Shu-Ya Xu

Semen Cuscutae is commonly used in traditional Chinese medicine and contains a series of compounds such as flavonoids, chlorogenic acids and lignans. In this study, we identified different kinds of compositions by ultra-high-performance liquid chromatography (UPLC) coupled to electrospray ionization mass spectrometry (MS). A total of 45 compounds were observed, including 20 chlorogenic acids, 23 flavonoids and 2 lignans. 23 of them are reported for the first time including 6-O-caffeoyl-β-glucose, 3-O-(4′-O-Caffeoylglucosyl) quinic acid, etc. Their structures were established by retention behavior, extensive analyses of their MS spectra and further determined by comparison of their MS data with those reported in the literature. As chlorogenic acids and flavonoids are phenolic compounds that are predominant in Semen Cuscutae, in conclusion, phenolic compounds are the major constituents of Semen Cuscutae.

In traditional Chinese medicine practice, drying method is an essential factor to influence the components of Chinese medicinal herbs. In this study, an ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS)-based approach was used to compare the content of chemical compounds of mountain cultivated ginseng that had been natural air dried (LX-P) and vacuum freeze-dried (LX-L). Multivariate statistical analysis such as principal component analysis (PCA) and supervised orthogonal partial least squared discrimination analysis (OPLS-DA) were used to select the influential components of different samples. There were 41 ginsenosides unambiguously identified and tentatively assigned in both LX-L and LX-P. The results showed that the characteristic components in LX-P were ginsenoside Rb1, ginsenoside Rc, ginsenoside Rg6, dendrolasin, and ginsenoside Rb2. The characteristic components in LX-L were malonyl-ginsenoside Re, malonyl-ginsenoside Rb1, malonyl-ginsenoside Rc, malonyl-ginsenoside Rb1 isomer, malonyl-ginsenoside Rb2, malonyl-ginsenoside Rb3, malonyl-ginsenoside Rd isomer, gypenoside XVII, and notoginsenoside Fe. This is the first time that the differences between LX-L and LX-P have been observed systematically at the chemistry level. It was indicated that vacuum freeze-drying method can improve the content of malonyl-ginsensides in mountain cultivated ginseng.