Aqueous Solubility and Stability Enhancement of Astilbin through Complexation with Cyclodextrins

作者：Zhang, Qing-Feng^*; Nie, Hai-Chun; Shangguang, Xin-Cheng; Yin, Zhong-Ping; Zheng, Guo-Dong; Chen, Ji-Guang

来源：Journal of Agricultural and Food Chemistry, 2013, 61(1): 151-156.

DOI：10.1021/jf304398v

• astilbin
• cyclodextrin
• complexation
• solubility
• stability

The complexation of astilbin with alpha-, beta-, and gamma-cyclodextrin (CD) was studied by phase solubility test and UV-vis spectral titration. Complexation with CDs gradually decreased the absorbance of astilbin at 291 nm and obviously increased its water solubility. The formation constant (K-a) between astilbin and the three CDs was calculated. The stability of astilbin complexes increased in the order alpha-CD < gamma-CD < beta-CD, attributed to the CDs' cavity size. Temperature studies showed that the K-a value decreased along with the rise of temperature. The negative values of enthalpy and entropy during complexation indicated that the complexation process was enthalpy-controlled. In alkaline medium isomerization and decomposition of astilbin were found; however, the addition of CDs significantly improved its stability through complexation. The solubility of astilbin in beta-CD microcapsules prepared by the freeze-drying method was enhanced by 122.1-fold, and its dissolution profile was improved.

• 出版日期2013-1-9
• 单位江西农业大学