Profiling and identification of chlorogenic acid metabolites in rats by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer

<p>1. Chlorogenic acids (CGAs), one kind of major bioactive constituents isolated from <i>Flos Lonicera Japonica</i>, possess many biological activities, such as antibacterial, antioxidant and antiviral activities. In this study, we established an efficient strategy using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) to profile the <i>in vivo</i> metabolic fate of CGAs in rat urine and plasma.</p> <p>2. The extract from <i>Flos Lonicera Japonica</i> was orally administrated to Sprague-Dawley (SD) rats at a dose of 1000 mg/kg body weight. Then, a combination of various post-acquisition data mining methods, including high-resolution extracted ion chromatogram (HREIC) and multiple mass defect filters (MMDFs) and diagnostic product ions (DPIs), were adopted to characterize the known and unknown CGA metabolites in SD rats.</p> <p>3. As a result, a total of 68 CGA metabolites were unambiguously or tentatively screened and characterized. These metabolites, including 18 prototype compounds and 50 metabolites, were deduced to be yielded <i>via</i> methylation, hydrogenation, demethylation, dehydration, sulfate conjugation, glucuronide conjugation, glycosylation conjugation and their composite reactions, which mainly occurred to caffeoylquinic acids, dicaffeoylquinic acids, <i>p</i>-coumaroylquinic acids and feruloylquinic acids.</p> <p>4. In conclusion, this study profiled CGA metabolites, which are useful in understanding the <i>in vivo</i> metabolic fate, effective forms, and pharmacological and toxic actions of CGAs.</p