Hb Xiao

Iridoid glucosides from Strychnos nux-vomica

From seeds of Strychnos nux-vomica three iridoids, 6-O-acetylloganic acid, 4-O-acetylloganic acid and 3-O-acetylloganic acid were isolated together with two known iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.

Mass spectrometry-based neurochemical analysis: perspectives for primate research

The analysis of neurochemicals from the brain represents a challenge for current analytical techniques due to a variety of factors, such as compositional complexity, limited amounts of sample and endogenous inferences. Advances in mass spectrometry (MS) provide great opportunities for the sensitive measurement of neurochemicals, offering benefits including simple sample preparation, broad capability for analysis of diverse compounds and rich structural information of analytes. Until recently, however, limited numbers of studies have reported on the analysis of small molecular neurochemicals, such as classical neurotransmitters, in part due to the difficulties in separation of polar molecules by using current chromatography techniques with MS-compatible conditions. By contrast, MS has become an indispensable tool for neuropeptide analysis , offering tremendous potential in the discovery of novel signaling peptides and biomarkers. This review covers recent advances in MS-based neurochemical analysis , including a comparison with related detection techniques, chromatographic separation and neuropeptide discovery. Issues relating to in vivo sample collection and sample preparation are discussed. To provide a wider view of the capability of MS in basic neuroscience and clinical research, we discuss MS-based neurochemical analysis conducted in different animal models and humans. We specifically highlight perspectives for the use of MS for brain functional studies and drug discovery in nonhuman primates.

New method for analysis of Chinese herbal complex prescription and its application

Traditional Chinese medicine (TCM) is a great treasure of China, the analysis of which is an arduous task. The viewpoint that all chemical constituents of Chinese herbal complex prescription should be analyzed as a black box is elucidated for the first time. Intelligent multi-mode multi-column chromatographic system (IMMCC) with its hybrids is the basic method and HPLC Unified Method is the breakthrough for the black box analysis. Dang-Gui-Bu-Xue-Tang was selected as a typical TCM and a systematic separation method from non-aqueous mobile phase to pure water mobile phase was put forward in order to convert unknown sample to known sample. The a,c values and UV spectra of 66 components ofAstragalus, 78 components ofAngelica and 71 components of Dang-Gui-Bu-Xue-Tang were obtained. Intelligent optimization and peak identification method and software for complex samples were developed and the optimum multi-step multi-binary gradient curve of mobile phase forAstragalus was ascertained. The maximum error and minimum error of predicted retention time for all components ofAstragalus are 8.62% and 0.05% respectively. All components ofAstragalus were compared with those ofAngelica and it is found that many components ofAstragalus are the same as those ofAngelica, while the contents of these components are different. Many components of Dang-Gui-Bu-XueTang are also the same as those ofAstragalus andAngelica with different contents.

Classification of structurally related compounds from Astragalus extract by correlation of the logk(w) and S

SummaryThe linear relationship between logkw andS derived from molecular interactions and statistical thermodynamics was investigated by four series of different polar probe solutes. For each series of similar polar solutes, structurally related compounds with similar dipolarity/polarizability and hydrogen bonding energy, a linear relationship between logkw andS was obtained. The more similar the solutes, the greater were the regression coefficients obtained. For two series of solutes with different strong polar groups resulting in different dipolarity/polarizability and hydrogen bonding energy, two parallel lines were observed in the logkw-S plots. Each line represented one series of compounds and the distance between them indicated the difference in the dipolarity/polarizability and hydrogen bonding energy. Based on the parallel lines implying information on structurally related compounds in the logkw-S plot, a method of classification of structurally related compounds was put forward and the linear logkw-S correlation for unknown components in nonaqueous RP-HPLC analysis ofAstragalus extract with isopropanol-methanol mobile phase was studied. Two nearly parallel lines were obtained in the logkw-S plot and two series of structurally related compounds were classified in this way.