Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, PB, 58051-900, Brazil.
Phytochem Anal. 2021 Nov;32(6):1011-1026. doi: 10.1002/pca.3043. Epub 2021 Mar 18.
Given the diversity of secondary metabolites produced by species of the genus Erythroxylum, in addition to the many methods that have already been described in the literature, modern screening and identification methodologies, such as dereplication, represent an efficient and quick strategy compared to the classic techniques linked to natural product research.
The objective of the present study was to determine the phenolic profiles obtained from three species of Erythroxylum (Erythroxylum pauferrense Plowman, Erythroxylum pulchrum A.St.-Hil. and Erythroxylum simonis Plowman) by dereplication using liquid chromatography coupled with ESI-MS and HRESIMS.
Ethyl acetate and n-butanolic fractions from crude ethanolic extract of Erythroxylum species were analyzed by HPLC-ESI-MS and HPLC-HRESIMS, in order to identify its corresponding compounds. Experiments were performed in negative ionization mode, and the metabolites were provisionally identified based on deprotonated molecules, molecular formulas, fragmentation patterns and literature data. The corresponding isolated compounds were characterized by H and C NMR spectroscopy.
According to the dereplication method, it was possible to establish and compare the phenolic profile of the corresponding species by the assignment of 55 compounds, most of which were first described in these species and among which some were also new to the Erytroxylum genus. Additionally, nine compounds were isolated, including biphenyl-3,3',4,4'-tetraol, where the mass spectral data were not sufficient for their identification, and reported for the first time in the Erythroxylaceae family.
This research contributes to the phytochemical knowledge of the Erythroxylum genus and demonstrates the importance of the dereplication method regarding the investigation of natural products, enabling accurate identification of the metabolites while avoiding the efforts and material expenses involved in the isolation of known compounds.
鉴于该属的物种产生的次生代谢产物的多样性，除了文献中已经描述的许多方法外，现代筛选和鉴定方法，如去重复，与天然产物研究相关的经典技术相比，代表了一种高效、快速的策略。
本研究的目的是通过使用液质联用和高分辨电喷雾质谱对三种 Erythroxylum 物种（Erythroxylum pauferrense Plowman、Erythroxylum pulchrum A.St.-Hil. 和 Erythroxylum simonis Plowman）的粗乙醇提取物的乙酸乙酯和正丁醇馏分进行分析，以确定通过去重复得到的酚类图谱。
采用 HPLC-ESI-MS 和 HPLC-HRESIMS 分析 Erythroxylum 物种的乙酸乙酯和正丁醇馏分，以鉴定其相应的化合物。实验在负离子模式下进行，根据去质子分子、分子式、裂解模式和文献数据对代谢物进行临时鉴定。相应的分离化合物通过 1 H 和 13 C NMR 光谱进行表征。
根据去重复方法，可以通过分配 55 种化合物来建立和比较相应物种的酚类图谱，其中大多数化合物是首次在这些物种中描述的，其中一些化合物也是 Erytroxylum 属的新化合物。此外，还分离出了 9 种化合物，包括联苯-3,3',4,4'-四醇，其中质谱数据不足以对其进行鉴定，并首次报道于 Erythroxylaceae 科。
本研究有助于 Erythroxylum 属的植物化学知识，并证明了去重复方法在天然产物研究中的重要性，它可以准确鉴定代谢物，同时避免了分离已知化合物所涉及的努力和材料费用。
