Ultrasound-assisted extraction and antioxidant activity of triterpenoid saponins from Platycodon grandiflorum roots: Optimization, purification, and molecular insights

作者：Wei Li, Yanqing Zhang, Yinghao Wei, Jie Sun, Xiaotong Zhao, Junbo Xie · 发表于：Industrial Crops and Products · 年份：2024 · DOI：10.1016/j.indcrop.2024.119877 · 被引用次数：27 · 研究领域：Natural product bioactivities and synthesis、Antioxidant Activity and Oxidative Stress、Phytochemicals and Antioxidant Activities

Platycodon grandiflorum roots (PGR) is a medicinal plant rich in triterpenoid saponins, which are known for their antioxidant properties. In this study, ultrasonic-assisted extraction (UAE) was employed to extract total saponins from PGR, with the extraction process optimized through single-factor experiments and response surface methodology (RSM). The optimal extraction conditions were determined to be an extraction time of 51.04 min, ultrasonic power of 153.79 W, and a temperature of 49.59°C, resulting in a saponins yield of 4.83 %. Purified using n-butanol extraction followed by ethanol elution produced four distinct fractions, with the PAE-3 fraction containing the highest saponins concentration, primarily composed of Platycodin G1 and Platycodin E. In vitro antioxidant assays revealed that PAE-3 exhibited the strongest radical scavenging capacity and reducing power. A strong negative correlation between the content of Platycodin G1 and Platycodin E and IC 50 values in antioxidant assays suggests that these compounds are key contributors to the antioxidant activity of PAE-3. In vivo studies using Caenorhabditis elegans further validated the antioxidant potential of PAE-3, showing a significant reduction in reactive oxygen species levels and enhanced activity of superoxide dismutase (SOD) and glutathione (GSH). UPLC-Q-TOF/MS analysis identified the structure of Platycodin G1 and Platycodin E, while molecular docking revealed strong binding affinities of these compounds to ...