环糊精聚合物吸附分离姜黄素类化合物

Adsorptive Separation of Curcuminoids by Cyclodextrin Polymers

摘要:

以环糊精聚合物为吸附剂，吸附分离姜黄提取物中姜黄素类化合物，包括姜黄素 (CUR)、去甲氧基姜黄素 (DMC)、双去甲氧基姜黄素 (BDMC)。首先，通过荧光光谱法分别测得CUR、DMC、BDMC与β-环糊精 (β-CD)的包结常数Kf分别为28.04、73.03、110.83 L/mol，说明环糊精与三者的作用力大小顺序为BDMC > DMC > CUR。然后，制备了6种环糊精聚合物，以分离效果最佳的HP-β-CDP1作为吸附剂进行单组分动力学研究和等温竞争吸附实验，可知60 min到达吸附平衡，吸附动力学符合准二级动力学模型，吸附等温线符合Freundlich等温吸附模型。DMC相对于CUR的分离因子α21约为2 ~ 3，BDMC相对于DMC的分离因子α32 约为2.4 ~ 4.1，BDMC相对于CUR的分离因子α31约为5 ~ 11，吸附后溶液中CUR、DMC、BDMC的色谱含量分别为88.2 %、10 %、0.4 %。结果表明，环糊精聚合物可以选择性吸附分离CUR、DMC和BDMC。

Abstract:

In this paper，curcuminoids from the rhizomes of turmeric, including curcumin (CUR), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC), were isolated by selective adsorption using cyclodextrin polymers as adsorbents. Firstly, the apparent formation constants (Kf) for β-CD with three curcuminoids were measured by fluorescence spectroscopy, the values were 28.04, 73.03, and 110.83 L/mol, indicating that the strength of the interactions between β-CD and curcuminoids is BDMC > DMC > CUR. Then, six kinds of cyclodextrin polymers were prepared and HP-β-CDP1 is the best adsorbent for the separation. The adsorption kinetics and isothermal adsorption experiments were carried out by HP-β-CDP1. It was obtained that the adsorption reached equilibrium within about 60 min and the adsorption behavior could well be depicted by Freundlich equations and pseudo-second-order kinetic model．In addition, The separation factors (α) of DMC and CUR (α21), BDMC and DMC (α32), BDMC and CUR (α31), were about 2 ~ 3, 2.4 ~ 4.1, and 5 ~ 11, respectively. Affter the absorption, the content of CUR, DMC, and BDMC were 88.2%, 10%, and 0.4%, respectively. The results show that CUR, DMC, and BDMC can be selectively separated from commercially available curcumin (CACur) with cyclodextrin polymers.