| ObjectiveMicroctis Folium, the dried leaf of Microcos paniculata L., is rich in South China, especially in Guangdong and Guangxi. It is used to treat food stagnation, cold fever, jaundice and so on, with the effect of resolving food stagnation, and clear heat and disinhibit dampness. It also can make as herbal tea. In recent pharmacological research, Microctis Folium have antipyretic, promoting digestion, jaundice, anti-inflammatory and lipid-lowering effect. The study is carried out by high performance liquid chromatography (HPLC), near infrared spectroscopy (NIRS), and chemometrics method, to establish an economic, simple and rapid method for the quality of Microctis Folium.MethodsTaking epicatechin, vitexin, isovitexin, narcissoside as index components, adopting the method of HPLC to determinate the contents of the four compounds of49batches of Microctis Folium samples collected from different areas. Methodological investigation also has been examined. In order to explore a quickly derermination of index components, we established multivariate calibration models among NIRS and derermination of HPLC by using NIRS combined with Partial Least Square(PLS).ResultsThe HPLC quality evaluation method was established, which is feasible, reproducible and accurate, with the methodological study confirmed. It can be used to the quality control for Microctis Folium.The content determination showed that the contents of epicatechin, vitexin, isovitexin, narcissoside and total flavonoids in Microctis Folium sample collected from different areas were different. The contents of epicatechin is between0.0260%to0.4514%, vitexin is0.0242%to0.1900%, isovitexin is0.0218%to0.2916%, narcissin is0.0448%to0.5024%, and total flavonoids is 0.1338%to1.1114%. It shows that the highest content was narcissin, the second was isovitexin (except for S15,25samples), the third was vitexin (except for S23,24,37,42samples), which the epicatechin is different. It provided that using the content of vitexin to control the quality of Microctis Folium has its scientific in existing quality standards of the "Chinese Pharmacopoeia". These results showed that the quality of Microctis Folium is affected by same influence of factions such as growth environment, havest and process, storage condition. We should use multi-index comprehensive evaluation to assess the internal quality of Microctis Folium. These results provide experimental basis for optimum selection of crude drug of Microctis Folium.The NIRS data was processed with9point smoothing and longitudinal coordinate normalization, which to establish calibration model of epicatechin, vitexin, isovitexin and narcissin by analyzing correlation coefficient (R2) and root mean square error (RMSE).Calibration model was established by the partial least squares method (PLS) in SAS JMP Statistical Discovery V9.0.2. The modeling band of epicatechin, isovitexin and narcissin was7800-9999cm-1, and vitexin’s was7100～7800cm-1, with NIRS data processed with9point smoothing and longitudinal coordinate normalization. The model correlation coefficient (R2) of epicatechin, vitexin, isovitexin and narcissin were0.9549,0.9312,0.9287and0.9349, while RMSE were0.737,0.604,0.787and0.810.The fitting-linear correlation coefficients (R2) of epicatechin, vitexin, isovitexin and narcissin were0.9276,0.9084,0.9252and0.9305. It showed that the deviation values between NIRS prediction and HPLC determination was small, and the model had good prediction ability, which can be rapid prediction for its contents. Conclusions:NIRS combined with chemometrics methods, which was determined the contents of epicatechin, vitexin, isovitexin and narcissin, was simple, accurate, high sensitivity, and low detection cost. It is conducive to the quality evaluation of Microctis Folium. |
PDF Full Text Request