Determination of Tanshinones in Danshen (Salvia miltiorrhiza) by High-Performance Liquid Chromatography with Fluorescence Detection after pre-Column Derivatisation.

INTRODUCTION: Tanshinones are a major class of bioactive ingredients in the traditional herbal medicines, Danshen (Salvia miltiorrhiza). A sensitive and reliable determination method for tanshinones is useful to ensure the quality of Danshen. OBJECTIVE: To develop a sensitive and selective analytical method for tanshinones by high-performance liquid chromatography (HPLC) with fluorescence detection after pre-column derivatisation. METHODOLOGY: The proposed method depends on derivatisation reaction of tanshinones with 4-carbomethoxybenzaldehyde and ammonium acetate forming intensely fluorescent imidazole derivative. RESULTS: The proposed method provided excellent sensitivity with the detection limits of 3.3 nM (66 fmol/injection), 3.2 nM (64 fmol/injection) and 2.0 nM (40 fmol/injection) for cryptotanshinone, tanshinone I and tanshinone IIA, respectively, without the necessity of complicated instrumentations. The developed method is successfully applied to quantify the contents of tanshinones in Danshen. CONCLUSION: The developed method is the first analytical method for tanshinones by fluorescence detection. Since the derivatisation reaction is selective for the o-quinone structure of tanshinone, the developed method will become a suitable mean for the discovering of tanshinone type diterpenoids from herbal samples. Copyright © 2017 John Wiley & Sons, Ltd.