Study on triterpenic acids purification from jujube by macroporous resins and its antioxidant activity

The purification characteristics by macroporous resin and antioxidant activity of triterpenic acids from jujube was evaluated in this study. D101 was optimized from 3 types of macroporous resins ( D101, AB-8, X-5) for triterpenic acids purification by static adsorption-desorption experiments, and the related adsorption isotherm, adsorption kinetics and the optimal purification conditions was also investigated. The results showed that D101 macroporous resin presented good capabilities of adsorption and desorption of triterpenic acids from jujube, and the kinetics fitted the pseudo-second-order rate equation and its equilibrium adsorption data for triterpenic acids was accordance with Freundlich adsorption isothermal equation.Furthermore, the adsorption capacity was increased with higher temperature.The optimal purification condition was as follows: 7 BV of sample solution ( p H7) and then 5 BV of ethanol solution ( 95%, p H11) as eluent. Under this condition, the purity of triterpenic acids was increased from 49% to 78%. Moreover, the ability of triterpenic acids from jujube to scavenge ABTS+·and·OH was increased, while the ability to scavenge DPPH·was decreased after purification.