School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China.
School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China; Guangdong Provincial Public Laboratory of Analysis and Testing Technology, China National Analytical Center, Guangzhou 510070, China.
Ultrason Sonochem. 2020 Sep;66:105073. doi: 10.1016/j.ultsonch.2020.105073. Epub 2020 Mar 27.
A green method for simultaneous extraction and enrichment of flavonoids from Euonymus alatus was developed by ultrasonic-assisted extraction (UAE) and temperature-induced cloud point extraction (TICPE) using PEG-base aqueous solution as the extractant. Based on screening different molecular weights of PEGs, PEG-400/water was used as the extractant, and the effects of key factors on extraction yields of flavonoids were investigated by single-factor experiments and response surface methodology (RSM). The optimum conditions of UAE were as follows: PEG-400 concentration of 16% (w/w), particle size of 80 mesh, solvent-to-material ratio of 60:1, extraction temperature of 90 °C and extraction time of 15 min. The results obtained by validation experiments were consistent with the values predicted by RSM. Temperature-induced formation of the aqueous two-phase system (ATPS) and TICPE process were further investigated by controlling temperature and adding (NH)SO. In the presence of (NH)SO, the ATPS formed at 75 ℃ and pH 3.5 could effectively improve separation and recovery of flavonoids with enrichment factor of above five times. Gallic acid, catechin, dihydromyricetin and ellagic acid in the extract were identified and confirmed by UPLC-Q-TOF-MS and the corresponding standards. The UAE-TICPE coupled to HPLC was successfully applied for extraction and determination of flavonoids in two batches of Euonymus alatus. The extraction yields of catechin, dihydromyricetin and total flavonoids were 0.377-0.684 mg/g, 1.091-1.353 mg/g and 2.612-3.146 mg/g, respectively. Compared to conventional extraction methods, PEG-based UAE integrated with TICPE in one-step procedure exhibited higher extraction efficiency and better extraction selectivity.
一种从卫矛中同时提取和富集类黄酮的绿色方法，通过超声辅助提取（UAE）和温度诱导浊点萃取（TICPE），使用 PEG 基水溶液作为萃取剂。基于筛选不同分子量的 PEG，选择 PEG-400/水作为萃取剂，通过单因素实验和响应面法（RSM）研究了关键因素对类黄酮提取率的影响。UAE 的最佳条件如下：PEG-400 浓度为 16%（w/w），粒径为 80 目，溶剂与物料比为 60:1，提取温度为 90°C，提取时间为 15min。验证实验的结果与 RSM 预测值一致。通过控制温度和添加（NH4）2SO4，进一步研究了温度诱导形成的双水相体系（ATPS）和 TICPE 过程。在（NH4）2SO4的存在下，在 75°C 和 pH 3.5 形成的 ATPS 可以有效地提高类黄酮的分离和回收，富集因子超过五倍。通过 UPLC-Q-TOF-MS 和相应的标准品，鉴定并确证了提取物中的没食子酸、儿茶素、二氢杨梅素和鞣花酸。将 UAE-TICPE 与 HPLC 耦合成功应用于两批卫矛中类黄酮的提取和测定。儿茶素、二氢杨梅素和总黄酮的提取率分别为 0.377-0.684mg/g、1.091-1.353mg/g 和 2.612-3.146mg/g。与传统提取方法相比，PEG 基 UAE 与 TICPE 一步集成法具有更高的提取效率和更好的提取选择性。
