Extracts from spruce bark obtained using different deep eutectic solvents were screened for their total phenolic content (TPC) and antioxidant activities. Water containing choline chloride-based deep eutectic solvents (DESs) with lactic acid and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol, with different molar ratios, were used as extractants. Basic characteristics of the DESs (density, viscosity, conductivity, and refractive index) were determined. All the DESs used behave as Newtonian liquids. The extractions were performed for 2 h at 60 °C under continuous stirring. TPC was determined spectrophotometrically, using the Folin-Ciocalteu reagent, and expressed as gallic acid equivalent (GAE). The antioxidant activity was determined spectrophotometrically by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The TPC varied from 233.6 to 596.2 mg GAE/100 g dry bark; radical scavenging activity (RSA) ranged between 81.4% and 95%. This study demonstrated that deep eutectic solvents are suitable solvents for extracting phenolic compounds from spruce bark.

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深共熔溶剂分离的云杉皮提取物总酚含量和抗氧化活性的研究

筛选使用不同的深共熔溶剂获得的云杉皮提取物的总酚含量（TPC）和抗氧化活性。含有乳酸和1,3-丙二醇，1,3-丁二醇，1,4-丁二醇和1,5-戊二醇的含有氯化胆碱的低共熔溶剂（DESs）用作萃取剂。确定了DES的基本特性（密度，粘度，电导率和折射率）。所使用的所有DES均表现为牛顿液体。在连续搅拌下于60℃进行萃取2小时。使用Folin-Ciocalteu试剂通过分光光度法确定TPC，并表示为没食子酸当量（GAE）。抗氧化剂活性通过2，2-二苯基-1-吡啶并肼基（DPPH）自由基清除法分光光度法测定。TPC从233.6到596.2 mg GAE / 100 g干树皮不等; 自由基清除活性（RSA）介于81.4％和95％之间。这项研究表明，深共晶溶剂是从云杉树皮中提取酚类化合物的合适溶剂。