Discrimination of Citrus reticulata Blanco and Citrus reticulata 'Chachi' as well as the Citrus reticulata 'Chachi' within different storage years using ultra high performance liquid chromatography quadrupole/time-of-flight mass spectrometry based metabolomics approach

Using ultra high performance liquid chromatography quadrupole/time-of-flight mass spectrometry (UPLC-QTOFMS) based metabolomics, we focused on developing a method for the comprehensive distinction between Citri Reticulatae Blanco Pericarpium(CRBP) and Citri Reticulatae Chachi Pericarpium (CRCP), as well as the CRCP within different storage years in this study. Through this, we hope to enhance Citri Reticulatae Pericarpium (CRP) Quality Control system. Using UNIFI software and an online database identified chemical components in the 3-30 years CRCP(40 batches) and CRBP (10 batches)samples, and multivariate statistical analysis methods and heat-map were applied to distinguish between CRCP and CRBP and CRCP in different storage years. The results showed that a total of 92 compounds were identified from CRCP and CRBP samples, most of which were flavonoids. Principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) indicated that it can effectively distinguish between CRBP and CRCP and various storage years CRCP, and 19 metabolites were identified as potential markers for distinguishing between CRBP and CRCP, and 15 potential markers showed a higher level of CRCP than CRBP. At the same time, 31 metabolites were identified to distinguish CRCP in different storage years, metabolite levels increased in 3-10 years and decreased after 15-30 years. Therefore, this approach can effectively distinguish between CRCP and CRBP and CRCP with different storage years, and may also provide a feasible strategy for the certification of Chinese herbal medicines from different species and storage years.