Studies On The Total Flavonoids Extraction Techniques, Extracts Activities And Fingerprint Of Hawthorn (Crataegus Pinnatifida)

Hawthorn (Crataegus pinnatifida), referring to the Rosaceae family, has beenused as herbs and edibles for a long time and has been planted widely in China. Manyresearches showed that Hawthorn has many biological activities such as reducingblood pressure and total plasma cholesterol, treating the early stages of congestiveheart failure, anti-arteriosclerosis, anti-oxidation, anti-cancer and improvingimmunity of corporeity. These benefits were attributed to several effectivecomponents such as flavonoids, procyanidins and triterpene acids etc. However, theprevious researches mainly focused on the simple extraction techniques and theprocessing of crude extracts, as a result, the utilization of hawthorn and its effectivecomponents was badly affected. In this paper, An analytical method of totalflavonoids was established; SFE-CO₂ was used to extract the effective components ofhawthorn, and the extraction conditions of total flavonoids were optimized; Theantioxidant activities of different extracts were studied and compared; A systematicclassification method was developed for the quality assessment of hawthorn based onchemical fingerprints and HPLC-DAD-MS. The main results in the paper areconcluded as follows:1. The NaNO₂-Al(NO₃)₃ colorimetric method combined with the improvedpolycaprolactam purification was developed for the determination of totalflavonoids in hawthorn. A fast analytical method has been established by optimizingthe conditions for colorimetry and reducing the interference of impurity. The resultsshowed that the developed method could eliminate the interference of impurity andwas a better method for the determination of total flavonoids in hawthorn with highprecision and good reproducibility.2. Optimum conditions of the extraction of the total flavonoids from hawthornwith ethanol reflux were studied by using orthogonal experiment design. The resultsshowed that the optimum conditions for the extraction with water bath was 2h at70℃, the ratio of solvent to material of 20:1, 70ï¼…ethanol as the solvent, extraction 2 times. The yield of total flavonoids was 3.97ï¼…at the optimum condition.3. The SFE-CO₂ technique used to extract total flavonoids in hawthom wasoptimized. The optimization study involved a central composite rotatabledesign(CCRD) and response surface methodology(RSM); the design was used tostudy the three factors with a potential influence on the extraction process, namely:extraction pressure, extraction temperature and extraction times. The results showedthat the optimum conditions were as follows: 36.6Mpa, 47.8℃and 4 times(40mL95ï¼…aqueous-ethanol and 2 hours). The yield of total flavonoids was 0.61ï¼…at theoptimum conditions.4. The anti-oxidant effects of different Hawthom were studied in vitro models byusing DPPH and pyrogallol autooxidation methods. The results showed that they allhad anti-oxidant effects, and the anti-oxidant effects had a positive correlation withconcentration, and the anti-oxidative activities of the extract decreased in the order ofethanol bath, SFE-CO₂, water. The ethyl acetate part possesses the strongestscavenging effects on DPPH radical by compared with other polarity parts.5. The HPLC-DAD-MS method was used to study the HPLC fingerprint ofHawthorn. Meanwhile, seven common peaks were identified by compared their UVand MS spectra with the references. Satisfactory results were obtained by calculatingthe similarity. This method provides complete information for the identification ofHawthorn, and benefits for the quality control of Hawthorn. In addition, the study canpromote the utility of HPLC-DAD-MS in the analysis and identification of complexcomponents in herbal materials.