Multi-component pharmacokinetic study of prunus mume fructus extract after oral administration in rats using UPLC-MS/MS.

Prunus mume fructus (MF) is used in traditional Chinese medicine and food, as it exerts pharmacological effects, such as antibacterial, antioxidant, antitumour, thirst-relieving, and antidiarrheal effects. In the present study, a reliable and sensitive ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of 16 prototype components (L-(-)-malic acid, 3,4-dihydroxybenzaldehyde, protocatechuic acid, vanillic acid, caffeic acid, D-(-)-quinic acid, citric acid, ferulic acid, syringic acid, cryptochlorogenic acid, neochlorogenic acid, chlorogenic acid, amygdalin, maslinic acid, corosolic acid, and rutin) in rat plasma after oral administration of the MF extract. Plasma samples were prepared via protein precipitation using acetonitrile. The 16 components were separated on an ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm) with a gradient mobile phase system of methanol and 0.1% (v/v) formic acid aqueous solution at a flow rate of 0.3 ml/min. All components were quantitated using Agilent Jet Stream electrospray ionisation in negative ion mode. The intra-day and inter-day accuracies ranged from-9.4 to 9.4%, and the precision of the analytes was less than 14.8%. The extraction recovery rate of the analytes ranged from 63.59 to 109.44% and the matrix effects ranged from 49.25 to 109.28%. Stability studies proved that the analytes were stable under the tested conditions, with a relative standard deviation lower than 13.7%. Hence, the developed method was successfully applied to evaluate the pharmacokinetics of 16 components in the MF extract after oral administration in rats using UPLC-MS/MS.

Comparative Investigation of the Differences in Chemical Compounds between Raw and Processed Mume Fructus Using Plant Metabolomics Combined with Chemometrics Methods.

Mume Fructus is a well-known herbal medicine and food with a long history of processing and application. Different processing methods impact the intrinsic quality of Mume Fructus. Thus, it is of great significance to investigate the changes in chemical components during processing (i.e., raw compared to the pulp and charcoal forms). In this study, plant metabolomics methods based on mass spectrometry detection were established to analyze the chemical ingredients of Mume Fructus comprehensively. Chemometric strategies were combined to analyze the profile differences of Mume Fructus after different processing methods. The established strategy identified 98 volatile and 89 non-volatile compounds of Mume Fructus by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS), respectively. Moreover, the orthogonal partial least squares discriminant analysis (OPLS-DA) indicated that raw Mume Fructus and the Mume Fructus pulp and charcoal were distributed in three regions. Subsequently, 19 volatile and 16 non-volatile components were selected as potential chemical component markers with variable importance in the projection using (VIP) >1 as the criterion, and the accuracy was verified by a Back Propagation Neural Network (BP-NN). To further understand the difference in the content of Mume Fructus before and after processing, 16 non-volatile chemical component markers were quantitatively determined by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS). The results revealed that, compared with raw Mume Fructus, the total content of 16 components in the pulp of Mume Fructus increased while it decreased in the charcoal. Therefore, this study used GC-MS, UHPLC-Q-TOF-MS/MS and UHPLC-MS/MS modern technology to analyze the differences in chemical components before and after the processing of Mume Fructus and provided a material basis for further research on the quality evaluation and efficacy of Mume Fructus.

Synergetic Function of the Single-Atom Ru-N4 Site and Ru Nanoparticles for Hydrogen Production in a Wide pH Range and Seawater Electrolysis.

Hydrogen production by water splitting and seawater electrolysis is a promising alternative to develop clean hydrogen energy. The construction of high-efficiency and durable electrocatalysts for the hydrogen evolution reaction (HER) in a wide pH range and seawater is critical to overcoming the sluggish kinetic process. Herein, we develop an efficient catalytic material composed of a single-atom Ru-N4 site and Ru nanoparticles anchored on nitrogen-doped carbon (Ru1+NPs/N-C) through the coordination-pyrolysis strategy of the melamine formaldehyde resin. The Ru1+NPs/N-C catalyst shows outstanding HER activity with the smallest overpotentials, the lowest Tafel slopes, the highest mass activity and turnover frequency, as well as excellent stability in both acidic and alkaline media. Moreover, Ru1+NPs/N-C shows comparable hydrogen production performance and a higher faradic efficiency to 20% Pt/C in natural seawater and artificial simulated seawater. Theoretical calculations demonstrate that the strong synergistic effects between the Ru-N4 site and Ru nanoparticles modify the electronic structure to accelerate the HER kinetics. Ru nanoparticles can effectively realize dissociation of H2O to generate adsorbed hydrogen and also promote the single-atom Ru-N4 site to combine adsorbed hydrogen to H2 and desorption. This work provides a new perspective for designing high-efficiency hydrogen production electrocatalysts for large-scale seawater electrolysis.

Facile synthesis of hexagonal α-Co(OH)2 nanosheets and their superior activity in the selective reduction of nitro compounds.

Novel hexagonal α-cobalt hydroxide nanosheets are synthesized through a 2-methylimidazole-induced hydrolysis strategy with cetyltrimethylammonium bromide (CTAB) as a surfactant. The weak alkaline environment provides favorable conditions for the formation of metastable α-Co(OH)2, while the same raw material will produce ß-Co(OH)2 when a strong alkali solution is used. CTAB plays a vital role not only in hexagonal oriented growth, but also in the formation of the hydrotalcite-like structure of α-Co(OH)2 with high crystallinity. The crystallinity of both α- and ß-Co(OH)2 is very poor without CTAB as a surfactant. The Co in this Co(OH)2-x layer presents most of the CoII and a small part of the CoIII, and the interlayer nitrate anion balances the positive charge of the host layer. The redox function produced by the CoII and CoIII of α-Co(OH)2 together with the large layer spacing jointly promotes the electron and mass transfer. The use of hydrazine hydrate for transfer hydrogenation involves the transport of protons and electrons produced by decomposition, and the rapid transport is bound to be conducive to the reduction process. Nitro compounds with varieties of functional groups can be smoothly reduced to the corresponding amines with high selectivity, when α-Co(OH)2 was used as a catalyst under mild conditions.

