Flash-column chromatography was carried out by using normal-phase silica gel (33 70 μm) supplied by VWR.
DHM was purified from this kava product using normal phase silica gel chromatography as described earlier.
Waxes were precipitated first and the extract was separated into five fractions using normal-phase HPLC with a silica column.
Flash chromatography was carried out by using 60 230 mesh silica gel (Kanto Chemical, silica gel 60N).
BL and CS were extracted with methanol and purified by solvent partitions by using a silica gel column and ODS-HPLC as follows.
Thin-layer chromatography (TLC) was performed by using Merck silica gel 60 F254 precoated plates (0.25 mm).
Separation by column chromatography was carried out by using silica gel (Merck 7749, 7734, and 9385), while silica gel 60 PF254 aluminium sheets were used for TLC analysis.
To verify the pretreatment method, we compared the 3H concentration obtained by using silica gel with that obtained by lyophilization of four plant samples.
Chromatography was conducted by using 200 300 mesh silica gel.
Column chromatography purification was carried out by using silica gel.
