College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China.
Hunan Engineering Technology Research Center for Rapeseed Oil Nutrition Health and Deep Development, Changsha 410128, China.
Molecules. 2023 Jul 20;28(14):5538. doi: 10.3390/molecules28145538.
Taking the extraction yield of polysaccharide (BSP) as the index and taking the type of deep eutectic solvents (DESs), extraction time, extraction temperature, DES water content, and solid-liquid ratio as the investigation factors, single-factor and Box-Behnken response surface tests were carried out to optimize the extraction process of BSP. Thus, the antioxidant activity of BSP on DPPH radicals, ABTS radicals and ferric reducing antioxidant power were determined. The results showed that the most suitable deep eutectic solvent was DES-2, namely choline chloride-urea. The optimal extraction conditions for BSP were an extraction time of 47 min, extraction temperature of 78 °C, water content of 35%, and solid-liquid ratio of 1:25. Under this optimized condition, the extraction yield of BSP was able to reach (558.90 ± 8.83) mg/g, and recycling studies indicated the good cycle stability of the DES. Antioxidant results showed that BSP had superior antioxidant activity and had a dose-response relationship with drug concentration. Compared with polysaccharide obtained via conventional hot water extraction (BSP-W), the extraction yield of BSP obtained through this method (BSP-2) increased by 36.77%, the scavenging activity of DPPH radicals increased by 24.99%, the scavenging activity of ABTS radicals increased by 41.16%, and the ferric reducing antioxidant power increased by 49.19%. Therefore, DESs as new green reagents and BSP extracted with DESs not only had a high yield but also had strong antioxidant activity.
以多糖（BSP）的提取率为指标，以深共晶溶剂（DESs）的类型、提取时间、提取温度、DES 含水量和固液比为考察因素，进行单因素和 Box-Behnken 响应面试验，优化 BSP 的提取工艺。进而测定 BSP 对 DPPH 自由基、ABTS 自由基和铁还原抗氧化能力的抗氧化活性。结果表明，最适合的深共晶溶剂是 DES-2，即氯化胆碱-尿素。BSP 的最佳提取条件为提取时间 47 min、提取温度 78℃、含水量 35%、固液比 1:25。在优化条件下，BSP 的提取率可达（558.90±8.83）mg/g，且 DES 具有良好的循环稳定性。抗氧化结果表明，BSP 具有优越的抗氧化活性，且与药物浓度呈剂量反应关系。与传统热水提取的多糖（BSP-W）相比，该方法提取的多糖（BSP-2）的提取率提高了 36.77%，对 DPPH 自由基的清除活性提高了 24.99%，对 ABTS 自由基的清除活性提高了 41.16%，铁还原抗氧化能力提高了 49.19%。因此，DES 作为新型绿色试剂，以及用 DES 提取的 BSP 不仅产率高，而且具有较强的抗氧化活性。
