Red ginseng has been gradually discovered to have pharmacological and physiological effects. It is well known that the most important bioactive components of ginseng are ginsenosides. The nootropic effect of ginsenosi...Red ginseng has been gradually discovered to have pharmacological and physiological effects. It is well known that the most important bioactive components of ginseng are ginsenosides. The nootropic effect of ginsenosides from nine different red ginseng extracts was evaluated here. Nine groups of mice were perfused with different concentrations of nine red ginseng extracts, respectively, and two groups of mice with distilled water. The nootropic effect of ginsenosides on mice was evaluated with behavior tests and a biochemical indicator study. The extracts were identified by rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry（RRLC-Q-TOF-MS）. Furthermore, principal component analysis（PCA） was used to analyze the contribution of chemical components from different ginseng groups. The extracts with the most and the weakest effective nootropic were found. It is notable that extract processing is a very important factor to decide pharmacological functions of ginseng extracts. As a conclusion, the most effective extract method for ginsenosides has been found. A panel of 13 ginsenosides has been screened out as chemical markers with nootropic effect, which include high level ginsenosides Ra0, Rb1, Rc, Rb2, Rb3, Re, Rd, and Rgl and low level ginsenosides mRb1, mRc, mRb2, mRd, and F2. Low level ginsenosides were first time to be discovered as possible nootropic compounds. This method may shed light on fast discovery of bioactive compounds of medicinal plants with low level compounds.展开更多
We have studied the fragmentation behavior of positive and negative ions of taxoi and 6/8/6 type taxoids, the influence of different substituents on fragmentation, and the correlativity between fragmentation patterns ...We have studied the fragmentation behavior of positive and negative ions of taxoi and 6/8/6 type taxoids, the influence of different substituents on fragmentation, and the correlativity between fragmentation patterns and structure by MS/MS technique with different ionization methods such as FAB-MS, ESI-MS, ete. We have also investigated in detail the fragmentation of various molecular-related ions, such as [M+H]+, [M+Na]+ and [M-H] ions, and the formation pathways of characteristic fragment ions. It has been found that there exists some competing reaction between the loss of C-13 side chain and decomposition by loss of acetic acid. In addition, by comparing CID spectra obtained with low- and high-energy collision, it is seen that CID-MS/MS with low-energy collision is more suitable for the study of the structural analysis of small molecules and drug metabolites. The experimental results demonstrate that MS/MS spectra can reflect more effectively the slight difference of structure between the related展开更多
文摘Red ginseng has been gradually discovered to have pharmacological and physiological effects. It is well known that the most important bioactive components of ginseng are ginsenosides. The nootropic effect of ginsenosides from nine different red ginseng extracts was evaluated here. Nine groups of mice were perfused with different concentrations of nine red ginseng extracts, respectively, and two groups of mice with distilled water. The nootropic effect of ginsenosides on mice was evaluated with behavior tests and a biochemical indicator study. The extracts were identified by rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry（RRLC-Q-TOF-MS）. Furthermore, principal component analysis（PCA） was used to analyze the contribution of chemical components from different ginseng groups. The extracts with the most and the weakest effective nootropic were found. It is notable that extract processing is a very important factor to decide pharmacological functions of ginseng extracts. As a conclusion, the most effective extract method for ginsenosides has been found. A panel of 13 ginsenosides has been screened out as chemical markers with nootropic effect, which include high level ginsenosides Ra0, Rb1, Rc, Rb2, Rb3, Re, Rd, and Rgl and low level ginsenosides mRb1, mRc, mRb2, mRd, and F2. Low level ginsenosides were first time to be discovered as possible nootropic compounds. This method may shed light on fast discovery of bioactive compounds of medicinal plants with low level compounds.
文摘We have studied the fragmentation behavior of positive and negative ions of taxoi and 6/8/6 type taxoids, the influence of different substituents on fragmentation, and the correlativity between fragmentation patterns and structure by MS/MS technique with different ionization methods such as FAB-MS, ESI-MS, ete. We have also investigated in detail the fragmentation of various molecular-related ions, such as [M+H]+, [M+Na]+ and [M-H] ions, and the formation pathways of characteristic fragment ions. It has been found that there exists some competing reaction between the loss of C-13 side chain and decomposition by loss of acetic acid. In addition, by comparing CID spectra obtained with low- and high-energy collision, it is seen that CID-MS/MS with low-energy collision is more suitable for the study of the structural analysis of small molecules and drug metabolites. The experimental results demonstrate that MS/MS spectra can reflect more effectively the slight difference of structure between the related
