Study On Extraction Of Hyperoside With CTAB Reversed Micellar

It has a promising profit that extraction of biological molecule by reversed micellar, for the more mild operational condition, higher extraction yield, lower cost and solvent recycling. Flavonoids which is always one of the hotspot looking for active biosubstance have many activities such as antioxidant,anticancer,antivirus etc., and it is possible to separating the flavonoid molecules through reversed micellar extraction because flavonoid molecule can be electriferous when the pH value is regulated to a right lever. In this paper the process of hyperoside extraction from extracts of Hypericum perforatum L. with CTAB reversed micellar system was studied systematically, and the cause and pattern of effect on hyperoside extraction and reextraction from different factors were discussed. It was showed that hyperoside molecule could be extracted by CTAB reversed micellar system because there is electrostatic interaction between polar terminal of CTAB and it in alkalescent solution,but not by AOT reversed micellar system because the molecular is electronegative. Hyperoside extraction rate (E) dependes not only on the pH value of aqueous phase but also species and concentration of ions, concentration of CTAB and phase ratio of organic to aqueous phase. While pH value is below 7.50, extraction rate is increased with it's raise because hyperoside molecule's electric charge increases and the electrostatic interaction between polar terminal of CTAB and hyperoside is strengthened. While the pH value is during 7.50 and 9.50, the E gets a maximum. While the pH value is upon 9.50, the E is decreased with the pH increasing because more and more OH-compete with hyperoside for combining to CTAB polar terminal. While the concentration of anion is under 0.2mol/L, the E increases with it. While the concentration of anion is 0.2mol/L, the E gets a maximum. While the concentration of anion is upon 0.2mol/L, the E is decreased with the increasing because the double ionization layer becomes thinner and electrostatic force is weakened. The effect of difference anions on extraction is I-pH>concentration of anions. For hyperoside extraction with CTAB reversed micellar, the optimum conditions are that pH value of aqueous phase is 7.50; species of anion Na2SO4; concentration of anion 0.2mol/L; concentration of CTAB 0.03mol/L; ratio of organic to aqueous phase 2:1 and extraction time 35mins. With the optimum conditions, hyperoside extraction rate gets 68.3%. There are many factors can affect hyperoside reextraction rate (EËŠ) such as the pH value of the second aqueous phase,species and concentration of anions,time and ratio of organic to aqueous phase. While the pH value of the aqueous phase is under 5.50, EËŠis increased with it's increasing, but while pH value is upon 5.50, EËŠis decreased with the increasing. The cause is that the change of the pH leads to the change of the hyperoside's solubility, and the electrostatic interaction between polar terminal of CTAB and hyperoside. EËŠis increased with the concentration of KI because the interaction is weakened by increased I-. It is showed by the results of L9(43) orthogonal tests that the effect of these factors is [KI]>pH value of the second aqueous phase>ratio of organic phase to the second water phase> reextraction time. For hyperoside reextraction, the optimum conditions are that pH value is 5.50; [KI] 0.5mol/L; the ratio of organic phase to the second water phase 1:4 and reextraction time 60mins. With the optimum conditions, hyperoside reextraction rate is 86.4%. With the optimum conditions, the total extraction rate of hyperoside with CTAB-Heptane-n-Octanol reversed micellar system is 59%. Hyperoside absorbs ultraviolet radiation at 258nm and 360nm. It is showed by the results of UV-TLC that there are 5 components in the unextracted aqueous phase. They are hyperoside,rutin,quercetin,hypericin and an unknown component. There are only hyperoside and rutin in the aqueous phase after the extraction of CTAB reversed micellar. The results lead to a conclusion that reversed micellar extraction technic is efficacious for purification of flavonol glycoside such as hyperoside.