黄秋葵中黄酮类化合物提取方法优化及总黄酮抑菌效果研究

Optimization by Response Surface Methodoloy of Flavonoids Extraction and the Antibacterial Activities of the Total Flavonoids From Okra(Abelmoschus esculentus L.)

为高效提取黄秋葵中黄酮类化合物,本试验以黄秋葵中的4种主要黄酮类化合物和黄秋葵总黄酮含量为响应值,通过单因素试验和Box-Behnken响应面试验进行提取工艺优化,并采用牛津杯法考察黄秋葵总黄酮对6种常见致病菌的抑菌活性。结果表明,在提取温度37℃、提取时间20 min、乙醇浓度70%、料液比1∶25 g·mL^(-1)的条件下,可对黄秋葵中总黄酮以及槲皮素-3-龙胆二糖苷、槲皮素-3-O-木糖(1→2)-葡糖苷、异槲皮苷,槲皮素-3-O-(6-O-丙二酰)-葡糖苷4种有效成分进行提取测定。优化后所得总黄酮实际含量为4576.1μg·g^(-1),其中槲皮素-3-龙胆二糖苷为2403.7μg·g^(-1)、槲皮素-3-O-木糖(1→2)-葡糖苷为516.5μg·g^(-1)、异槲皮苷为1170.7μg·g^(-1)、槲皮素-3-O-(6-O-丙二酰)-葡糖苷为485.2μg·g^(-1),接近预测值,表明该提取工艺具有可行性。抑菌试验结果表明,黄秋葵总黄酮对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌等细菌和白假丝酵母、黑曲霉及黑根霉等真菌均有抑菌活性,各菌的最小抑菌浓度(MIC)分别为5.0、3.8、5.0、3.8、7.5和7.5 mg·mL^(-1)。本研究优化了黄秋葵总黄酮和各有效成分的提取方法,证明了黄秋葵总黄酮具有较好的抑菌效果,为进一步开发利用黄秋葵黄酮类化合物提供了理论依据。

To extract flavonoids more efficiently,the contents of four individual main flavonoids and the total flavonoids of okra(Abelmoschus esculentus L.)were obtained using single-factor test and response surface methodology with Box-Behnken design.The antibacterial activities of the total flavonoids in okra against six common pathogens were also investigated by the Oxford cup method.The content of the total flavonoids of okra was 4576.1μg·g^(-1),including quercetin-3-gentiobioside(2403.7μg·g^(-1)),quercetin-3-O-[β-D-xylosyl-(1→2)-β-D-glucoside](516.5μg·g^(-1)),isoquercetin(1170.7μg·g^(-1))and quercetin-3-O-(6-O-malonyl)-β-D-glucoside(485.2μg·g^(-1))under the optimal extraction conditions,that the extraction temperature 37°C,extraction time 20 min,ethanol concentration 70%,and solid-to-solvent ratio 1∶25 g·mL^(-1).The values of the flavonoids were close to the predicted value,indicating the feasibility of the extraction process.The extracted flavonoids exhibited good antibacterial activities against Escherichia coli,Staphylococcus aureus,Bacillus subtilis,Canidia albicans,Aspergillusniger niger and Rhizopus nigricans.The minimum inhibitory concentration(MIC)was 5.0,3.8,5.0,3.8,7.5 and 7.5 mg·mL^(-1),respectively.The results provided a theoretical basis for the further development and utilization of okra flavonoids.