Abstract

Cinnamic acid and harpagoside are important active components present in Scrophularia ningpoensis, which has been used in the treatment of several diseases such as pharyngalgia. In the present study, a novel method based on high performance liquid chromatography (HPLC) following microwave-assisted extraction (MAE) was developed for the determination of cinnamic acid and harpagoside in a traditional Chinese medicine (TCM) of S. ningpoensis. Effective chromatographic separation was achieved on a C18 column at the detection wavelength of 278 nm. Microwave power of 400 W and irradiation time of 4 min were found to be the optimum conditions for the MAE process. In addition, to demonstrate the feasibility of the MAE-HPLC method, the conventional ultrasound extraction (USE) method was used for the analysis of cinnamic acid and harpagoside in the TCM. The results indicated that MAE-HPLC is a simple, rapid, efficient, and low cost method for the determination of cinnamic acid and harpagoside in TCM as well as a potential tool for the assessment of TCM quality.

Key words: Scrophularia ningpoensis, Cinnamic acid, harpagoside, microwave-assisted extraction, liquid chromatography, traditional Chinese medicine.