Study On Inhibitor And Activator Of Tyrosinase

The synergistic activation on tyrosinase of psoralen cooperated with substrates, and the synthesis and optimization of ononin, as well as inhibition activity on tyrosinase and antioxidant activity were primarily studied in this thesis .Tyrosinase is a major enzyme, which controls the speed of melanin biosynthesis, the generating of hair and skin melanin, which is the key factor to black hair and whiten skin, can be promoted or prohibited by activating or inhibiting the tyrosinase. Tyrosinase plays a vital role in selecting cosmetic materials as a reagent.Psoralen was extacted by 75% ethanol water solution from Chinese traditional medicine psoralen . UV-Vis spectrophotometry method was selected to study the tyrosinase avtivity of psoralen which was in different concentration. The highest activation can be 44.9% when the concentration is 0.03 mg/mL . Different additives which can activate the tyrosinae , such as Cu²⁺,Fe²⁺,Mn²⁺,Zn²⁺and cysteine,affein,panaxcoside were selected to cooperate with psoralen to study the synergistic activation on tyrosinase . It indicated that Cu²⁺,Mn²⁺,Zn²⁺and cysteine were the right substances.Single factor method was selected to study the synergistic activation on tyrosinase of psoralen cooperated with all the right substances together, the highest activation can be 104.3 % , when the the concentration of Cu²⁺,Mn²⁺,Zn²⁺and cysteine was 0.1 mg/mL, 0.05 mg/mL, 0.1 mg/mL, 0.05 mg/mL respectively . Psoralen and the complex were proved to be a good additive to promote melanin biosynthesis in cosmetics and medicines .α-D-acetobromoglucose was used as sugar donor and formononetin,which was prepared by Deoxybenzoin route ,was used as nucleophilic reagent to synthesize ononin. Two Phase Transfer Catalysis (PTC) systems-solid-liquid PTC (SLPTC) system and liquid-liquid PTC (LLPTC) system were used to synthesize ononin. By comparing the yields, LLPTC system was selected and the highest yield can be 64.8 % by orthogonal experimentation. acetyl-ononin and ononin was isolated the HPLC purity can be 98.27 % and 98.36 % respectively.By using UV-Vis spectrophotometry method to determine the inhibitory rates of ononin and formononetin against tyrosinase and superoxide radical, it was found that the highest inhibitory rate of ononin against superoxide radical is lower than this of formononetin. The inhibitory rate can reach 45.2 % at the concentration of 1 mg/mL. And the inhibitory rate of ononin against tyrosinase can reach 51.7 % when the concentration is 0.05 mg/mL,. So ononin can be used in cosmetics as natural safe skin-lightening and anti-aging agent.