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

Li-Ying Hsieh ^a,1, Hsiu-Hui Chan ^a,1, Ping-Chung Kuo ^b,1, Hsin-Yi Hung ^b,**, Yue-Chiun Li ^c, Chao-Lin Kuo ^d, Yong Peng ^e, Zhong-Zhen Zhao ^f, Daih-Huang Kuo ^g, I-Wen Sun ^a, Tian-Shung Wu ^b,g,*

^a Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan

^b School of Pharmacy, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan

^c Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan

^d Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung 401, Taiwan

^e Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100094, China

^f School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China

^g Department of Pharmacy, College of Pharmacy and Health Care, Tajen University, Pingtung 907, Taiwan

Lycii Fructus, a solanaceous drug, is widely used as functional foods and in Traditional Chinese Medicine. Samples collected from different regions of China have been found to be not identical in chemical compositions which might affect the biological activities. Althoughmany chromatographic and spectrometric methods have been reported to determine the concentration of betaine and other bioactive amino acids, disturbance resulted from other polar substances with low UV-absorbance and expensive mass facilities reduced the applicability of these techniques. In the present study, the strong cation exchange solid phase extraction procedure incorporated with 1H NMR was successfully developed as a rapid and reliable method that can simultaneously determine betaine, citric acid, threonine, alanine, and proline

in various Lycii Fructus. In addition, ERETIC 2 method based on PULCON principle was also applied and compared with conventional method. This feasible and practical method offers a very powerful tool for the quality control of commercial Lycii Fructus from different sources.

Keywords: ERETIC 2, Betaine, 1H NMR, Lycii Fructus, PULCON