Chinese Journal of Analytical Chemistry最新文献

Objective

To investigate the mechanism of GanZhiRong granule(GZR)in the treatment of type 2 diabetes mellitus (T2DM).

Methods

Network pharmacology was used to explore the target and signal pathway of GZR in T2DM. Cell experiments were conducted to observe the inhibitory effects of GZR on oxaloacetic acid on pyruvate glycoisogenesis, triglyceride and glucose release, and the inhibitory effects of GZR on palmitic acid (PA) induced apoptosis of HepG2 cells. The main components in GZR were identified and compared by liquid chromatography-mass spectrometry.

Results

Network pharmacological methods were used to explore the targets and signaling pathways of T2DM treated with GZR, and it was found that CA4, CA7, CA2, AKR1B1 and other targets were closely related to T2DM treated with GZR. Gene Ontology (GO) and Kyoto Encyclopedia Genes and Genomes (KEGG) pathway enrichment analysis indicated that GZR may directly regulate the development of T2DM through lipid atherosclerosis and apoptosis. In vitro results showed that GZR has a certain protective effect on PA-induced damage of HepG2 cells in a dose-dependent manner. In addition, GZR can effectively inhibit the increase of triglyceride and glucose contents in PA-induced HepG2 cells, decrease the contents of pyruvate and oxaloacetic acid, and significantly increase the content of acetyl-coA. The main components were identified and compared. 32 components were identified, including salvianolic acid B, D-hydrothreose, proanthocyanidin, shikimic acid, salvianolic acid A, salvianolic acid C, 7 glycosides of calycoflavone, 3′-methoxy puerarin, 3′-hydroxypuerarin, apigenin-7-o-β-D.

Conclusion

The treatment of T2DM with GZR is related to lipid metabolism and cell apoptosis.

Acquiring insight into the transport of water clusters across cytomembrane is vital and essential for elucidating cell functions and water channels. Herein, A highly sensitive living cell analysis platform was developed for monitoring the transport dynamics of water clusters through water channels by combining the piezoelectric transducer and the hypotonicity-caused cell volume regulation. The various drinking water was used as the hypotonic perfusate to stimulate vascular endothelial cells and the temporal frequency response to cells was obtained to analyze the transport rate of the influx and efflux of water clusters which is related to water structure. The sensor is capable to distinguish the transport dynamics of different water clusters in five drinking water which the transport rates of water influx of cells are 5.1 ± 0.40, 6.6 ± 0.96, 7.4 ± 0.46, 8.1 ± 0.86, and 8.4 ± 0.80 Hz min⁻¹ (n = 3), respectively, showed that they are ranked in the increasing order: M-water, C-water, S-water, RO-water, d-water. Moreover, inhibitor of HgCl₂ was used to block water channels to reveal the water transport via water channels. Conductivity and infrared spectroscopy assays further confirmed the differences of transport dynamics between these drinking water due to the structure or size of water clusters caused by the mineral substance or the electromagnetic field. Therefore, this work provides a novel, simple and effective method for monitoring the transport of different water cluster across cytomembrane.

Although formaldehyde has been widely used in industry, the excessive or residual formaldehyde has been proven to cause irreversible harm to human beings due to its high toxicity. To solve this problem, we studied oxalyldihydrazide as an analytical reagent to determine formaldehyde by ultraviolet and visible (UV-vis) spectrophotometry. In this study, hydrazine compounds with –NH–NH₂ structures can react with formaldehyde to form hydrazone (including –NH–N=CH–), water is the only by-product. Therefore, oxalyldihydrazide can not only react with formaldehyde but also sense its analogs such as acetaldehyde, acetone, and benzaldehyde in solution, and detect them by UV-vis spectrophotometry at 220 nm, 226 nm, 262 nm, and 257 nm respectively. Among them, the limit of detection (LOD) of formaldehyde is calculated to be 0.03 ppm (LOQ = 0.03 ppm) with the relative standard deviation (RSD) of 1.58%. Meanwhile, the above-mentioned method can be used for detecting formaldehyde in clams with excellent selectivity and sensitivity.

Comprehensive characterization of lipid structures is of significance, as they play a key role in numerous biological processes. Mass spectrometry (MS) emerges as a preferred tool for lipid analysis, providing good performance in sensitivity and accuracy. However, characterization of unsaturated lipids still has certain difficulties due to structural diversity. In this work, combining epoxidation and tandem MS was developed for unsaturated lipids analysis with high structural specificity. By using the proposed method, it could simultaneously produce high-abundance diagnostic ions specific to lipid C=C locations and sn-positions, facilitating lipid isomers identification. Determining C=C location and sn-position isomers of lipid in a single spectrum can be achieved, which is valuable for discovery of great structural diversity. The capability of this approach in characterizing unsaturated lipids at high structural level has been illustrated with different standards including a lipid extract from complex biological sample. The relative quantitation capability of C=C location and sn-position isomers was also demonstrated based on diagnostic ion intensities.

