Comparison of Extraction Efficiency of Tanshinones from S. miltiorrhiza by Solvent and Supercritical Carbon Dioxide

Abstract

Salvia miltiorrhiza (S. miltiorrhiza), also named as Danshen, is a traditional Chinese herbal medicine reported to possess anti-cancer and anti-inflammation activities, which can be attributed to presence of the major functional components tanshinones. The objectives of this study were to develop a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for determination of tanshinones in S. miltiorrhiza and comparison of extraction efficiency of solvent and supercritical CO₂. Results showed that a total of 6 tanshinones including 15,16-dihydrotanshinone I, 1,2,5,6-tetrahydrotanshinone I, cryptotanshinone, tanshinone I, 1,2-dihydrotanshinone I and tanshinone IIA could be separated within 18 min by employing a Metachem ODS-2 C18 column and a gradient mobile phase of 0.1% formic acid solution (A) and acetonitrile (B) with flow rate at 1 mL/min, detection wavelength at 280 nm and column temperature at 25°C. The highest yield of total tanshiones (2869.9 μg/g) extracted by supercritical CO₂ was attained at 70°C and 400 bar. For solvent extraction, the highest yield of total tanshinones was obtained by methanol or ethanol, which amounted to 3103.1 μg/g and 3021.6 μg/g, respectively. For future large production of tanshinones from S. miltiorrhiza, ethanol can be adopted to replace methanol and supercritical CO₂ amid its safety nature and higher yield than supercritical CO₂