Quantitative Determination and Validation of Four Phenolic Acids in Salvia Miltiorrhiza Bunge using 1H-NMR Spectroscopy

Abstract

Background: Although chromatography and spectrometry-based methods have been used to analyse phenolic acids in Chinese traditional medicine Salvia miltiorrhiza Bunge (SMB), quantitative nuclear magnetic resonance (qNMR) has never previously been used to analyse fresh SMB root extracts. Objective: To establish a fast and simple method of quantitating danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B content in fresh SMB root using 1H-NMR spectroscopy. Method: Fresh SMB root was extracted using a 70% methanol aqueous solution and quantitatively analysed for danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B using 1H-NMR spectroscopy. Different internal standards were compared and the results were validated using highperformance liquid chromatography. Results: The established method was accurate and precise with good recovery. The LOD and LOQ indicated the excellent sensitivity of the method. The robustness was testified by the modification of four different parameters, and the differences among each parameter were all less than 2%. Conclusion: qNMR offers a fast, reliable, and accurate method of identifying and quantifying danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B in fresh SMB root extracts.