Preparation of Fe3O4@SW-MIL-101-NH2 for selective pre-concentration of chlorogenic acid metabolites in rat plasma, urine, and feces samples

Components analysis of San-Bai decoction, and its pharmacodynamics and mechanism on preventing and treating melasma

ETHNOPHARMACOLOGICAL RELEVANCE

San-Bai Decoction (SBD) is a classic whitening prescription originally recorded in the 'Introduction to Medicine' of the Ming Dynasty. SBD has been known for invigorating Qi and blood, promoting spleen and stomach, whitening skin, and fading melasma. However, its pharmacodynamic material basis and specific mechanism remain unclear.

AIM OF THE STUDY

The aim of this study is to clarify the pharmacodynamic material basis of SBD and its mechanism of removing melasma.

MATERIALS AND METHODS

The positive and negative ion mass spectrum data of SBD extract were collected by UHPLC-Q-Exactive Orbitrap MS/MS, imported into Compound Discoverer (CD) 3.1 software, matched through the online database, and manually checked. Finally, the in vitro chemical components of SBD were classified. Similarly, the mass spectrum data of SBD in the serum of normal rats and melasma model rats were also analyzed by CD 3.1 software. The in vitro identified Compound file of SBD was imported into the Expected Compounds and the Generate Expected Compounds project was selected. The SBD compounds were then chosen under the Compound Section. All phase I and II reaction types related to SBD components were selected, and the metabolic platform of CD 3.1 software was utilized to process the results and obtain possible metabolites. The metabolites were scored and products with high scores were subsequently screened. According to literature comparison, the final metabolites of SBD in both normal rats and melasma model rats were determined and comprehensively analyzed. The Melasma model rats were constructed through intramuscular injection of progesterone and ultraviolet radiation B (UVB) irradiation. The preventing and treating effect of SBD on melasma were evaluated by regulating inflammation, epidermal collagen content, and oxidative stress. Additionally, the effect of SBD on the Phosphatidylinositol 3-kinase (PI3K)/Protein kinase B (Akt)/Glycogen synthase kinase 3β (GSK3β) pathway was investigated through Western blot (WB) to explore its underlying mechanism on whitening and removing melasma efficacy.

RESULTS

Ultimately, 94 components were identified in SBD, including 41 flavonoids, 27 organic acids, and 9 glycosides, 3 terpenoids, 2 amides, 2 aldehydes, 1 phenylpropanoid and 9 other compounds. In the blood of normal rat group, a total of 24 prototype components and 61 metabolites were identified. Similarly, there were19 prototype components and 44 metabolites identified from the blood of melasma model rats. Pharmacodynamic experiment results indicated that SBD effectively reduced the incidence of melasma, prevent the loss of epidermal collagen, and elevate the activity of superoxide dismutase and decrease the malondialdehyde content in both liver and skin. Interestingly, the WB results demonstrated that SBD effectively activated PI3K/Akt/GSK3β pathway, and down-regulated the expression of melanin-related proteins.

CONCLUSIONS

For the first time, the components of SBD extracts, and its prototype components and metabolites in the blood of normal rats and melasma model rats were successfully identified by high-resolution liquid chromatography-mass spectrometry with CD software. Additionally, the differences of in vivo components of SBD between normal rats and melasma model rats were analyzed. The preventive and therapeutic effect of SBD on melasma was verified in the melasma model rats induced by progesterone and UVB irradiation, and its mechanism was related to activating PI3K/Akt/GSK3β pathway and downregulating the expression of melanin-related proteins. These results provide an experimental foundation for further research on the pharmacodynamic substance basis and pharmacodynamic mechanism of SBD, as well as developing new anti-melasma formula with SBD.

