Convenient TLC-based Identification Test for the Crude Drug "Pogostemoni Herba"

TLC and HPLC were used to identify possible chemical markers for evaluating the quality of the crude drug "Pogostemoni herba" (aerial part of Pogostemon cablin), which is a component of Kampo medicines. In addition to the reported patchouli alcohol and 2-hydroxy-6-methyl-3-(4-methylpentanoyl)-4-pyrone, three phenylethanoids were isolated from this plant material for the first time: acteoside, isoacteoside, and crenatoside. The usefulness of these compounds as indicators of the crude commercial drug under various TLC conditions was examined, and patchouli alcohol was found to give a definite spot with a reproducible Rf value. Therefore, we propose TLC of the methanol (MeOH) extract using patchouli alcohol as a marker as a convenient method for identifying the crude drug Pogostemoni herba.