New cascarosides from Rhamnus purshiana and fragmentation studies of the class by ion trap mass spectrometry
| Autor: | Norberto Peporine Lopes, Denise Brentan Silva, Gibson Gomes de Oliveira, Danielle R. Pinho, Daniel R. Callejon, Daniel P. Demarque, Carlos Alexandre Carollo |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
biology Electrospray ionization 010401 analytical chemistry Organic Chemistry DEPT biology.organism_classification 01 natural sciences Anthrone Anthraquinone 0104 chemical sciences Analytical Chemistry 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology chemistry Fragmentation (mass spectrometry) Anthraquinones Rhamnus purshiana Organic chemistry Ion trap Spectroscopy |
| Zdroj: | Rapid Communications in Mass Spectrometry. 31:1169-1174 |
| ISSN: | 0951-4198 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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