Extraction and Isolation. The powder of the whole plants
(5.0 kg) of S. longa was extracted with 95% EtOH at room
temperature ( 3, each for 5 days). After removal of the solvent
under reduced pressure, the residue (280 g) was suspended
in 2.0 L of acidic water (adjusted with 2.0 mol/L H2SO4 to pH
ca. 1-2).