Donglai Ma^{1, 2}, Xinrui Li¹, Meng Wu¹, Yuxin Jia¹, Yongxing Song^1,, Ning Liu^3,, Si Li^1,

The metabolites of Lycii cortex from L. chinense (CM), L. barbarum (BL), and the related species L. barbarum var. auranticarpum (BA) and L. ruthenicum Murr. (RM) were analysed to determine their quality differences in the metabonomic method. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was used to compare the metabolites in Lycii cortex of different origins. Partial least-squares discriminant analysis and cluster heat map analysis were used to identify the difference in metabolites, and KEGG pathway enrichment analysis was performed. The correlation between different metabolites and antioxidant activity (DPPH, ABTS, and FRAP) was analysed by the grey correlation degree method. The results showed that the Lycii cortex of different sources can be obviously distinguished, and the metabolite contents of BA, CM, and BL samples were similar, obtained 242 variables and 15 Differential metabolites (VIP > 1). Kukoamines were the most abundant and had higher contents in CM, BL, and BA samples, while the content was lower in RM samples. It was determined that the differential metabolites of the four varieties of Lycii cortex mainly came from tryptophan metabolism, sphingolipid metabolism, isoquinoline alkaloid biosynthesis, and phenylalanine metabolism with KEGG database. There was a significant correlation between the metabolites of Lycii cortex and antioxidant activity. The correlation coefficient between 103 metabolites and the antioxidant activity was > 0.90, and that between kukoamines was 0.98. Metabonomic is a reliable system biology approach for understanding the quality difference of Lycii cortex, and searching for new drug sources.

Lycii cortex, ·UHPLC-Triple TOF-MS, ·metabolomics, KEGG pathway