Department of Tea Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Molecules. 2019 Oct 22;24(20):3794. doi: 10.3390/molecules24203794.
Saponins in the seeds have a broad spectrum of biological properties and application potentials. However, up to now, no chromatographic methods have been developed to provide full fingerprinting and quality assurance for these saponins. This research aimed to develop a novel method to tentatively identify and quantify saponins in seeds by ultra-high-performance liquid chromatography coupled with photo-diode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS), and compare it with the classic vanillin-sulfuric acid assay. Fifty-one triterpene saponins, including six potentially new compounds, were simultaneously detected by UPLC-PDA-MS/MS, and their chemical structures were speculated according to the retention behavior and fragmentation pattern. The total saponin content in the crude extract and the purified saponin fraction of seeds were quantified to be 19.57 ± 0.05% (wt %) and 41.68 ± 0.09% (wt %) respectively by UPLC-PDA at 210 nm, while the corresponding values were determined to be 43.11 ± 3.17% (wt %) and 56.60 ± 5.79% (wt %) respectively by the vanillin-sulfuric acid assay. The developed UPLC-PDA -MS/MS method could determine specified saponins, and is more reliable for quantifying the seed saponins than the classic spectrophotometric method. It is of great significance for the future investigations and applications of these saponins.
种子中的皂苷具有广泛的生物活性和应用潜力。然而，迄今为止，尚未开发出色谱方法来为这些皂苷提供全面的指纹图谱和质量保证。本研究旨在开发一种新的方法，通过超高效液相色谱-光电二极管阵列检测器-四极杆飞行时间质谱（UPLC-PDA-QTOF-MS/MS）对种子中的皂苷进行定性和定量分析，并与经典香草醛-硫酸比色法进行比较。通过 UPLC-PDA-MS/MS 同时检测到五十一种三萜皂苷，包括六种潜在的新化合物，根据保留行为和裂解模式推测其化学结构。通过 UPLC-PDA 在 210nm 处测定种子粗提取物和纯化皂苷级分中的总皂苷含量分别为 19.57±0.05%（wt%）和 41.68±0.09%（wt%），而香草醛-硫酸比色法测定的相应值分别为 43.11±3.17%（wt%）和 56.60±5.79%（wt%）。开发的 UPLC-PDA-MS/MS 方法可以测定特定的皂苷，并且比经典分光光度法更可靠地定量种子皂苷。这对于这些皂苷的未来研究和应用具有重要意义。
