Enrichment Of Total Flavonoids From Flos Populi Extracts And Establishment Of HPLC Fingerprint

Flos Populi is a traditional Chinese medicine prepared from the male inflorescence of Populus tomentosa Carr. or Populus canadensis Moench (Salicaceae family). Traditionally, it is developed for detoxication and relief of fever. Flos Populi is included in PRC veterinary Pharmacopoeia. Pharmacological studies have shown that Flos Populi is an excellent source of total flavonoids used as an antidiarrheal drug, but there are no researches about enrichment and quality control, it has restricted utilization of the resource. In this study, extraction and enrichement process was optimized; a fingerprint quality control method was established. It has provided a reference for industrial.Box-Behnken design was used to optimize the extraction conditions of total flavonoids from Flos Populi. The effects of four independent variables in terms of extraction time, temperature, ethanol concentration, and the ratio of liquid to material on the flavonoids yield were determined and the optimal conditions for flavonoids were evaluated by means of response surface methodology. Correlation analysis of the mathematical regression model indicated that a quadratic polynomial model could be employed to characterize extraction process for the total flavonoids. Response surface plots showed that these independent variables significantly influenced the extraction yield of total flavonoids. The optimal extraction parameters to obtain the highest total flavonoids yield were temperature of94.66℃, ethanol concentration of45.92%, the ratio of liquid to material of18.55:1(mL/g), and time duration of2.27h. The average experimental total flavonoids yield under the optimum conditions was found to be53.08±0.43mg/g, which agreed with the predicted value of52.04mg/g. The extraction method was applied successfully to extract total flavonoids from Flos Populi.On the basis of optimum extraction processing condition, enrichment and purification of total flavonoids from Flos Populi extracts were studied using five macroporous resins. The static tests indicated that NKA-9resin was appropriate and its adsorption data were well fitted to the Langmuir and Freundlich isotherms. To optimize the separation process, dynamic adsorption and desorption tests were carried out. The optimal adsorption parameters were initial concentrations in sample solution of7.64mg/mL, pH of5.0, sample loading amount of2.3BV, flow rate of2BV/h, temperature of25℃.The optimal desorption parameters were deionized water and20%ethanol each5BV, then60%ethanol of10BV, flow rate of2BV/h. After one run treatment with NKA-9resin, the content of total flavonoids in the product increased from11.38%to53.41%, and the recovery yield was82.24%. The results showed that NKA-9resin revealed a good ability to enrichment total flavonoids from Flos Populi, and the method can be referenced for the enrichment of total flavonoids from other materials.Aim To develop HPLC method for quality control of Flos Populi. According to HPLC method, the experiment investigated3kinds of chromatographic column of the Diamosil C18column (4.6mm x250mm,5microns), Wondasil C18column (4.6mm x150mm,5microns), the Unitary C18column (4.6mm x250mm,5microns), and4kinds of mobile phase elution system as Acetonitrile-0.1%HCOOH, Acetonitrile-1%HAc solution, Methanol-1%HAc solution, Methanol-H2O solution, as well as the different wavelength. Optimized the gradient elution procedure with good peak position, peak shape and ideal chromatogram separation degree, finally established the finger-print methods of Flos Populi extract. The methodological evaluation showed that this method had a good precision repeatability and reproducibility.In this research, the response surface method was used to optimize the extraction of total flavonoids from Flos Populi for the first time; and it first adopted macroporous resins to enrichment of total flavonoids from Flos Populi extracts. A fingerprint quality evaluation method is established to comprehensively control the quality of Flos Populi. This study has theoretical significance and practical value, as well as the technology of enrichment by macroporous resin and fingerprint played an exemplary role in veterinary medicine application.