Abstract: In this study,a systematic chromatographic separation method was developed for the extraction and isolation of chemical components of Moutan Cortex.Pretreatment method of chromatographic separation was established through systematic liquidliquid extraction of Moutan Cortex methanol extract.The preparative chromatographic conditions of component Fr1.3 from Moutan Cortex was determined by systematic TLC screening method.The retention volume of targeted compounds was predicted in the step gradient elution conditions.The results showed that effective pretreatment method was liquidliquid extracting the methanol extract of Moutan Cortex using hexane,ethyl acetate sequentially.The systematic TLC methods can quickly select preparative column chromatographic separation conditions.The retention volume of the targeted compounds in Fr1.3 was accurately predicted under step gradient elution chromatographic separation conditions.Three times (with 1/3 theoretical sample loading,theoretical loading and maximum sample loading,respectively) of preparative chromatographic separation were carried out under the developed gradient elution conditions.The results showed that 6 pure compounds were successfully obtained from Fr1.3,in which the purities of 3 compounds were over 95% by HPLC.The method developed in this study can be used for the systematic chromatographic separation of other Chinese medicine components.

Key words: Moutan Cortex, systematic chromatographic separation, screening of chromatographic conditions, step gradient prediction, preparation chromatography