Pharmacokinetic and Bioavailability Studies of Galgravin after Oral and Intravenous Administration to Rats Using HPLC-MS/MS Method.

This paper presents a new high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method with a rapid analysis of 6 min to determine the concentration of galgravin in rat plasma so as to study its pharmacokinetic features and bioavailability in vivo. Schisandrin was selected as the internal standard (IS). After extracting the analyte from plasma samples with ethyl acetate, methanol-H2O (0.1% formic acid) (85 : 15, v/v) was used as mobile phase to achieve chromatographic separation on a C18 reversed phase column. The MS detection was performed in positive ion mode using electrospray ionization (ESI) source. This method showed good linearity over the range of 1~500 ng/mL (R 2 > 0.999), and the lower limit of quantitation (LLOQ) was 1.0 ng/mL. The intraday precision and interday precision were both within 8.5%, whereas the accuracies were in the range of -2.6%-6.0%. The average recoveries of galgravin in rat plasma were between 92.3% and 99.3%. Moreover, galgravin was stable throughout storage and processing with all RSDs below 12.1%. After the successful application of this optimized method, the oral bioavailability of galgravin was determined to be 8.5%. This study will be helpful to the future research and development of galgravin.

Comparison of the chemical profile differences of Aster tataricus between raw and processed products by metabolomics coupled with chemometrics methods.

Aster tataricus, a traditional Chinese herb, has been used to treat cough and asthma for many years. Its raw and processed products have different pharmacological effects in clinical applications. To explore the chemical profile differences of components in A. tataricus processed with different methods, metabolomics methods based on ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry and gas chromatography-mass spectrometry were developed. Chemometrics strategy was applied to filter and screen the candidate compounds. The accuracy of differential markers was validated by back propagation neural network. The established methods showed that raw A. tataricus, honey-processed A. tataricus, vinegar-processed A. tataricus, and steamed A. tataricus were clearly divided into four groups, suggesting that the components were closely related to the processing methods. A total of 64 nonvolatile and 43 volatile compounds were identified in A. tataricus, and 22 nonvolatile and 12 volatile differential constituents were selected to distinguish the raw and processed A. tataricus. This study demonstrated that the metabolomics methods coupled with chemometrics were a comprehensive strategy to analyze the chemical profile differences and provided a reliable reference for quality evaluation of A. tataricus.

Metabolomics study on the periplocin-induced cardiotoxicity and the compatibility of periplocin and Panax notoginseng saponins in reducing cardiotoxicity in rats by GC-MS.

Periplocin, as one of the components of cardiac glycosides in Cortex periplocae, exhibited cardiotonic effects. Orally ingesting periplocin in high doses or over prolonged periods would cause serious adverse reactions, especially cardiotoxicity, which limits the applications of periplocin in clinical therapy. It has been reported that Panax notoginseng saponins could be used in compatibility with periplocin to reduce the cardiotoxicity of periplocin. To clarify the mechanisms of periplocin-induced cardiotoxicity and compatibility-pairing in reducing cardiotoxicity, the gas chromatography-mass spectrometry method was used to detect and analyze the metabolic profiles of rat plasma and urine samples after oral administration of periplocin, Panax notoginseng saponins, and the different compatibility ratios of periplocin and Panax notoginseng saponins. The multivariate statistical analysis method was used to screen and identify the biomarkers. A total of 49 potential biomarkers (28 in plasma and 21 in urine) associated with periplocin-induced cardiotoxicity were identified. Seven pathways were found through metabolomic pathway analysis. Moreover, the levels of 42 biomarkers (22 in plasma and 20 in urine) were close to normal after compatibility pairing. By analyzing the relative metabolic pathways, Panax notoginseng saponins could effectively reduce the cardiotoxicity of periplocin by affecting the tricarboxylic acid cycle, energy metabolism, and arachidonic acid metabolism.

Pharmacokinetic comparison of 15 active compositions in rat plasma after oral administration of raw and honey-processed Aster tataricus extracts.

A sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed and validated to clarify pharmacokinetic properties of 15 compounds (quercetin, isorhamnetin, chlorogenic acid, isoquercitrin, caffeic acid, scopoletin, 7-hydroxycoumarin, shionone, ferulic acid, kaempferol-7-O-ß-d-glucopyranoside, methyl caffeate, luteolin, kaempferol, epifriedelinol, and protocatechuic acid) in raw and honey-processed Aster tataricus. Separation was carried out on an ACQUITY UPLC® BEH C18 column (2.1 × 100 mm, 1.7 µm) using a gradient elution with mobile phase constituting 0.1% formic acid-water and 0.05% formic acid-methanol. Quantitative analysis was performed using multiple reaction monitoring detection in both positive and negative ionization modes. Calibration curves showed good linearity (r2  > 0.991) over the corresponding concentration range. The intra- and interday precisions were within 10.1%, and accuracy ranged from -11.4 to 12.4%. The extraction recoveries and matrix effects were 78.1-100.0% and 81.1-113.7%, respectively. The analytes were stable under four storage conditions with relative standard deviations less than 12.6%. The validated method was successfully applied to compare the pharmacokinetic behaviors of raw and honey-processed Aster tataricus for the first time. The results indicated that the areas under the curve (AUCs) of shionone, ferulic acid, and protocatechuic acid in honey-processed A. tataricus group were significantly lower than that of raw A. tataricus group.