Comparison of Anthraquinones, Iridoid Glycosides and Triterpenoids in Morinda officinalis and Morinda citrifolia Using UPLC/Q-TOF-MS and Multivariate Statistical Analysis

Roots of Morinda officinalis and Morinda citrifolia have been interchangeably used in traditional Chinese medicine. However, there is no experimental evidence to support this. In this study, a ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS)-based approach and a multivariate statistical analysis (MSA) were adopted to compare the difference in the chemical compounds present in the root extract of M. officinalis and M. citrifolia. There were 26 anthraquinones, 15 triterpenes, and 8 iridoid glycosides identified in the root extracts of M. officinalis, 30 anthraquinones, 1 triterpene, and 8 iridoid glycosides in the root extracts of M. citrifolia. Among these, 25 compounds presented in both plants. In addition, a principal component analysis (PCA) showed that these two herbs could be separated clearly. Furthermore, an orthogonal partial least squares-discriminant analysis (OPLS-DA) found 9 components that could be used as chemical markers to discrimination the root extracts of M. officinalis and M. citrifolia. In addition, the results of a Cell Counting Kit 8 (CCK-8) assay and cell colony formation assay indicated that methanol root extracts of M. officinalis and M. citrifolia showed no cell cytotoxicity to normal cells, even promoted the proliferation of normal liver cells. To our knowledge, this is the first time that the differences between the root extracts of M. officinalis and M. citrifolia (Hainan province) have been observed systematically at the chemistry level.