβ-CD derivatives all had a strong ability to quench the fluorescence of galangin.The threeβ-CD derivatives all can react with galangin forming 1:1 host-guest complexes.The order of the inclusion capacity is SBE-β-CD＞Hp-β-CD＞HE-β-CD. Temperature has little effect on the process of inclusion reaction which is a spontaneous exothermic process.