Standardization and Verification of Ecklonia cava Extract

A 50% ethanol extract of IO was provided by Shinwoo Co. Ltd. (Lot No. SW9E29SA, Gyeonggi-do, Korea). Briefly, the IO used in this study was standardized on the assumption of diphlorethohydroxycarmalol (DPHC, 2.37%) by an HPLC analysis method [4 (link)] with a slight modification. IPA was purified on a pure C-850 FlashPrep chromatography system equipped with a PDA detector or an ELSD detector (all from Buchi, Flawil, Switzerland), equipped with an YMC Pack ODS-A (20 mm × 250 mm, 5 µm). The mobile phase consisted of (A) 0.1% formic acid in water and (B) ACN containing 0.1% formic acid. The HPLC elution was conducted as follows: 20%–40% B for 25 min, followed by a 10 min re-equilibration period of the column. The flow rate was maintained at 9 mL/min and the injection volume was 2 mL. IPA was verified by using quadrupole time-of-flight liquid chromatography-mass spectrometry (Q-TOF LC-MS/MS) using an electrospray ionization (ESI) source (maXis-HD, Bruker Daltonics, Breman, Germany) at the Korea Basic Science Institute (KBSI; Ochang, South Korea), targeted at the m/z 1986.26 fragment.