Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4a (Collegium Pharmaceuticum), 20-093 Lublin, Poland.
Faculty of Medicine, Medical University of Lublin, Aleje Racławickie 1, 20-059 Lublin, Poland.
Molecules. 2020 Dec 18;25(24):6005. doi: 10.3390/molecules25246005.
The 2,2-diphenyl-1-picrylhydrazyl (DPPH)-reverse phase (RP)-HPLC-diode array detector (DAD) method was tested on standard antioxidants (AOs), i.e., reduced glutathione (GSH), ascorbic acid (vitamin C), and alcoholic extracts of L. An elaborated HPLC procedure enabled the simultaneous measurement of the redox couple DPPH-R (2,2-diphenyl-1-picrylhydrazyl radical)/DPPH-H (2,2-diphenyl-1-picrylhydrazine). Both forms were fully separated (R = 2.30, = 1.65) on a Zorbax Eclipse XDB-C18 column eluted with methanol-water (80:20, /) and detected at different wavelengths in the range of 200-600 nm. The absorbance increases of the DPPH-H as well as the DPPH-R peak inhibition were measured at different wavelengths in visible and UV ranges. The chromatographic method was optimized, according to reaction time (slow, fast kinetics), the linearity range of DPPH radical depending on the detection conditions as well as the kind of the investigated antioxidants (reference chemicals and the ground elder prepared from fresh and dry plants). The scavenging capacity was expressed by the use of percentage of peak inhibition and the IC parameters. The evaluated extracts displayed antioxidant activity, higher than 20% inhibition against 350 µM DPPH free radical. The results show that extract prepared from dry plants in the ultrasonic bath exhibits the highest antioxidant potential (IC = 64.74 ± 0.22 µL/mL).
2,2-二苯基-1-苦基肼基（DPPH）-反相（RP）-高效液相色谱-二极管阵列检测器（DAD）方法在标准抗氧化剂（AOs）上进行了测试，即还原型谷胱甘肽（GSH）、抗坏血酸（维生素 C）和柳属植物的醇提物。经过详细的 HPLC 程序，可以同时测量氧化还原偶联物 DPPH-R（2,2-二苯基-1-苦基肼基自由基）/DPPH-H（2,2-二苯基-1-苦基肼）。在 Zorbax Eclipse XDB-C18 柱上，甲醇-水（80:20，/）作为洗脱液，在 200-600nm 的波长范围内进行检测，两种形式都能完全分离（R = 2.30， = 1.65）。在可见和紫外范围内，不同波长下测量 DPPH-H 的吸光度增加以及 DPPH-R 峰抑制。根据反应时间（缓慢、快速动力学）、DPPH 自由基的线性范围以及所研究的抗氧化剂的种类（参考化学品和从新鲜和干燥植物制备的 Ground Elder）优化了色谱方法。通过使用峰抑制百分比和 IC 参数来表示清除能力。评价提取物显示出抗氧化活性，对 350µM DPPH 自由基的抑制率高于 20%。结果表明，在超声浴中用干植物制备的提取物表现出最高的抗氧化潜力（IC = 64.74 ± 0.22µL/mL）。
