Polydopamine-Coated Magnetic Molecularly Imprinted Polymers with Fragment Template for Identification of <i>Pulsatilla</i> Saponin Metabolites in Rat Feces with UPLC-Q-TOF-MS

In this work, a modified pretreatment method using magnetic molecularly imprinted polymers (MMIPs) was successfully applied to study the metabolites of an important botanical with ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The MMIPs for glucoside-specific adsorption was used to identify metabolites of <i>Pulsatilla chinensis</i> in rat feces. Polymers were prepared by using Fe₃O₄ nanoparticles as the supporting matrix, d-glucose as fragment template, and dopamine as the functional monomer and cross-linker. Results showed that MMIPs exhibited excellent extraction performance, large adsorption capacity (5.65 mg/g), fast kinetics (60 min), and magnetic separation. Furthermore, the MMIPs coupled with UPLC-Q-TOF-MS were successfully utilized for the identification of 17 compounds including 15 metabolites from the <i>Pulsatilla</i> saponin metabolic pool. This study provides a reliable protocol for the separation and identification of saponin metabolites in a complex biological sample, including those from herbal medicines

6,8-di-<i>C</i>-glycosyl flavones with <i>β</i>-furanoarabinose from <i>Scutellaria baicalensis</i> and their anti-inflammatory activities

<p>Two flavone di-<i>C</i>-glycosides, a pair of isomers, were isolated from <i>Scutellaria baicalensis</i>. The structures of compounds <b>1</b> and <b>2</b> were elucidated by means of physical data, including 1D and 2D NMR and HR-ESI-MS. Supporting theoretical calculations of the compound conformational landscape has also been conducted for geometry optimization. This is the first report of the natural occurrence of <i>β</i>-furanoarabinoside. In addition, the effects of compounds <b>1</b> and <b>2</b> on NO, pro-inflammatory cytokines, PGE2 and COX-2 levels were measured in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. The pair of isomers exhibited significant inhibitory effects on inflammation.</p