Boronic acid-functionalized magnetic covalent organic frameworks based solid-phase extraction coupled with hydrophilic interaction chromatography-tandem mass spectrometry for the determination of trace gentamicin residues in milk

Boric acid-functionalized magnetic covalent organic frameworks (Fe3O4-TpBD-B) with large surface area and high porosity were prepared and applied for magnetic solid-phase extraction adsorbent of gentamicin from milk before UPLC-MS/MS detection. By utilizing a new HILIC chromatographic column with zwitterionic sulfoalkyl betaine stationary phase based on ethyl bridged hybrid particles (BEH), isomers of gentamicin (C1, C1a, and C2+C2a components). The developed methods demonstrated good linearity (R2 > 0.99), acceptable accuracy and good precision (<10 %), and low limit of quantitation (1.59 ng mL⁻1 for C1, 1.52 ng mL⁻1 for C1a and 2.72 ng mL⁻1 for C2+C2a). In addition, this method has been effectively applied to the analysis of real milk samples.

One-pot derivatization/magnetic solid-phase extraction combined with high-performance liquid chromatography-fluorescence detection for rapid analysis of biogenic amines in alcoholic beverages

The determination of biogenic amines (BAs) in alcoholic beverages is crucial for assessing their health impact, ensuring beverage quality, and guaranteeing safety. Herein, a rapid one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method was proposed using 6-aminoquinolinyl-N-hydroxysuccinimide carbamate as the derivatization reagent and magnetic hydroxyl-functionalized multi-walled carbon nanotubes as the extraction material. Integration of derivatization and extraction steps simplifies the sample preparation process, taking only three minutes and eliminating the need for centrifugation by utilizing magnetic sorbent. The resulting desorption solution was directly analyzed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD) without any evaporation or reconstitution steps. The integrated OPD/MSPE-HPLC-FLD method demonstrates excellent linearity (R2 > 0.992), accuracy (relative recoveries: 85.1-109.2%), precision (RSDs≤9.7%) and detection limits (limits of detection: 0.3-2 ng/mL). It has been successfully applied to determine free BAs in various alcoholic beverages, including red wine, Baijiu, Huangjiu, and beer. This method enables rapid, sensitive and precise analysis of BAs in alcoholic beverages.

Applications of magnetic solid-phase extraction in the sample preparation of natural product analysis (2020-2023)

Sample preparation, including extraction, separation, and purification, is a vital process for natural product analysis. As an attractive sample pretreatment method, magnetic solid-phase extraction (MSPE) has gained plenty of attention, mainly due to its simpler operation, less consumption of organic solvents, and shorter processing time than traditional SPE. This updated review is devoted to summarizing the applications of MSPE based on different magnetic nanomaterials in the analysis of various natural products in complex matrixes, such as biological samples, plants, and Chinese herbal preparations in the past four years (2020-2023). The preparation and fabrication of different materials are briefly introduced. Furthermore, the extraction mechanism and interaction forces between adsorbent and analytes are elaborated, and the advantages and disadvantages of different adsorbents coupled with various analytical methods for MSPE of different natural products are summarized. Moreover, the future trends and opportunities for MSPE in the natural product analysis are discussed. It is expected that this work can provide updated information for future research on the applications of MSPE in such fields.

Magnetic solid-phase extraction based on polydopamine-coated magnetic nanoparticles for rapid and sensitive analysis of eleven illicit drugs and metabolites in wastewater with the aid of UHPLC-MS/MS

The quantification of illicit drugs in wastewater has become a valuable tool for monitoring illicit drug abuse. The commonly utilized methods for detecting drugs in wastewater require a substantial sample volume, extended pretreatment durations, and intricate procedures. This study first employed polydopamine-coated magnetic nanocomposites as adsorbents for magnetic solid-phase extraction, combined with UPLC-MS/MS, to simultaneously determine the concentrations of eleven common illicit drugs in wastewater. The synthesis process for Fe3O4@PDA is straightforward and high-yield. Benefiting from the strong magnetic response, good dispersibility, and abundant binding sites of the prepared nanocomposites, the extraction of illicit drugs from wastewater could be achieved in just 15 min. The method exhibited satisfactory limits of quantitation (ranging from 5 to 10 ng/L), commendable accuracy (ranging from 90.59 % to 106.80 %), good precision (with RSDs below 10 %), and less sample consumption (only 1 mL). The efficacy of this method was successfully validated through its application to actual wastewater samples collected from ten wastewater treatment plants. The results indicated that morphine, codeine, methamphetamine, and ketamine were the predominant illicit drugs present in the samples. The method developed is able to meet the needs of common illicit drug monitoring and high-throughput analysis requirements.

