Determination of free ferulic acid and total ferulic acid in Chuanxiongby high-performance liquid chromatography for quality assessment

Abstract

Ferulic acid (FA) is one of the main bioactive compounds in Chuanxiong (CX), the dried rhizome of Ligusticum chuanxiong, but its amount in this herb is difficult to determine accurately. An accurate quantificational method was developed to investigate on the available amount of FA (free FA and total FA). Herbal samples were extracted in methanol-formic acid (95:5) and methanol-0.24 mol x L(-1) sodium hydrogen carbonate in water (95:5), respectively and then quantitatively analyzed by HPLC method. Thirty three CX samples were quantified on free and total FA. Total FA was found more abundant than free FA with an average ratio of 2.38 (n = 32) in the range of 1.03- 4.98 in 32 CX herbs, and a highest ratio of 19.6 was estimated in a rhizome seedling. Results showed that total FA content would be a better marker for the quality assessment of CX herbs. Fifteen CX typical samples were collected from the trueborn cultivating areas in Sichuan province of China. The amount of total FA in these herbs was estimated to be 1.42 mg x g(-1) (n = 15). The proposed limit of total FA in CX samples should not less than 1.25 mg x g(-1) calculated on the dried basis. It was also found that the level of total FA was related to the quality, processing method and store duration of CX samples.