文摘
The elaboration of novel techniques for flavonoid intracellular tracing would elucidate the compounds'absorption and bioavailability and assist molecular and pharmacological approaches, as they arepromising candidates for drug development. This study exploited the properties of quercetin (3,3',4',5,7-pentahydroxyflavone), found in high concentrations in the majority of edible plants. Through the useof UV-vis spectroscopy, confocal microscopy, and HPLC-ESI-MS, native quercetin, at physiologicallyrelevant concentrations, was found to exhibit a specific fluorescence (488 nmex/500-540 nmem) uponinternalization. This fluorescence shift is due to a non-covalent binding to intracellular targets (probablyproteins) and compatible with the settings applied in confocal microscopy. This property provides avaluable, selective alternative technique for quercetin tracing in cellular systems, permitting thequantitative evaluation of its transit at pharmacologically relevant concentrations and the validationof a number of already described molecular functions.