Genetically Engineered Cell Membrane-Coated Nanoparticles with High-Density Customized Membrane Receptor for High-Performance Drug Lead Discovery

Cell membrane coating strategies have been increasingly researched due to their unique capabilities of biomimicry and biointerfacing, which can mimic the functionality of the original source cells in vivo but fail to provide customized nanoparticle surfaces with new or enhanced capabilities beyond natural cells. However, the field of drug lead discovery necessitates the acquisition of sufficient surface density of specific target membrane receptors, presenting a heightened demand for this technology. In this study, we developed a novel approach to fabricate high density of fibroblast growth factor receptor 4 (FGFR4) cell membrane-coated nanoparticles through covalent site-specific immobilization between genetically engineered FGFR4 with HaloTag anchor on cell membrane and chloroalkane-functionalized magnetic nanoparticles. This technique enables efficient screening of tyrosine kinase inhibitors from natural products. And the enhanced density of FGFR4 on the surface of nanoparticles were successfully confirmed by Western blot assay and confocal laser scanning microscopy. Further, the customized nanoparticles demonstrated exceptional sensitivity (limit of detection = 0.3 × 10-3 μg mL-1). Overall, the proposed design of a high density of membrane receptors, achieved through covalent site-specific immobilization with a HaloTag anchor, demonstrates a promising strategy for the development of cell membrane surface engineering. This approach highlights the potential of cell membrane coating technology for facilitating the advanced extraction of small molecules for drug discovery.

Ultra-High Adsorption Capacity of Core-Shell-Derived Magnetic Zeolite Imidazolate Framework-67 as Adsorbent for Selective Extraction of Theophylline

A core-shell-derived structural magnetic zeolite imidazolate framework-67 (Fe₃O₄-COOH@ZIF-67) nanocomposite was fabricated through a single-step coating of zeolite imidazolate framework-67 on glutaric anhydride-functionalized Fe₃O₄ nanosphere for the magnetic solid-phase extraction (MSPE) of theophylline (TP). The Fe₃O₄-COOH@ZIF-67 nanocomposite was characterized through scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, Zeta potential analysis, X-ray diffraction, Brunauer-Emmett-Teller, and vibrating sample magnetometer. The material has a high specific surface area and good magnetism, which maintains the regular dodecahedron structure of ZIF-67 without being destroyed by the addition of Fe₃O₄-COOH nanospheres. The Fe₃O₄-COOH@ZIF-67 can rapidly adsorb TP mainly through the strong coordination interaction between undercoordinated Co²⁺ on ZIF-67 and -NH from imidazole of TP. The adsorption and desorption conditions, such as the amount of adsorbent, adsorption time, pH value, and elution solvent, were optimized. The kinetics of TP adsorption on Fe₃O₄-COOH@ZIF-67 was found to follow pseudo-second-order kinetics. The Langmuir model fits the adsorption data well and the maximum adsorption capacity is 1764 mg/g. Finally, the developed MSPE-HPLC method was applied in the enrichment and analysis of TP in four tea samples and rabbit plasma. TP was not detected in oolong tea and rabbit plasma, and its contents in jasmine tea, black tea, and green tea are 5.80, 4.31, and 1.53 μg/g, respectively. The recoveries of spiked samples are between 74.41% and 86.07% with RSD in the range of 0.81-3.83%. The adsorption performance of Fe₃O₄-COOH@ZIF-67 nanocomposite was nearly unchanged after being stored at room temperature for at least 80 days and two consecutive adsorption-desorption cycles. The results demonstrate that Fe₃O₄-COOH@ZIF-67 nanocomposite is a promising magnetic adsorbent for the preconcentration of TP in complex samples.