Fig. 1

a HPLC and b ABTS⁺ online HPLC chromatogram of IOEA. Column: Atlantis T3 3 μm ODS column (150 mm × 4.6 mm i.d.); mobile phase: acetonitrile-water (0 → 40 min, 5:95 → 50:50 v/v; ~50 min, ~100:0 v/v; ~70 min, ~100:0 v/v); a flow rate of 200 μL/min, monitored at 230 nm. ABTS⁺ solution excreted at a flow rate of 700 μL/min and was measured at 680 nm absorbance. Peak I: DPHC, peak II: OPA