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Objective To identify new genes that correlate with prognosis of clear-cell renal cell carcinoma (ccRCC)
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OBJECTIVE: To determine the optimum ultrasonic-assisted extracting process of total flavonoids from Zingiber mioga by response surface methodology, and then study the antioxidant activity of the extract. METHODS: On the basis of single factor experiments, a 4-factor, 3-level Box-Behnken center-united experiment was conducted. The Box-Behnken experiment analyzed and optimized the processing conditions by response surface methodology, then the antioxidant activity of the extract was determined. RESULTS: The optimum conditions at ultrasonic power of 300 W were as follows treatment temperature 60℃, ethanol concentration 85.99%, liquid-to-solid ratio 98.08 mL·g-1, treatment time 15 min. Under the optimum conditions, the extraction rate of the total flavonoids was 37.01%, with a bias of 4.28% compared with the predicted value of 35.49%; the reducing power of the total flavonoids from Zingiber mioga at the concentration of 1.038 7 mg·mL-1 was equal to that of vitamin C of 56.60 μg·mL-1; the ·OH radical scavenging ratio of the total flavonoids from Zingiber mioga was 73.07%, the DPPH radical scavenging ratio was 65.72%, and the inhibition rate of anti-lipid peroxidation was 49.94%. CONCLUSION: The total flavonoids from Zingiber mioga can be developed as a new type of antioxidant agents, and regression analysis and parameter optimization of the extracting process can be conducted by using response surface methodology.
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OBJECTIVE: To optimize the ultrasonic-assisted extraction process of isoflavones from Pueraria lobata (Wild.) Ohwi using response surface methodology and measure the reducing power. METHODS: On the basis of single factor experiments, a four factors and five levels Box-Behnken experiment was designed. Then the reducing power of isoflavones was measured. RESULTS: The optimum conditions for the ultrasonic-assisted extraction process of isoflavone from Pueraria lobata (Wild.) Ohwi at ultrasonic power of 300 W were as follows: ethanol concentration 75%, liquid-solid ratio 35 mL · g-1, extraction time 35 min, and treatment temperature 50℃. Under the optimum conditions, the yield of polysaccharide from Pueraria lobata (Wild.) Ohwi was 24.18%, and the relative error between experimental value and predicted value was only 3.02%; the EC50 of the reducing power of isoflavones reached 0.135 mg · mL-1. CONCLUSION: The response surface methodology is suitable for regression analysis and optimization of the ultrasonicassisted extraction of polysaccharide from Pueraria lobata (Wild.) Ohwi.