Study On Optimum Conditions Of Extracting Glutathione By Reversed Micellar

It has a promising profit that extraction of biological molecule by reversed micelles, for the more mild operational condition, lower cost ,easy operating,continuous producing and solvent recycling. Glutathione is a active trip peptide,used in the many fields such as medicine, biology, chemistry because of its excellent antioxidant.In this paper a new P204/ n-octyl alcohol reversed micelles was used to extracting GSH and the extraction principle was studied: There is electrostatic interaction between amidos of glutathione taking positive charge and electronegative oxygen of anion surfactant, resulting in glutathione can be extracted into reversed micelles.The oxidizing half-life of glutathione in the P204/ n-octyl alcohol reversed micelles is 10.1h. When comparing with that exposed in the air, it increased 0.8h and the increment rate was 7.3%.Dissociative amidos in alanine, lysine and aspartic acid competing electronegative oxygen with amidos in glutathione. The more dissociative amidos were, the greater combining force was, so the stronger competition is. Moreover, when volume of one amino acid is smaller than that of another, its competition is also stronger.Glutathione extraction rate (E) depends not only on the pH value of aqueous phase but also concentration of positive ions, concentration of P204, extracting time and W0. While pH value is upon 2.0, extraction rate is decreased with its raise because glutathione molecule's electric charge decreases and the electrostatic interaction between polar terminal of P204 and glutathione is weakened. While w0 is 10, the E gets a maximum which is 28.3%. The effect of difference positive ions on extraction is K+>Na+>Ca2+>NH4+ because of the alkalescence of these ions in the solution is strengthened. The results of L16(45) orthogonal tests showed the optimum conditions are that pH value of aqueous phase is 2.0; [K+] is 0.1mol/L; [ P204] is 0.16mol/L and extraction time is 15min. With the optimum conditions, glutathione extraction rate gets 33.1%, when extracted with reversed micelles twice; the total extraction rate gets 49.7%. The effect of these factors is [K+] >W0>pH value of aqueous phase> [P204]> extracting time.There are many factors can affect glutathione reextraction rate (EËŠ ) such as the pH value of the reextracting aqueous phase, concentration of positive ions and reextraction time. While the pH value of the aqueous phase is during 9.0 and 12.0, EËŠis increased with it's increasing and invariable at last. While concentration of Ca2+ varied from 0.2mol/L to 0.6mol/L, EËŠis increased with the concentration of Ca2+ because the interaction is weakened by increased Ca2+. It is showed by the results of L9 (43) orthogonal tests that the optimum conditions are that the pH value of the reextracting aqueous phase is 11.0; [Ca2+] is 0.6mol/L; the ratio of organic phase to the reextracting aqueous phase is1:3 and reextraction time 45min. With the optimum conditions, glutathione reextraction rate is 52.6%. The effect of these factors is reextraction time >pH value of the reextraction aqueous phase> [Ca2+]> ratio of the two phases...