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.