Studies On The Technics For Extracting And Purifying Flavonoids And Nuciferine In Lotus Leaves

Lotus leaf is a kind of natural plant can both edible and medicinal. There are various of bioactivators, such as flavonoids and alkaloidals. Hunan is one of the main production areas of lotus leaves. The variation of flavonoids and nuciferine content of lotus leaves, the extraction and purification methods of flavonoids and nuciferine were researched. The conclusions are as follows:1. By single factor test and orthogonal experiment design, the ultrasonic assisted solvent extraction process of total flavonoids from lotus leaves was studied. The total flavonoids of lotus leaves were determined by spectrophotometry. The test result shows that the better ultrasonic assisted solvent extraction process of total flavonoids in lotus leaves as following:raw material and solution ratio was1:35(g/mL), alcohol concentration was60%, ultrasonic power was175W, extracting temperature was50℃, extracting time was30min. Extraction rate of the flavonoids from lotus leaf of optimal test combination was9.13%.2.The adsorption and desorption effect that four kinds of macroporous resins (AB-8、HP-20、D-101、NKA-9),polyamide resin and silica gel affected the total flavonoids were compared. The results showed that AB-8macroporous resin had a good sorption rate and a high desorption rate. So it is suitable for the flavonoid separation and purification. Results of dynamic adsorption experiment and dynamic elution experiment of AB-8macroporous resin indicated that the concentration of initial solution was0.8mg/mL; the adsorption velocity was1.5mL/min; with70%alcohol as desorption agent, desorption velocity was1.0mL/min, separate and purify two times. The purity of flavonoids could reach75.16%.3. By single factor test and orthogonal experiment design, the condensation reflux-solvent extraction process of nuciferine from lotus leaves was studied. The nuciferine of lotus leaves were determined by spectrophotometry. The test result shows that the better condensation reflux-solvent extraction process of nuciferine from lotus leaves as following:raw material and solution ratio was1:30(g/mL), alcohol concentration was80%, extracting temperature was90℃, extracting time was3h. Extraction rate of the nuciferine from lotus leaf of optimal test combination was2.135mg/g.4. The adsorption and desorption effect that four kinds of resins (D-101macroporous resin、HPD-450macroporous resin、732positive ion exchange resin、 polyamide resin), affected the nuciferine were compared. The results showed that HPD-450macroporous resin had a good sorption rate and a high desorption rate. So it is suitable for the nuciferine separation and purification. Results of dynamic adsorption experiment and dynamic elution experiment of HPD-450macroporous resin indicated that the concentration of initial solution was0.4mg/mL; the adsorption velocity was1.0mL/min; with90%alcohol as desorption agent, desorption velocity was0.75mL/min. The purity of nuciferine could reach80.34%.5. The variation of flavonoids and nuciferine content of lotus leaves were researched. With the growth of the lotus leaf(May to July), the content of flavonoids and nuciferine gradual increase. At the mature period(August), the content of flavonoids was reached to94.21mg/g; the content of nuciferine was reached to2.152mg/g; When the lotus leaf was into the decline period(September to November), the content of flavonoids and nuciferine decreased. Through the multiple comparison found that in the mid-August the flavonoids content of lotus leaves were significantly higher than other months; But in the mid-August, mid-September, mid-October, and mid-November the nuciferine content of lotus leaves were not significant differences.