RESUMEN
In this study, we report the metabolic profiling of several previously uncharacterized Passiflora species native to Brazil, employing molecular networks to delve deeper into chemical constituents. Using the GNPS platform, in silico tools, and substructure annotation techniques, we expanded the chemical annotations. Principal Coordinate Analysis (PCoA) revealed significant metabolic similarities between several species, including P. incarnata, suggesting shared pharmacological potential. Our identification of metabolic compounds facilitated comparisons between understudied species with medicinal properties. Notably, we documented 25 previously uncharacterized species, paving the way for the development of novel products aimed at improving human well-being. This research focused on several native Passiflora species from Brazil, highlighting their unexplored therapeutic potential.
RESUMEN
RATIONALE: Anthrone and oxanthrone are important anthraquinone derivatives present in medicinal plants which are used in therapeutics as laxatives. Some of these plants need to be stored at least one year before they can be used in order to oxidize anthrones into oxanthrones, so to avoid severe diarrhea and dehydration. Therefore, this work aimed to characterize fragmentation reactions between these anthraquinones to provide an easy way to differentiate between the two classes, since it is necessary and important to discriminate and identify these derivatives in laxative plants and phytotherapic drugs. METHODS: Anthrone (cascarosides A-D) and oxanthrone (10-hydroxycascaroside A and B) derivatives were isolated and identified by NMR (1 H, 13 C, DEPT, NOESY) and used for fragmentation study by direct infusion on an electrospray ionization (ESI) ion trap mass spectrometer (AmazonSL, Bruker) in positive and negative mode. RESULTS: The additional hydroxyl at C-10 in oxanthrones allowed McLafferty-type rearrangements to form the quinone group in positive mode, while in negative mode the second sugar loss infringed the odd-electron rule and formed a radical fragment. No differences in fragmentation reactions were found between diastereoisomeric pairs, although the additional oxygen at C-10 of oxanthrones allowed a different fragmentation pattern. CONCLUSIONS: The proposed fragmentation patterns can be used to differentiate anthrones from oxanthrones in both ion modes. In addition, they can be applied to differentiate these compounds in anthraquinone-rich plants and phytotherapic drugs. Finally, herein, the strategy applied allowed us to identify new natural products. Copyright © 2017 John Wiley & Sons, Ltd.