Abstract：
BACKGROUND: Natural deep eutectic solvents (NADES) have emerged as interesting extractants to develop botanical ingredients. They are nontoxic and biodegradable, nonflammable, easy to prepare, and able to solubilize a wide range of molecules. However, NADES extracts remain difficult to analyze because the metabolites of interest stay highly diluted in the nonvolatile viscous NADES matrix.
OBJECTIVE: This study presents a robust analytical workflow for the chemical profiling of NADES extracts. It is applied to Hypericum perforatum aerial parts extracted with the neutral mixture fructose/glycerol/water (3/1/1, w/w/w), and compared to the chemical profiling of a classical dry methanol extract.
METHODS: Exploiting polarity differences between metabolites, the H. perforatum NADES extract was partitioned in a liquid-liquid solvent system to trap the hydrophilic NADES constituents in the lower phase. The upper phase, containing a diversity of secondary metabolites from H. perforatum, was fractionated by centrifugal partition chromatography. All fractions were chemically investigated using a 13 C NMR dereplication method which involves hierarchical clustering analysis of the whole NMR dataset, a natural metabolite database for metabolite identification, and 2D NMR analyses for validation. Liquid chromatography-mass spectrometry (LC-MS) analyses were also performed to complete the identification process.
RESULTS: A range of 21 metabolites were unambiguously identified, including glycosylated flavonols, lactones, catechins, phenolic acids, lipids, and simple sugars, and 15 additional minor extract constituents were annotated by LC-MS based on exact mass measurements.
CONCLUSIONS: The proposed identification process is rapid and nondestructive and provides good prospects to deeply characterize botanical extracts obtained in nonvolatile and viscous NADES systems.
OBJECTIVE: This study presents a robust analytical workflow for the chemical profiling of NADES extracts. It is applied to Hypericum perforatum aerial parts extracted with the neutral mixture fructose/glycerol/water (3/1/1, w/w/w), and compared to the chemical profiling of a classical dry methanol extract.
METHODS: Exploiting polarity differences between metabolites, the H. perforatum NADES extract was partitioned in a liquid-liquid solvent system to trap the hydrophilic NADES constituents in the lower phase. The upper phase, containing a diversity of secondary metabolites from H. perforatum, was fractionated by centrifugal partition chromatography. All fractions were chemically investigated using a 13 C NMR dereplication method which involves hierarchical clustering analysis of the whole NMR dataset, a natural metabolite database for metabolite identification, and 2D NMR analyses for validation. Liquid chromatography-mass spectrometry (LC-MS) analyses were also performed to complete the identification process.
RESULTS: A range of 21 metabolites were unambiguously identified, including glycosylated flavonols, lactones, catechins, phenolic acids, lipids, and simple sugars, and 15 additional minor extract constituents were annotated by LC-MS based on exact mass measurements.
CONCLUSIONS: The proposed identification process is rapid and nondestructive and provides good prospects to deeply characterize botanical extracts obtained in nonvolatile and viscous NADES systems.
摘要：
背景：天然深共熔溶剂（NADES）已成为开发植物成分的有趣提取剂。它们无毒且可生物降解，不易燃，容易准备,并且能够溶解多种分子。然而,NADES提取物仍然难以分析，因为感兴趣的代谢物在非挥发性粘性NADES基质中保持高度稀释。
目的：本研究为NADES提取物的化学谱分析提供了一个稳健的分析工作流程。应用于用中性混合物果糖/甘油/水（3/1/1，w/w/w）提取的贯叶连翘。并与经典的干甲醇提取物的化学轮廓进行了比较。
方法：利用代谢物之间的极性差异，将贯叶H.NADES提取物分配在液-液溶剂系统中，以将亲水性NADES成分捕获在较低相中。上层阶段，含有来自H.perforatum的多种次生代谢产物，通过离心分配色谱法进行分馏。使用13CNMR去复制方法对所有馏分进行化学研究，该方法涉及整个NMR数据集的分层聚类分析，用于代谢物鉴定的天然代谢物数据库，和2DNMR分析进行验证。还进行液相色谱-质谱(LC-MS)分析以完成鉴定过程。
结果：明确鉴定了21种代谢物，包括糖基化黄酮醇，内酯,儿茶素,酚酸，脂质，和简单的糖，和15个额外的次要提取物成分通过LC-MS基于精确的质量测量进行注释。
结论：所提出的鉴定过程是快速且无损的，并且为深入表征在非挥发性和粘性NADES系统中获得的植物提取物提供了良好的前景。
目的：本研究为NADES提取物的化学谱分析提供了一个稳健的分析工作流程。应用于用中性混合物果糖/甘油/水（3/1/1，w/w/w）提取的贯叶连翘。并与经典的干甲醇提取物的化学轮廓进行了比较。
方法：利用代谢物之间的极性差异，将贯叶H.NADES提取物分配在液-液溶剂系统中，以将亲水性NADES成分捕获在较低相中。上层阶段，含有来自H.perforatum的多种次生代谢产物，通过离心分配色谱法进行分馏。使用13CNMR去复制方法对所有馏分进行化学研究，该方法涉及整个NMR数据集的分层聚类分析，用于代谢物鉴定的天然代谢物数据库，和2DNMR分析进行验证。还进行液相色谱-质谱(LC-MS)分析以完成鉴定过程。
结果：明确鉴定了21种代谢物，包括糖基化黄酮醇，内酯,儿茶素,酚酸，脂质，和简单的糖，和15个额外的次要提取物成分通过LC-MS基于精确的质量测量进行注释。
结论：所提出的鉴定过程是快速且无损的，并且为深入表征在非挥发性和粘性NADES系统中获得的植物提取物提供了良好的前景。
