A feasible and practical 1H NMR analytical method for the quality control and quantification of bioactive principles in Lycii Fructus

Lycii Fructus, a solanaceous drug, is widely used as functional foods and in Traditional ChineseMedicine. Samples collected from different regions of China have been found to be notidentical in chemical compositions which might affect the biological activities. Althoughmanychromatographic and spectrometric methods have been reported to determine the concentrationof betaine and other bioactive amino acids, disturbance resulted from other polarsubstances with low UV-absorbance and expensive mass facilities reduced the applicability ofthese techniques. In the present study, the strong cation exchange solid phase extractionprocedure incorporated with 1H NMR was successfully developed as a rapid and reliablemethod that can simultaneously determine betaine, citric acid, threonine, alanine, and prolinein various Lycii Fructus. In addition, ERETIC 2 method based on PULCON principle was alsoapplied and compared with conventional method. This feasible and practical method offers avery powerful tool for the quality control of commercial Lycii Fructus from different sources.