β-胡萝卜素与β-CD包结物的制备及其稳定性

Preparation of inclusion compound of β-carotene with β-cyclodextrin and stubility

用紫外 -可见光谱法研究了 β 胡萝卜素与 β 环糊精的生成和包结常数。结果表明 ,1分子 β 胡萝卜素与 3.2 5分子β 环糊精分子依据范德华作用力和疏水作用力发生包结作用 ,生成稳定的包结物。包结物适宜的制备条件为 :β 环糊精与 β 胡萝卜素的摩尔比为 3.2 5∶1 ,主客体溶液的浓度比为1 2∶1 ;包结温度 30℃ ;反应时间 2h。包结物的生成常数为9.4 6× 1 0 1 1 L/mol,包结物稳定。包结物中的 β 胡萝卜素在光氧存在条件下不易降解 。

carotene with β CD was prepared, equilibrium constant of inclusion compound was determined by UV vis spectra. The results indicated that one mole β carotene could be included by 3.25 moles β CD to form inclusion compound by Van Der Waals force and hydrophobic interaction. That optimum synthesis condition of inclusion compound of β CD with β carotene was: the mole ratio of β CD/β carotene 3.25∶1(mol/mol) and concentration ratio of β CD H 2O solution/β Carotene solution 12∶1(mol·L -1 /mol·L -1 ), the time and temperature of included reaction 2 h and 30 ℃. Equilibrium constant of inclusion compound(Ka) was 9.46×10 11 L/mol. The selective binding ability of β CD with β carotene was discussed from the viewpoint of size/shape fitting and geometry fitting between the host cavity and the guest molecular. The resistance of β carotene to oxidation and photooxidation were increased by inclusion with β CD.