Studies On The Extraction, Isolation And Anti-oxidation Of The Flavonoids In Loutus Leaf

Lotus leaf contains lots of flavonoids. Flavone in lotus leaf is one of the most important physiological and active matters which has a better capacity of anti-oxidation and anti-caducity, curing blood vessel diseases, dropping level of cholesterin and so on. The extraction technics, anti-oxidative capacity, purification method and character of flavonoids in lotus leaf were mainly studied in this paper and the results were as follows:1. Optimum extraction technic of flavonoids in lotus leaf. The super fine crushing technique was put into extraction technic of traditional circumfluence and ultrasonic. By comparing two different extraction methods, it was an advantage that putting the super fine crushing technique and ultrasonic technique together, which could save time, save extraction energy, increase extraction efficiency and had higher applied value. The results showed that the optimum extraction conditions were size of material D50, the power of ultrasonic, ethanol concentration, solid/liquid ratio and the extraction time were 72.5μm, 200w, 70%, 1:20 and 9min respectively. The yield of the flavonoids was 5.35% under the appropriate conditions. Super fine crushing and ultrasonic could help the extraction of flavonoids constituents in lotus leaf.2. The study of anti-oxidative character of flavonoids in lotus leaf. The deoxidize ability, eliminative ability of O2-·and·OH, anti-oxidative ability were studied. It was found that lotus leaf flavonoids had higher deoxidative ability than Vc, which could eliminate O2-·and·OH obviously and restrain the oxidation of the lipin with the citric acid.3. The isolation of flavonoids of lotus leaf by macroporous resins. Macroporous resins had good advantages of big adsorption capability, good enrichment effect, mild desorption conditions, simple rebirth conditions, low costs, long using life and so on, which were adapt to purification of flavonoids. Three types of macroporous resin were compared in the ability of adsorbing and desorbing flavonoids of lotus leaf. The optimal adsorbent for flavonoids of lotus leaf was selected and its dynamic absorbing behavior was studied. The results showed that the AB-8 resin possessed higher absorption and desorption capacity and the optimum conditions were the flow rate of absorption solution, solution concentration, pH, elution solvent concentration, flow rate and dosage of elution were 3BV/h, about 2mg/mL, 6, 80% ethanol, 1.5BV/h and 3BV respectively. The product yield could be 59.31% by refinement of flavonoids from lotus leaf.4. The properties of flavonoids in lotus leaf. The flavonoids which had been purified were detected as flavonol and flavone by color reaction, TLC method (The solvent of TLC:methyl alcohol :chloroform: ethyl acetate: acetic acid=5:3:1:1), UV absorb spectrum and HPLC method (the conditions of Alltima-C18 column, moving phase : methyl alcohol: water: phosphor acid=45:55:0.2, 358nm of detecting wavelength, 0.6mL/min of flow velocity, 30℃of pole temperature).