Characteristic Polyphenols in 15 Varieties of Chinese Jujubes Based on Metabolomics

Abstract

Background: Jujube is a homologous herb of medicine and food, and polyphenols are key in determining the functional effects of jujubes. Methods: In this study, characteristic polyphenols in 15 varieties of Chinese jujubes were investigated based on untargeted metabolomics. Results: The results showed that a total of 79 characteristic polyphenols were identified in the 15 varieties of Chinese jujube, and 55 characteristic polyphenols such as syringetin, spinosin and kaempferol were reported for the first time. Scopoletin (63.94% in LZYZ), pectolinarin (22.63% in HZ) and taxifolin (19.69% in HZ) contributed greatly and presented significant (p < 0.05) differences in the 15 varieties of Chinese jujubes. HZ was characterized by pectolinarin, erianin and wogonoside, while XSHZ, NYDZ and RQHZ, with similar polyphenol profiles, were characterized by (+)-catechin, combretastatin A4 and tectorigenin. JSBZ, HMDZ, TZ, JCJZ and HPZ had similar polyphenol profiles of galangin, isoferulic acid and hydroxysafflor yellow A. Conclusions: Metabolomics is critical in grasping the full polyphenol contents of jujubes, and the differences in the polyphenol profiles and characteristic individual polyphenols of the 15 varieties of Chinese jujubes were well analyzed by principal component analysis (PCA).