Adsorption/Desorption on Macroporous Resins of Okicamelliaside in the Extract of Camellia nitidissima Chi Leaves

Okicamelliaside (OCS) from Camellia nitidissima Chi (C. nitidissima) leaves can be used in therapeutic drugs or nutritional foods. However, which resin is the best for separating OCS and the underlying mechanism for its superiority remains unclear. In this study, the differences in the adsorption/desorption effectiveness and adsorption kinetics of OCS on five resins were compared. AB-8 was found to be an effective resin for the separation of OCS and the adsorption kinetics followed a pseudo-first order model (R-2 > 0.99). In order to optimize the separation of OCS by the resin AB-8, the adsorption time, OCS sample concentration, eluent solvent and volume were tested using a 7 mL column with a diameter of 2 cm. The results showed that the optimum adsorption time was 30 min and the optimum sample concentration was 2.5 mg/mL, while the optimum desorption was achieved by using 2.1 times column volume of 60% ethanol solution. The separation yielded a purified extract with OCS of 290.82 (+/- 2.17) mg/g, which was 6.0 times more than the crude extract (E1, 48.51 (+/- 0.56) mg/g of OCS). This study highlights the use of AB-8 resin for the separation of OCS as an effective technique on the basis of the adsorption/desorption of OCS on the resin. The method has the potential for obtaining green OCS extract with a high OCS content from the crude extract of the leaves of C. nitidissima.