Objective: To investigate change of ginsenosides before and after co-decoction of Ginseng Radix et Rhizoma and Coptidis Rhizoma by ultra-flow liquid chromatography couple with quadrupole-time-of-flight mass-spectrometry(UFLC/Q-TOF-MS) and principal component analysis(PCA). Method: Chromatographic separation was performed on an ACQUITY UPLC T3 C18 column with a gradient elution of water-acetonitrile(containing 0.3% formic acid).Mass spectrometer equipped with electrospray ionization source was used as detector under negative ion mode.Difference of co-decoction of Ginseng Radix et Rhizoma and Coptidis Rhizoma

Ginseng Radix et Rhizoma decoction

Coptidis Rhizoma decoction(blank) were classified by PCA with Markerview 1.2.1 and other softwares. Result: Ten very different compound in three groups were found

contents of oleanolic acid and two unknown compounds significantly increased

while contents of 20-glucose-Rf

ginsenoside Rf

Ra3

Rb1

Ra2

Rb3

Rs2 significantly decreased. Conclusion: Samples of three groups are well classified by PCA in negative ion mode

it indicates that deglycosylation of ginsenosides may be material basis of co-decoction of Ginseng Radix et Rhizoma and Coptidis Rhizoma.