Studies On The Extraction, Purification And Antioxidant Of The Flavonoids In Lotus Leaf

Lotus leaf is a sort of crude plant material for medicine and food. Flavonoids have health functions, such as antioxidation, fighting against senium, curing cardiovascular diseases, reducing blood fat and so on. In this paper,the best extraction, purification technologys and the antioxidant were researched and the flavonoids were identified by the color reactivity ,TLC,UV and HPLC.1. Microwave extraction: the power of microwave medium(about 400W), the period of microwave treatment 2 minutes, 60% ethanol, liquid material ratio 1:30. The rate of extracting of flavonoids in lotus leaf was 4.08% under this condition.2. Ultrasonic extraction: The optimal process conditions were percent of ethanol volume 50%, ratio of solid to liquid 1 : 20(g/mL), three extraction times, and extraction period as 20 min. The rate of extracting of flavonoids in lotus leaf was 4.85% under this condition.3. This is the first time to take the solvent-thermal extraction as the method to extract.: the ratio of material to liquid 1:30, 60% ethanol, extraction time 2h, the extraction temperature 90℃, to extract two times. Under this condition the lotus leaf flavononids extraction rate is 4.74%The ultrasonic extraction is best for the low energy cost, short time and high extraction rate.4. The optimal adsorbent for flavonoids of D101 macroporous resins was selected and its dynamic absorbing behavior was studied. The results showed that the D101 resin possessed higher absorption and desorption capacity and the optimum conditions were the flow rate of absorption solution, solution concentration, elution solvent concentration, flow rate and dosage of elution were lBV/h,about 1.89mg/mL, 80%ethanol,1BV/h and 3BVrespectively.The product yield could be 78.43% by refinement of flavonoids from lotus leaf. And we identify the compounds are flavonoids and flavonol.5. The scavenging effect of flavonoids in lotus leaf on hydroxyl radical was etudied. The result showed that it was easy for flavonoids in lotus leaf to scavenge free radical (OH). The antioxygenation of flavonoids in lotus leaf was studied in the oil. The graph of POV showed that the flavonoids in lotus leaf is a good antioxidant.