响应面法优化爵床总黄酮的提取工艺及理化性质

目的:采用响应面法优化爵床总黄酮的回流提取工艺，并对其进行稳定性和抗氧化活性考察。方法:以爵床为药材，选择不同的料液比、乙醇体积分数、提取时间和提取温度作为单因素，以爵床总黄酮提取量为指标，进行单因素考察；继而运用响应面法进行优化，获得最佳提取工艺。通过设定不同的温度、光照、pH以及金属离子等条件，考察爵床总黄酮的稳定性；通过对DPPH自由基清除率进行测定，评价其抗氧化活性。结果:爵床总黄酮提取工艺的最佳条件，料液比1:23 g/mL、乙醇体积分数55%、提取时间20 min、提取温度70 ℃；提取量为9.02 mg/g。稳定性试验结果表明，爵床总黄酮在30~90 ℃、pH4~9条件下较稳定，在金属离子Cu2+、Fe2+、Zn2+、Al3+、Ba2+条件下较不稳定。DPPH自由基清除率结果表明，爵床总黄酮对DPPH自由基的IC₅₀为0.079 mg/mL。结论:响应面法优化爵床总黄酮回流提取工艺稳定、可靠，提取物具有一定的稳定性和抗氧化活性。

Extraction Optimization by Response Surface Methodology and Physicochemical Properties of Total Flavonoids from Rostellularia procumbens (L.) Ness

Objective: To optimize the reflux extraction technology by the response surface methodology and evaluate the stability and antioxidant activity of the total flavonoids from Rostellularia procumbens (L.) Ness. Methods: The best conditions of extracting total flavonoids from Rostellularia procumbens (L.) Ness were screened by the response surface methodology based on single factor experiments with the ratio of materials to liquid, ethanol volume fraction, extraction times and extraction temperature as factors with the yield of total flavonoids as index. Meanwhile, the stability was evaluated at different temperatures, light, pH and metal ions and the antioxidant activity was measured by scavenging of DPPH. Results: The results showed that optimal process obtained were as follows: Materials to liquid was 1:23 g/mL, ethanol volume fraction was 55%, extraction time was 20 min and extraction temperature was 70 ℃. The yield of total flavonoids was 9.02 mg/g. The total flavonoids from Rostellularia procumbens (L.) Ness under the optimal extraction process was stable at 30~90 ℃ and pH4~9 and not stable in metal ions of Cu2+, Fe2+, Zn2+, Al3+, Ba2+. IC₅₀ of total flavonoids from Rostellularia procumbens (L.) Ness to DPPH free radical was 0.079 mg/mL. Conclusion: The reflux extraction technology by the response surface methodology was rational and feasible and the extract exhibited good stability and antioxidant activity.