Dereplication of phenolic derivatives of three Erythroxylum species using liquid chromatography coupled with ESI-MSn and HRESIMS

Introduction 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. Objective 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-MSn and HRESIMS. Material and Methods Ethyl acetate and n-butanolic fractions from crude ethanolic extract of Erythroxylum species were analyzed by HPLC-ESI-MSn 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-1 and C-13 NMR spectroscopy. Results 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. Conclusion 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.

Automated summary

The study successfully identified the compound composition of three species from the Erythroxylum genus using the dereplication method, revealing 55 compounds, most of which were first described in these species and some were new to the genus. Additionally, nine compounds were isolated, including one that was reported for the first time in the Erythroxylaceae family. This research highlights the importance of dereplication in natural product investigations for accurate compound identification and cost-saving in compound isolation.