The intracellular kinase domains of the epidermal growth factor receptor(EGFR) in some tumor cells are significant targets for drug discovery.We have developed a new EGFR cell membrane chromatography(EGFR/CMC)-online-high performance liquid chromatography/mass spectrometry(HPLC/MS) method for screening anti-EGFR antagonists from medicinal herbs such as Radix Angelicae Pubescentis.In this study,the HEK293 EGFR cells with high expression of EGFR were used to prepare cell membrane stationary phase(CMSP) in the EGFR/CMC model.The retention fractions on the EGFR/CMC model were directly analyzed by combining a 10 port columns switcher with a HPLC/MS system online.As a result,osthole from Radix Angelicae Pubescentis was found to be the active component acting on EGFR like dasatinib as the control drug.There was a good relationship between their inhibiting effects on EGFR secretion and HEK293 EGFR cell growth in vitro.This new EGFR/CMC-online-HPLC/MS method can be applied for screening anti-EGFR antagonists from TCMs,for instance,Radix Angelicae Pubescentis.It will be a useful method for drug discovery with natural medicinal herbs as a leading compound resource.
SiCen WangMeng SunYanMin ZhangJie ZhangLangChong He
A rapid method for the simultaneous determination of berberine(BBR),matrine(MT)and oxymatrine(OMT)by nonaqueous capillary electrophoresis(NACE)was developed.Optimum separation of the analytes was obtained on a 50cm×50μm i.d.fused-silica capillary using a non-aqueous buffer system of 70mM ammonium acetate,7.0% acetic acid and 10% acetonitrile at 25kV and 20℃.The relative standard deviations(R.S.D.)of the migration times and peak areas of the three active components were 0.06%-0.20% and 0.12%-3.41% for berberine,0.11%-0.60% and 0.74%-1.63% for matrine,0.15% and 0.45% for oxymatrine,respectively.Detection limits of berberine,matrine and oxymtrine were 0.18μg/mL,4.08μg/mL and 4.16μg/mL,respectively.In the tested concentration range,good linear relationships(0.9992 for berberine,0.9988 for matrine and 0.9988 for oxymatrine)were observed.The linear calibration ranges were 0.45-360.0μg/mL for berberine,8.16-408.0μg/mL for matrine and 20.8-416.0μg/mL for oxymatrine.This method has been successfully applied to the phytochemical analysis of alkaloids extracts from two commonly used traditional Chinese herbal drugs:Sophora flavescens Ait.(Kushen)and Cortex phellodendri chinensis(Huangbai)and their medicinal preparations.
Yan-Hua Li,Zhuo Zhang,Wen Lu,Lang-Chong He School of Medicine,Xi’an Jiaotong University,Xi’an 710061,P.R.China