Metal-organic frameworks (MOFs) are hybrid materials composed of both organic and inorganic elements. MOF materials, because of their unique structures and properties, such as controllable pore size, large surface area, excellent catalytic activity, and high density of active sites, are applied in electrochemical sensors systems for the sensitive, quick, and low-cost detection of multiple analytes. MOFs, with their high specific surface area, controllable shape, and adjustable pore volume, will provide strong interaction with compounds via abundant functional groups, leading to increased selectivity for electrochemical determination of a wide range of compounds. In this review, the structure, synthesis methods, characterization, and the applications of MOFs in recent years as sensing material in fabricating sensors for detecting drugs, pesticides, heavy metals, food additives, and other contaminants are summarized, compared, and discussed. Also, MOFs were used in numerous antibacterial application areas due to their long-term release pore volume, capability, and stretch ability when integrated with a wide range of compounds and/or substances (including nanostructures, phytochemicals, antibiotics, and polymers). This review also provides a comprehensive overview of the antibacterial uses of MOFs and one's composite materials, with a focus on the different kinds of MOF nanocomposite and their antibacterial influence in various uses.

RNA-binding proteins (RBPs) play central roles in the regulation of gene expression in eukaryotes. The elucidation of complex RNA‒protein interaction patterns and specific binding sites has been the subject of intensive research in recent years. However, large-scale RNA‒protein binding site (RBS) identification remains an urgent issue due to the lack of broad and unbiased RBP enrichment methods. In this study, a novel strategy for RBS identification was developed by using a psoralen probe (PP) for large-scale RBP enrichment. A total of 1957 high-confidence RBPs with good reproducibility were identified via mass spectrometry. A total of 1783 protein groups (91.1%) were previously annotated as RBPs. To identify RBSs, the enriched RBPs were treated with two different methods: digestion via ribonucleases (RNases) or hydrofluoric acid (HF). A total of 448 high-confidence RBSs were identified by using the former strategy, and 1301 high-confidence RBSs were identified by using the latter method. By comparing the identification results of cross-linking sites in both methods, it was observed that the binding of RNA to RBP was less likely to occur on acidic amino acids. Furthermore, the HF method can identify RBS in a more unbiased manner than the RNase method. The above mentioned results suggest the potential of both methods for large-scale RBS identification.

The analysis of dissociation products of disulfide bonds in peptide sequences has been increasingly applied in various fields. Ion dissociation is typically performed by tandem mass spectrometry, in which the overall molecular weight is determined during the first stage and the protein sequence and structure are obtained by dissociation during the second stage. However, conventional dissociation methods have some disadvantages, such as insufficient dissociation efficiency, and low product signals and varieties. Ultraviolet photodissociation (UVPD) is a rapid, efficient, and practical dissociation method for protein analysis, which excites the biomolecule skeleton and then directly excites the molecules, forming the excited states within microseconds. Although the development of mass spectrometer platforms coupled with UVPD has been reported to date, most of these studies have focused on the application of UVPD in mass spectrometry (MS). Discussions on the experimental setup for UVPD lasers, including the trigger process of the ultraviolet (UV) laser, the timing sequence of the entire dissociation and detection process, and their influence on dissociation, are limited. Therefore, an instrument platform was developed with a linear ion-trap mass spectrometer and an excimer laser to achieve UVPD by adjusting the laser trigger signal. The platform dissociated the disulfide bond of the amino acid sequence ARACAKA-ECG into two characteristic valence states (m/z = 498 and 332), and their highest intensities were obtained by optimizing the experimental conditions of the platform. The dissociation results of UVPD showed the characteristic peaks of ARACAKA (m/z 345) that were produced by disulfide bond cleavage, but these peaks were not detected by collision-induced dissociation (CID). Therefore, it was confirmed that the developed platform realized UVPD of the disulfide bond of the amino acid sequence of the polypeptide. Moreover, the developed platform provides a reference for the implementation of UVPD for peptide sequencing.

MicroRNAs (miRNAs) are crucial for various basic cellular processes and have been regarded as an important indicator for pathogenesis and development of cancer. While miRNAs are characterized by short sequence length, large single cell copy number variation, low abundance in vivo, and high homologous sequence similarity. The development of miRNA detection methods with high sensitivity, good selectivity and low cost is the key to study the function of miRNA. In this article, a method combining isothermal chain replacement amplification and G-quadruplex (G4) specific detection is developed for highly specific and sensitive detection of miRNA. By designing proper DNA sequences, a three-stranded DNA complex was formed and produced a lot of G4 structure sequences, which can be stained by specific fluorescence dye and quantified. In the experiment, the fluorescence dye shows extremely high specificity, which brings excellent signal discrimination, so that the target miRNAs can be accurately detected. Experiments under high background noise also verified this method is highly selective for target miRNAs. This method holds great imagination in expanding the detection methods to more platforms, such as nanopore sensors, because it alters the secondary structure of DNA sequences.