Study On The Secondary Metabolites Of Herbs With Chromatography

Plant which survive and thrive in a complex natural environment need to adapt to the non-biological factors stress, such as temperature, light, water, climate, nutrient. These factors would change the morphological structure and physiological metabolism. Plant phonological period is its seasonal changes corresponding environmental change, and reflects the stage of plant growth and development. The levels and types of plant secondary metabolites, which represent adaptive characters of natural selection during evolution, are decided by the species and habitats of Ephedra plants and also modulated by the picking times of day.In this paper, some factors influence quantitative changes of secondary metabolites in medicinal plants are researched by static headspace gas chromatography (SHGC) and high performance liquid chromatography (HPLC).OBJECTIVES1. Study the quantitative changes of ephedrine alkaloids of the pulverized Ephedra sinica plants with different particle sizes.2. Establish a method to determine the methyl chavicol contents of Agastache rugosus plants; Study the quantitative changes of methyl chavicol of Agastache rugosus plants picked at different times of day.METHODS1. Determination of alkaloids content of the pulverized Ephedra sinica plants with different particle sizes by HPLC.The separation was performed using a C18column (300mm×3.9mm id,10μm) with a Phenomenex C18guard column (4.0mm×3.0mm id). The mobile phase was water-phosphoric acid-triethylamine (100:0.1:0.1, v/v/v):methanol (98:2). The flow rate was1.0ml/min. The column temperature was30℃. The detection wavelength was210nm. The loading volume was20μl2. Determination of methyl chavicol of Agastache rugosus plants by SHGC.The separation was performed using an AT.OV-1301capillary column (50m×0.25mm×0.25μm, stationary phase:6%cyanogen propyl phenyl-94%dimethyl polysiloxane) with flame ionization detector (FID). Column temperature was maintained at50℃for3min, increased at10℃/min to150℃, then to240℃at5℃/min. Inlet temperature was kept at150℃, the FID was set at220℃. The headspace autosampler conditions were set as follows:oven temperature90℃and equilibration time45min.RESULTS1. The contents of alkaloids of Ephedra sinica pulverized in seven sizes fractions were determined. There were significant differences in the contents of alkaloids of Ephedra sinica smashed in different sizes. It indicated that the distribution of secondary metabolites in different particle sizes of pulverized Ephedra sinica also different.2. The contents of methyl chavicol of Agastache rugosus plants picked at seven different times of day were determined. There were significant differences in the contents of methyl chavicol of Agastache rugosus plants which pickect at different times of day. It indicated that the secondary metabolites which controlled by the environmental factors such as temperature and light would change in a day.