Buche Gaëlle, Colas Cyril, Fougère Laëtitia, Destandau Emilie
Institut de Chimie Organique et Analytique, Université d'Orléans-CNRS, UMR 7311 BP 6759, CEDEX 2, 45067 Orléans, France.
Centre de Biophysique Moléculaire, CNRS-Université d'Orléans, UPR 4301, CEDEX 2, 45071 Orléans, France.
Metabolites. 2021 Oct 6;11(10):684. doi: 10.3390/metabo11100684.
Two species of oak are dominant in French forests: pedunculate oak () and sessile oak (.). Their differentiation is not straightforward but is essential to better understand their respective molecular content in order to better valorize them. Thus, to improve oak species identification, an untargeted UHPLC-HRMS/MS method associated with a two-step data treatment was developed to analyze a wide range of specialized metabolites enabling the comparison of both species of oak extracts. Pooled extracts from sessile and pedunculate oaks, composed of extracts from several trees of pure species from various origins, were compared using first the Venn diagram, as a quick way to get an initial idea of how close the extracts are, and then using a molecular network to visualize, on the one hand, the ions shared between the two species and, on the other hand, the compounds specific to one species. The molecular network showed that the two species shared common clusters mainly representative of tannins derivatives and that each species has specific molecules with similar fragmentation patterns, associated in specific clusters. This methodology was then applied to compare these two pooled extracts to unknown individuals in order to determine the species. The Venn diagram allowed for the quick presumption of the species of the individual and then the species could be assigned more precisely with the molecular network, at the level of specific clusters. This method, developed for the first time, has several interests. First, it makes it possible to discriminate the species and to correctly assign the species of unknown samples. Moreover, it gave an overview of the metabolite composition of each sample to better target oak tree utilization and valorization.
有柄橡树（）和无柄橡树（）。它们的区分并非一目了然，但对于更好地了解它们各自的分子成分以便更好地利用它们至关重要。因此，为了改进橡树品种的鉴定，开发了一种与两步数据处理相关联的非靶向超高效液相色谱-高分辨质谱/质谱方法，用于分析多种特殊代谢产物，从而能够比较两种橡树提取物。使用来自不同产地的多个纯品种树木的提取物组成的无柄橡树和有柄橡树的混合提取物，首先使用维恩图进行比较，作为快速了解提取物相似度的一种方法，然后使用分子网络一方面可视化两种橡树之间共享的离子，另一方面可视化特定于某一品种的化合物。分子网络显示，这两个品种共享主要代表单宁衍生物的共同聚类，并且每个品种都有具有相似碎片化模式的特定分子，这些分子聚集在特定的聚类中。然后将该方法应用于将这两种混合提取物与未知个体进行比较，以确定品种。维恩图可以快速推测个体的品种，然后通过分子网络在特定聚类水平上更精确地确定品种。首次开发的这种方法有几个优点。首先，它能够区分品种并正确确定未知样品的品种。此外，它还概述了每个样品的代谢产物组成，以便更好地确定橡树的利用和价值。
