Biological analysis of constituents in Spatholobi Caulis by UFLC-MS/MS: Enhanced quantification and application to permeability properties study in Caco-2 cell monolayer model.

Major chemical constituents in medicinal materials are often used as the marker compounds of traditional Chinese medicine (TCM) for treating various diseases. For spatholobi caulis (SPC), it contains a variety of flavones, phenolic acid esters, and lignans which exert many pharmacological effects. However, the absorption and permeability properties of these constituents of SPC are still unclear and require further investigation. Different types and major compounds of SPC were chosen as representative constituents to study their absorption and transepithelial transport characteristics in the human intestinal epithelium-like Caco-2 cell monolayer model. 35 constituents of SPC were evaluated by using ultra fast liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UFLC-MS/MS) method, acetonitrile and water containing with 0.5 mM ammonium acetate were used as mobile phase, these analytes with good linear relationships (R2 was within 0.9967-0.9998), precision (CV values were less than 10.23 %, LLOQ was less than 13.69 %), accuracy (Mean of inter- and intra-day were within 85.02 %-111.61 % and 85.50-112.97 %, respectively) and stability (The mean was within 85.07 %-113.93 %), among which 16 analytes showed good permeability, 5 analytes were considered to be poorly permeable compounds, and the other 14 analytes were assigned for the moderately absorbed compounds in Caco-2 cell monolayer model. The further results showed that the absorption mechanism of 7 well absorbed compounds, 8-O-methylretusin (1), genistein (7), spasuberol B (16), naringenin (18), isoliquiritigenin (19), 4-hydroxy-3-methoxy cinnamic acid methyl ester (23) and (+)-epipinoresinol (31) in SPC was mainly passive diffusion, their bidirectional transport rate was correlated with the concentration and transport time. The chemical structures of these compounds could affect the permeability properties on the cell monolayer. This study demonstrated the utility of Caco-2 cell monolayer model for evaluating the absorption properties and initial mechanisms of compounds in SPC in vitro, and provided important basis for predicting oral bioavailability of SPC compounds.

Systematic analysis of the metabolites of Angelicae Pubescentis Radix by UPLC-Q-TOF-MS combined with metabonomics approaches after oral administration to rats.

Angelicae Pubescentis Radix (APR) is a typical Traditional Chinese Medicine (TCM) and has been widely used to treat rheumatism and headache diseases in China. This research aimed to illustrate the metabolites of APR in vivo to lay a foundation for the clinics application. A UPLC-Q-TOF-MS method combined with metabonomics approaches is used to address this objective. The separation was achieved on an Agilent SB-C18 column (1.8 µm, 2.1 × 50 mm) with a gradient elution system (ACN and 0.1 % formic acid-water). An electrospray ionization (ESI) was used for mass spectrometer and operated in a full-scan mode at m/z 100 - 800. The data were collected in the positive ion mode and analyzed by the Masslynx 4.1 and SIMCA 13.0 software. Furthermore, an orthogonal partial least-squares discriminant analysis (OPLS-DA) using SIMCA 13.0 software was applied to investigate the differences between the blank and drug groups in bio-samples of rats (plasma, urine, feces). Totally 213 compounds including 41 prototype ingredients, 107 phase I and 65 phase II metabolites were detected, according to the MS and MS/MS data. Among them, 134 metabolites are potential new compounds.

Systematic analysis of the metabolites of Angelol B by UPLC-Q-TOF-MS after oral administration to rats.

Angelicae Pubescentis Radix (APR), a widely used traditional Chinese medicine (TCM), is mainly used to treat rheumatism and headache diseases. Angelol B is one of the bioactive constituents of APR with significant anti-inflammatory activity. This paper is aimed to illustrate the metabolites of angelol B in vivo. To achieve this objective, a metabolomics approach based on a rapid and accurate UPLC-Q-TOF-MS method was used to detect the metabolites of Angelol B in rat. A gradient elution system (ACN and 0.1% formic acid water) equipped with an Agilent SB-C18 column (1.8 µm, 2.1 mm × 50 mm) to complete the separation. Scanning area at m/z 100.800 operated on an electrospray ionization (ESI). The data were collected in both positive and negative ion mode and analyzed by the Masslynx 4.1 and SIMCA 13.0 software. A total of 31 metabolites including 20 phase I and 11 phase II. metabolites were identified. Their structure and fragmentation process were deduced based on the MS and MS/MS data. All of thirty-one metabolites are new compounds based on the search of SCI-Finder database.