Metabolic Stability and Metabolite Characterization of Capilliposide B and Capilliposide C by LC⁻QTRAP⁻MS/MS

Pharmacokinetics, oral bioavailability and metabolic analysis of solasodine in mice by dried blood spot LC-MS/MS and UHPLC-Q-Exactive MS

Solasodine, a major ingredient in Solanaceae family, has various biological functions such as inducing neurogenesis, anticonvulsant and anti-tumor. Its risk assessment has also drawn public attention. However, little is known about its oral bioavailability and metabolic process. In this study, an liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of solasodine in mice dried blood spot (DBS) samples. To block nonspecific adsorption, DBS samples were pretreated with bovine serum albumin (BSA) and then extracted with ethyl acetate. This method was applied to a pharmacokinetic and bioavailability study of solasodine. The absolute bioavailability was only 1.28%. Thereafter, its metabolites in mice were characterized using an ultra-performance liquid chromatography Q-Exactive high-resolution mass spectrometer (UHPLC-QE-HRMS). Several isomeric metabolites were well separated and differentiated using their retention time, fragmentation pathways and correspondingly fragmentation rules of solasodine. As a result, 21 metabolites were characterized including 16 phase I and 5 phase II metabolites. The proposed metabolic pathways showed that solasodine mainly experienced oxidation, dehydration, dehydrogenation and sulfation. These results could help us to better understand the efficacy and safety of solasodine.

A target-group-change couple with mass defect filtering strategy to identify the metabolites of "Dogel ebs" in rats plasma, urine and bile

"Dogel ebs" was known as Sophora flavescens Ait., a classical traditional Chinese Mongolian herbal medicine, which had the effects on damp-heat dysentery, scrofula, and syndrome of accumulated dampness toxicity. Although the chemical constituents have been clarified by our previous studies, the metabolic transformation of "Dogel ebs" in vivo was still unclear. To explore the mechanism of "Dogel ebs," the metabolites in plasma, bile, and urine samples were investigated. A fast positive and negative ion switching technology was used for the simultaneous determination of flavonoids and alkaloids in "Dogel ebs" in a single run. And a target-group-change coupled with mass defect filtering strategy was utilized to analyze the collected data. 89 parent compounds and 82 metabolites were characterized by high-performance liquid chromatography with quadrupole exactive Orbitrap mass spectrometry. Both phase I and phase II metabolites were observed and the metabolic pathways involved in oxidation, demethylation, acetylation, and glucuronidation. 69 metabolites of "Dogel ebs," including three hydroxyls bonding xanthohumol, formononetin-7-O-glucuronide, 2'-hydroxyl-isoxanthohumol decarboxylation metabolite, oxysophocarpine dehydrogen, 9α-hydroxysophoramine-O-glucuronide, etc. were reported for the first time.

In Vitro and In Situ Characterization of the Intestinal Absorption of Capilliposide B and Capilliposide C from Lysimachia capillipes Hemsl

The goal of this investigation was to determine the processes and mechanism of intestinal absorption for capilliposide B (CAPB) and capilliposide C (CAPC) from the Chinese herb, Lysimachia capillipes Hemsl. An analysis of basic parameters, such as drug concentrations, time, and behavior in different intestinal segments was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS). The susceptibility of CAPB and CAPC to various inhibitors such as P-glycoprotein (P-gp) inhibitor (verapamil); multidrug resistance-associated protein 2 (MRP2) inhibitor (indomethacin); cytochrome P450 protein 3A4 (CYP3A4) inhibitor (ketoconazole); and the co-inhibitor of P-gp, MRP2 and CYP3A4 (cyclosporine A) were assessed using both caco-2 cell monolayer and single-pass intestinal perfusion (SPIP) models. As a result, CAPB and CAPC are both poorly absorbed in the intestines and exhibited segment-dependent permeability. The intestinal permeability of CAPB and CAPC were significantly increased by the co-treatment of verapamil, indomethacin. In addition, the intestinal permeability of CAPB was also enhanced by ketoconazole and cyclosporine A. It can be concluded that the intestinal absorption mechanisms of CAPB and CAPC involve processes such as facilitated passive diffusion, efflux transporters, and enzyme-mediated metabolism. Both CAPB and CAPC are suggested to be substrates of P-gp and MRP2. However, CAPB may interact with the CYP3A4 system.