Enrichment and purification of marine polyphenol phlorotannins using macroporous adsorption resins

Phlorotannins are one of the most important bioactive polyphenols; however, their purification using chromatographic methods has not been explored. Here, we studied purification of phlorotannins from the crude phlorotannin extract (CPhE) of the brown seaweed Ecklonia cava using macroporous adsorption resins. For purification of phlorotannins, four resins (HP-20, SP-850, XAD-7HP, and XAD-2) were screened. Among them, HP-20 resin showed the highest adsorption and desorption capacities. In static adsorption tests, the adsorption capacity of HP-20 increased with increasing temperature (25-45°C). Optimal conditions for the dynamic experiments can be summarized as follows: total phlorotannin content (TPhC) in loading solution: 1.5mg PGE/mL, processing volume: 4 BV, flow rate: 1 mL/min, temperature: 45°C, desorption solvent: 40% ethanol solution. After purification, TPhC (452 mg PGE/g) and arsenic (180 μg/g) of CPhE increased and decreased to 905 mg PGE/g and 48 μg/g, respectively. Recovery rate of phlorotannins from CPhE was 92%.