Determination of the Eliminating Ratio of Polysaccharide to Hydroxyl Free Radical by Kinetics Spectrophotometry

OBJECTIVE The reaction dynamic of hydroxyl free radical (·OH) and salicylic acid was explored, the elimination ratios of polysaccharide extractive of Chinese traditional medicine to ·OH was determined by kinetic spectrophotometry. METHODS The dynamics curve of the reaction ·OH and salicylic acid was built by UV method. The elimination ratio of tangerine pee polysaccharide and ganoderma lucidum polysaccharide to ·OH was detemined based on the slope change of the graph．Repetitiveness and reliability of this method was tested by vitamin C. RESULTS The 50% elimination ratio (IC50) of polysaccharide extractive of tangerine pee and ganoderma lucidum to ·OH was 232.6 mg·L^-1 and 0.856 1 g·L^-1 respectively, the IC50 of vitamin C was 0.254 4 mmol·L^-1, RSD was 0.2％ (n＝5). CONCLUSION The method is sensitive, reliable, and it is suitable to be used to determine the elimination ratio of polysaccharide extractive of Chinese traditional medicine to ·OH.