A fast and efficient selective pressurized liquid extraction (sPLE) method was developed to extract secondary metabolites from complex plant matrix. Convallaria majalis L., a plant producing toxic steroids, was used as proof-of-concept. The method was optimized in the aspects of preheating, dispersant, extraction temperature and solvent, and the use of C18 as in-cell cleanup sorbent. Eight authentic natural steroids with diverse sugar moieties and hydrophobicities were selected as reference analytes and spiked to 0.1 g dried leaves. The extraction performance was evaluated based on the analytes’ stability, recovery, matrix effect in the electrospray interface and the level of co-extractives. With the optimal method, the extraction was finished in 10 min. A colorless extract was obtained with recoveries ranging from 63% to 107% and absolute matrix effects ranging from 3% to 27%. The optimized method was validated by extracting 0.1 g, 0.2 g and 0.4 g spiked plant samples; method accuracy and precision were assessed by recoveries and relative standard deviations of the combined extraction-analysis workflow. The method was also tested on soil samples and indicated its suitability for measuring secondary metabolites in multiple environmental matrices. To our knowledge, this is the first time sPLE has been reported to extract plant secondary metabolites from a complex plant matrix, with satisfactory recoveries and low matrix effects. This is also the first time (s)PLE has been reported to extract plant secondary metabolites from soil. We envision the method be coupled with liquid chromatography-electrospray ionization-high resolution mass spectrometry in a standard metabolomics workflow to facilitate plant metabolomics studies.

中文翻译：

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植物次生代谢产物选择性加压液体提取——以铃兰为例

开发了一种快速高效的选择性加压液体萃取（sPLE）方法，用于从复杂的植物基质中提取次生代谢物。铃兰（Convallaria majalis L.）是一种产生有毒类固醇的植物，被用作概念验证。该方法在预热、分散剂、萃取温度和溶剂以及使用C18作为细胞内净化吸附剂等方面进行了优化。选择八种具有不同糖部分和疏水性的真实天然类固醇作为参考分析物，并添加到 0.1 g 干叶中。根据分析物的稳定性、回收率、电喷雾界面的基质效应和共萃取物的水平评估萃取性能。采用最佳方法，提取时间为10 min。获得无色提取物，回收率范围为 63% 至 107%，绝对基质效应范围为 3% 至 27%。通过提取0.1 g、0.2 g、0.4 g加标植物样品对优化方法进行验证；通过提取-分析组合工作流程的回收率和相对标准偏差来评估方法的准确性和精密度。该方法还在土壤样品上进行了测试，表明其适用于测量多种环境基质中的次生代谢物。据我们所知，这是首次报道 sPLE 从复杂的植物基质中提取植物次生代谢物，具有令人满意的回收率和较低的基质效应。这也是首次报道(s)PLE从土壤中提取植物次生代谢产物。我们设想该方法与标准代谢组学工作流程中的液相色谱-电喷雾电离-高分辨率质谱联用，以促进植物代谢组学研究。