Osmanthus fragrans (Lour) flower is a typical fragrant herb in eastern countries containing multiple bioactive compounds, the extract of which has been widely used as a natural antioxidant additive in food and cosmetics. However, the existing extraction methods use organic solvents during the extraction process, which is non-eco-friendly and harmful to human health. In this study, we introduce, to our knowledge for the first time, microwave-assisted deep eutectic solvent extraction (MA-DESE) to extract antioxidant components from O. fragrans flower. The MA-DESE procedure was optimised, validated, and compared with that of traditional solvent extraction by using response surface methodology. The maximum antioxidant activity of 101.81 mg Trolox equivalent/g of dry weight was achieved at the following optimum MA-DESE parameters: microwave power, 497.12 W; microwave treatment time, 59.03 s; and solid–liquid ratio, 31.14 mL/g. In addition, UPLC-MS analysis showed a greater variety of antioxidant components, such as olivil and osmanthuside H, in O. fragrans flower extract obtained by MA-DESE than by the traditional ethanol reflux method. These results demonstrated that MA-DESE, which is safe and eco-friendly, could substitute for the conventional solvent extraction process, which is time-consuming and tedious, for the extraction of antioxidant components from O. fragrans flower.

桂花（Lour）花是东方国家的一种典型的芳香草药，含有多种生物活性化合物，其提取物已广泛用作食品和化妆品中的天然抗氧化剂。然而，现有的提取方法在提取过程中使用有机溶剂，这是非生态友好的并且对人体健康有害。在这项研究中，我们首次向我们介绍了微波辅助的深共熔溶剂萃取（MA-DESE），以从香豆中提取抗氧化剂成分。花。通过使用响应面方法，对MA-DESE程序进行了优化，验证并与传统溶剂提取方法进行了比较。在以下最佳MA-DESE参数下，达到101.81 mg Trolox当量/ g干重的最大抗氧化活性：微波功率，497.12 W；微波处理时间59.03 s；固液比为31.14 mL / g。此外，UPLC-MS分析显示更多种类的抗氧化成分，如olivil和osmanthuside H的，在桂花通过MA-DESE获得的花提取物比通过传统乙醇回流法获得的花提取物。这些结果表明，MA-DESE是一种安全，环保的产品，可替代费时且繁琐的常规溶剂提取工艺，以从苦参中提取抗氧化剂成分。