| Objectives:To establish an HPLC method for determination of main constituents and the fingerprint of Herba Siegesbeckiae before and after traditional preparation in order to analyze the influence caused by the way of preparation, and also optimize the quality evaluation system; To optimize traditional drying process of Herba Siegesbeckiae based on the established quality evaluation system; To use electronic nose to establish a fast detection for Herba Siegesbeckiae before and after traditional preparation for the first time, and reveal the varying pattern of the odors of Herba Siegesbeckiae before and after traditional preparation.Methods:(1) To establish an content determination method of total terpene in Herba Siegesbeckiae before and after traditional preparation by UV-VIS spectrophotometry;(2) To establish content determination methods of kirenol, darutoside and darutigenol by HPLC and also compare their difference before and after traditional preparation;(3) To optimize the drying process with the content of kirenol, extract and total terpene as indexs together with the multi-index scoring method, and determine the parameters of drying process;(4) To establish the chromatographic fingerprints of Herba Siegesbeckiae before and after traditional preparation, and use the similarity evaluation software to match peaks. To compare the fingerprints before and after traditional preparation in order to reveal pharmacodynamic material basis.(5) To optimize the detection method by electronic nose through orthogonal test and detect Herba Siegesbeckiae different from times of preparation, places of origin, storage time.Results:(1) The optimized extraction process is:refluxing by40mL50%methanol three times, and2h each time;(2) Established the content determination methods of kirenol, darutoside and darutigenol, the regression equation:Y=642300X-9225.3(r=1); Y=293107X+5078.2(r=0.9998); Y=328422X+3980.4(r=1). These methods are found to have satisfactory accuracy, stability and reproducibility.(3) The optimized drying process:forcing air drying for4h in50℃, and the layer thickness is0.8kg/m2.(4) The number of common peaks in fingerprint of Herba Siegesbeckiae before preparation is18and the similarity of Herba Siegesbeckiae from different orgins is above90%. (5) Established the detection method of Herba Siegesbeckiae:the sample quantity is0.5g(40mesh screen), and the headspace temperature is60℃, and incubation period is1800s. This method can differ Herba Siegesbeckiae with different times of preparation, origins, storage time by odors.Conclusions:The method established for quality evaluation has excellent specificity and reproducibility for the quality control of Herba Siegesbeckiae before and after traditional preparation. The content of main constituents of Herba Siegesbeckiae has a significant change before and after preparation based on results of content determination and fingerprints. Through the established muli-indexes quality evaluation system, the drying process is optimized. This study completed the digitization and standardization of characteristics of Herba Siegesbeckiae before and after traditional preparation, and established a detection method and recognition mode by electronic nose, thus provided reasons for differences of effects of Herba Siegesbeckiae before and after preparation based on chemical constituents. |
