The organic fraction (23 g) was collected and then dissolved in
MeOH, and the resulting solution was subjected to column chromatography
over silica gel eluting with CHCl3/MeOH (from 1:0–0:1) to afford five
fractions (Fr. A–D). Fr. A (7.2 g) was subjected to RP-18 column chromatography
(MeOH/H2O 35:1, 50:1, 70:1, 90:1, 0:1) and silica gel column
chromatography (CHCl3/MeOH 95:5–10:1) to yield compounds 4