Isolation and Formulation of Dieckol from Ecklonia cava

Dieckol was a light brown powder and was provided by Botamedi, Inc. (Jeju, Korea); its specifications are available elsewhere [25 (link)]. Briefly, the whole E. cava plant was collected off the coast of Jeju Island, South Korea. Dried E. cava powder was extracted with 70% aqueous ethanol and partitioned between water and ethyl acetate. The ethyl acetate fraction was subjected to octadecylsilyl (ODS) column chromatography followed by gel filtration in a Sephadex LH-20 column equilibrated with methanol. Final purification was accomplished by HPLC (Waters Spherisorb S10 ODS2 column (20 × 250 mm); eluent, 30% methanol; flow rate, 3.5 mL/min) to isolate dieckol (98.5 wt%). As the vehicle, 2 wt%, 5000–10,000 kDa high-molecular-weight HA was used (MNH Bio, Hwaseong, Korea). The dieckol+vehicle was prepared as follows: 0.2 g of dieckol was mixed with 3 mL of 10% ethanol and 0.9 mL of normal saline at 37 °C and centrifuged for 30 min. Next, 16.1 mL of high-molecular-weight HA were stirred into the solution for 24 h.