Study On Extraction,Purification And Application Of The Flavonoids From Dandelion

The extraction and purification technology of the total flavonoids from dandelion was studied in this paper; the extracted flavonoids were analyzed and detected through UV spectrophotometry and HPLC; extractive of flavonoids from dandelion was added to the tobacco and the effects on the improvement of cigarette’s quality and transfer rate were tested at the same time. The main results were as follows:1. The reliability of UV spectrophotometry method on dandelion’s flavonoids was studied. The results showed that the wavelength was 510nm, RSD of precision was 1.89%, RSD of repeatability was 0.55%, RSD of precision and repeatability were less than 2%, and within the error range. And RSD of stability was 2.91%, measurement should be followed immediately after 20 minutes’ reaction to assure the stability of the results.2. The microwave-assisted extraction method and ultrasonic-assisted extraction were employed to extract the total flavonoids from dandelion and extraction parameters were optimized by the single factor test and orthogonal experiment. The optimum extraction parameters of microwave-assisted method were:ethanol concentration was 75%, solid-liquid ratio was 1:35, extraction time was 15min, extraction power was 700W, the yield was 7.09%. The optimum extraction parameters of ultrasonic-assisted method were:ethanol concentration was 85%, solid-liquid ratio was 1:30, ultrasonic time was 35min, ultrasonic temperature was 60℃, the yield was 7.55%.3. Resin was used to purify the flavonoids from step 2. Polyamide resin was selected as the preferable resin by static adsorption and elution test. The optimum adsorption conditions were:the value of pH was 6, the sample volume was 20.00mL; the optimum elution conditions were:ethanol concentration was 90%, the temperature was set at 30℃; the optimum elution conditions were:sample concentration was 2.65mg/mL, the sample solution flow rate was 2.0mL/min, flow rate of eluent was 1.5mL/min.4. The content of total flavonoids from step 2 and step 3 was determined by using UV spectrophotometry and the results showed that content of flavonoids from step 2 which was not be purified by resin was 21.07%, the content of flavonoids from step 3 which was purified with resin was up to 47.89%. The content of quercetin and luteolin, which were the main elements in extractive, were analyzed by HPLC before and after purification, and it showed that the content of quercetin from the extractive which was not purified by resin was 0.23%, luteolin was 0.55%; while quercetin purified by resin was up to 3.98%, luteolin was up to 4.07%. It was obvious that the total flavonoids and main ingredient content had improved after purification.5. The antioxidant capacity of total flavonoid from dandelion was studied by investigated radical scavenging rate of DPPH. The results showed that DPPH radical scavenging rate increased with the rise of the extractive’s concentration, and the capacity of scavenging DPPH radical of flavonoids which was purified by resin was better than before, and was stronger than BHT but weaker than Vc.6. The effects of extractive on improvement of cigarette’s quality and transfer rate were investigated. It showed that cigarettes which added appropriately extractive were more fragrant, sweet-flavored and fluid, and the extractive also alleviated the irritation of the throat. It was obvious that extractive improved quality of cigarette flavor and could be used as effective alternative material plant type cigarette additives. It was studied that the dandelion flavonoids extracts’transfer rates in cigarettes. The basic law of the transfer rate of cigarette added extractive was consistent with cigarette added rutin standard. The transfer rates of Cigarette A, B and C are 4.23%, 4.18% and 4.09% respectively; the filter mobility had not been detected; the filter rejection rate and the mainstream smoke transfer rate were both extremely low.