Research on Chlorogenic Acid and Flavonoids from Eucommia Ulmoides Leaves: Extraction, Isolation, Purification and Structural Identification
|School||Shanghai Ocean University,|
|Course||Food Science and Engineering|
|Keywords||Eucommia leaf Chlorogenic acid Flavonoids Separation and purification NMR Structural identification|
Eucommia (Eucommia ulmoides Oliv.) Is the beneficial health effects of medicinal plants in recent years, studies have found that the main component of Eucommia leaf Eucommia skin similar and have the same pharmacological effect, Eucommia leaf in order to further analyze the efficacy factor. Eucommia leaf, Eucommia leaf active ingredient extraction, separation, purification research; by thin layer chromatography and ultraviolet spectroscopy and electrospray ionization source - mass spectrometry and nuclear magnetic resonance detection of purified component structure analysis designed to determine the best extraction methods and found that the molecular structure of the active ingredients of Eucommia leaf, lay the foundation for the development and utilization of Eucommia leaf. The main results are as follows: 1. Eucommia leaf extract the active ingredients were used reflow method, ultrasonic, microwave method to extract the active ingredients of Eucommia leaves. Examine solid-liquid ratio, extraction time, ethanol concentration, solvent pH, extraction times on the extraction rate of the active ingredient, the orthogonal test, and ultimately comparing ultrasonic assisted reflux extraction. The optimum extraction technology: solid-liquid ratio of 1:10, extract temperature 80 ° C, 30% ethanol concentration, extraction solvent pH 5, the first ultrasonic extraction for 30 min, then reflux extraction for 30 minutes and repeat this operation once. Based on the optimal combination of technology, said take 5kg Eucommia leaf expanded trial, and ultimately Eucommia leaf extract the powder was 24%, which contains chlorogenic acid 22.29%, with 54.67% of the total flavonoids. Eucommia leaf crude extract separation and purification of First from the nine macroporous resin filter out the best adsorption resin NKA-II, static adsorption amount of chlorogenic acid 17.17mg / g, the adsorption rate was 90.92%, desorption rate was 75.63%, total flavonoids static adsorption capacity of 49.16mg / g, the adsorption rate was 90.44%, the desorption rate was 70.02%; static adsorption - desorption experiments show that the NKA-II resin is a rapid equilibrium resin, static adsorption 4h after reaching saturation adsorption, adsorption solution pH 4 with 70% ethanol for desorption solution can be chlorogenic acid, flavonoids eluted; followed by the dynamic adsorption - elution test results are shown the sample concentration chlorogenic acid 0.9012mg/mL, total flavonoids 3.4406mg/mL; the sample flow rate to 1.0 mL volume of the sample solution should not be more than 10 times the column volume. Optimization parameters based on small trials, expand the test. Weigh 600g of Eucommia leaf crude extracts by NKA-II macroporous resin separation, followed by pure water (18L), 30% ethanol (9L) and 50% ethanol (15L), 70% ethanol (12L), 90% ethanol (3L) with gradient elution obtained three components FA (64.93g), FB (36.06g) and FC (30.27g). The FA contains large amounts of chlorogenic acids, containing both FB in chlorogenic acids and contains flavonoids, FC containing mainly flavonoids, so the selection of the FA and FC purified. Weigh 25g of component FA, the use of ethanol - water (0%, 10%, 20%, 30%, 40%), gradient elution, polyamide column separation to obtain three fractions FA-1, FA-2 FA-3, collected 21 to 70 eluate was concentrated, and then purified by Sephadex LH-20 resin the component FA-2. Weigh 25g of the component FC, the use of ethanol - water (0%, 30%, 40%, 50%, 60%, 70%, 90%), gradient elution, five components of the polyamide column separation FC- 1, FC-2, FC-3, FC-4 and FC-5, # 27 to 73 tubes, 105 to 150 tubes # 295 ~ 315 tube eluate was concentrated after freeze-drying, and then by Sephadex LH- 20 resin to give the component FC-2, FC-3, FC-4. 3. Structure Elucidation of purified components by thin layer chromatography analysis showed that the spots of the four components of the system in Expand clear and focused component FA -2 Rf value of 0.265 is consistent with the chlorogenic acid standard, the components of the FC-2, FC-3, the Rf value of the FC-4 were 0.632,0.211,0.737, which belong to the flavonoid compound. UV spectroscopy results show that component FA-2, the maximum absorption wavelength is 324nm, the UV absorption characteristics with chlorogenic acid standard; component FC-2, FC-3, FC-4 flavonoids Typical UV absorption characteristic peaks with UVmax I were 349nm, 345nm, 367nm, with II UVmax 256nm, 254nm, 254nm, inference component FC-2 and FC-3 as a flavonoid glycoside compounds, the components of FC-4 may be quercetin prime. An electrospray ionization source - mass spectrometric detection and nuclear magnetic resonance detection infer, from of Eucommia leaf isolated purified four components are a single compound, compound FA-2 chlorogenic acid, compound FC-2 quercetin -3 - O-beta-glucoside compound FC-quercetin-3-O-acetyl-glucoside compound FC-4 quercetin.