Fast profiling of the integral metabolism of flavonols in the active fraction of Gossypium herbaceam L. using liquid chromatography/multi-stage tandem mass spectrometry.

A method of fast profiling the constituents in an active herbal extract and their metabolites in biological fluids based on the combination of fragmentation behavior and metabolic pathways is described. The complementary information from fragmentation behavior and metabolic pathways helped not only to identify the structure of parent constituents and metabolites, but also to correlate metabolites back to their parent forms. An active fraction obtained from Gossypium herbaceam L., named AB-8-2, and bile samples from rats administered it orally and intravenously were analyzed using high-performance liquid chromatography/multi-stage tandem mass spectrometry (HPLC-MSn) in a single chromatographic run. Fifty-eight flavonols comprising mixed sulfate, methyl, glucuronide and glycoside derivatives of quercetin or kaempferol were detected, including several groups of isomers. By contrasting the analytical results from AB-8-2 and from bile samples derived from different administration routes, a profile of the biotransformation of the flavonols in AB-8-2 was obtained. The results should be of benefit in targeting potential active ingredients in complex mixtures, such as herbs or their active extracts. Copyright (c) 2007 John Wiley & Sons, Ltd.