Determination of Salidroside and Betaine by 1H NMR for Quality Control of Xinnaoxin Commercial Products

A validated and sensitive H-1 NMR method was developed for the qualitative and quantitative analysis of the two main components of "xinnaoxin" prescriptions, salidroside and betaine. For the quantitative analysis, the characteristic signals for H-3 and H-5 of salidroside at delta 7.08 ppm (2H, J = 8.58 Hz), as well as the equivalent methyl groups of betaine at delta 3.12 ppm, were selected. The verification of the analytical method was accurate and in conformity with the guidance of the Chinese Pharmacopoeia. Furthermore, it has been applied to the quality assurance of products from different pharmaceutical companies. The results show that the content of salidroside in different products was satisfactory consistent with the results determined by high-performance liquid chromatography. This work implied that H-1 NMR represents a feasible alternative to liquid chromatography for quantitation of salidroside and was suitable for the more comprehensive quality control of "xinnaoxin" commercial products by the simultaneous quantification of salidroside and betaine.