Selective and Sensitive Platform for Function-Based Screening of Potentially Harmful Furans

摘要

Many furan-containing compounds have been reported to be toxic and/or carcinogenic. Furanoids have been found in a wide range of fruits, herbs, foods, and beverages. The risks for intake of toxic furans have been rising, due to the rapid growth of globe-wide consumption of natural products. The objective of the study was to develop an analytical platform to screen cis-enediones (cis-enedials or γ-ketoenals) resulting from metabolic activation of potentially harmful furans. 2,5-Dimethylfuran (DMF), a model furan compound, was incubated with rat liver microsomes supplemented with glutathione (GSH) and 4-bromobenzylamine (BBA) as trapping agents, to produce a GSH/BBA-derived pyrrole. The incubation mixture was monitored by acquiring neutral loss scan of 129 Da and precursor ion scans of m/z 272, 169, and 171 in polarity switch mode. Four individual chromatograms showed the respective peak with the same retention time. An additional six furan-containing compounds were tested by the same approach, and similar observation was obtained. The system also showed its extremely high sensitivity, and an estimate of the limit of detection for DMF bioactivated in rat liver microsomes was <100 fmol. We also applied inductively coupled plasma mass spectrometry (ICP-MS) to monitor the formation of the bromine-tagged pyrrole derivatives. Crude extracts obtained from traditional Chinese medicine Dioscorea bulbifera L., known to contain furanoditerpenoids, were analyzed by the approach. In conclusion, the platform has been proven selective, sensitive, effective, and reliable, and ICP MS allows us to estimate the resulting bromine-labeled pyrroles without authentic standards.