Extraction and Isolation. The air-dried whole plants of C. henryi
(4.0 kg) were extracted with MeOH (3 × 40 L) under reflux. The
solvent was evaporated to obtain a residue (0.4 kg), which was
subsequently suspended in H2O (1.5 L) and partitioned with EtOAc
(3 × 1.5 L). The resulting EtOAc-soluble part (306 g) was
chromatographed on a silica gel column, using mixtures of petroleum
ether/acetone of increasing polarity (100:0 to 100:30, 18 L for each
gradient elution), to afford nine fractions (F1−F9) on the basis of TLC
analyses. F4 (10 g) was fractionated by MPLC over ODS (MeOH in
H2O, 72−90%) to give five subfractions (F4‑1−F4‑5). F4‑4 was purified
by HPLC (85% MeOH in H2O) to yield compounds 8 (tR = 36 min,