Determination of (E)-ferulic acid content in the root of Angelica acutiloba: a simple chemical evaluation method for crude drug quality control

The root of Angelica acutiloba Kitagawa is an important crude drug in Kampo medicines (traditional Japanese medicine). Chemical evaluation of crude drugs is crucial to ensuring the safety and efficacy of herbal medicine; however, there is currently no chemical standard for the A. acutiloba crude drug in Japanese pharmacopoeia. (E)-ferulic acid (FA) is an important active ingredient of Angelica spp., including A. sinensis (Oliv.) Diels, and has been suggested as a marker for quality evaluation of those crude drugs. However, it has been controversial whether FA is a reliable marker constituent of A. acutiloba. To achieve effective extraction of FA from A. acutiloba, we compared three different extraction methods: alkaline hydrolysis, ethanol extraction, and hexane extraction. FA levels in these extracts were assessed using high performance liquid chromatography (HPLC), and alkaline hydrolysis was found to be the most effective. Furthermore, in the hydrolysate, FA was distinctly identified by thin layer chromatography (TLC) analysis. These results provide useful information for the quality control of the A. acutiloba crude drug.