The ninth fraction from Sephadex LH-20 chromatography was fractionated on an ODS column, eluted with a stepwise gradient (0–100% MeOH/H2O) to afford 11 fractions; the third fraction was subjected to HPLC fractionation (Zorbax SB-C18, 5 μm, 250 × 9.4 mm column, 3.0 mL/min, gradient elution from 30 to 80% MeCN/H2O over 20 min, with isocratic 0.01% TFA modifier) to yield 7a/b.