International Journal of Analytical Chemistry最新文献

Acetylcorynoline is an alkaloid isolated from the tubers of Corydalis ambigua Cham. et Schltdl. It has anti-inflammatory properties with the potential to treat Parkinson's disease. However, the use of UPLC-MS/MS for identifying acetylcorynoline in mouse plasma has not yet been explored. The present study aimed to develop a fast and selective method for determining the amount of acetylcorynoline in mouse plasma using UPLC-MS/MS. Plasma samples (10 μL) were prepared using methanol-induced protein precipitation following the addition of aconitine as an internal standard. The chromatographic separation was accomplished using a UPLC HSS T3 column with acetonitrile and 0.1% formic acid as the mobile phase. The analytes were run for 4.0 min in total. The target fragment ions m/z 410.4 ⟶ 350.3 for acetylcorynoline and m/z 646.6 ⟶ 586.5 for internal standard were used for quantification using multiple reaction monitoring mode. The mouse blood was obtained at different time points after intravenous (5 mg/kg) and oral (20 mg/kg) administration of acetylcorynoline. The calibration plots for acetylcorynoline in mouse plasma showed a linear trend over the whole range of 1-2000 ng/mL. Both the intraday and interday precision relative standard deviations were less than 11%. The half-life in mice was found to be 2.6 ± 0.7 h and 2.7 ± 0.8 h following oral and intravenous administration, respectively. The bioavailability was determined to be 58.9%. The pharmacokinetics and bioavailability of acetylcorynoline in mice were effectively analyzed using this UPLC-MS/MS method, which had a runtime of 4 min per sample and required only 10 μL of plasma.

Bistorta amplexicaulis (D.Don) Greene from the family Polygonaceae is an important medicinal plant species. The growing therapeutic use of B. amplexicaulis has led to its population depletion thus requiring its conservation. Herein, an efficient, reproducible and reliable propagation protocol system was established for B. amplexicaulis using nodal segments as explant. Various culture media were tested for the assessment of growth and development of this plant species. On the shoot proliferation and rhizogenesis of regenerated B. amplexicaulis plantlets, the effects of several plant growth regulators (PGRs) were assessed. Direct organogenesis from nodal segments was achieved by culturing the nodal explants on Murashige and Skoog medium supplemented with 2.0 mg·L^-1 6-benzylaminopurine (BAP). Shoot multiplication was widely affected by the kind and concentration of PGRs, and the subculturing of in vitro regenerated shootlets on fresh medium. After incubation for 4 weeks at optimum BAP concentration, cultures were transferred to secondary medium with BAP (optimized concentration) supplemented with different auxins (indole acetic acid, indole butyric acid, and naphthalene acetic acid [NAA]). Murashige and Skoog medium enriched with 2.0 mg·L^-1 BAP showed the highest shoot induction response (83% ± 3.61%) with mean shoot number (4.67 ± 1.45) and shoot length of 4.33 ± 1.45 cm. Growth medium fortified with 1.0 mg·L^-1 α- NAA exhibited maximum rhizogenesis with 4.33 ± 0.88 roots and average root length as 5.50 ± 0.76 cm from regenerated B. amplexicaulis shoots. Acclimatized plants of B. amplexicaulis showed 90% survival. The projected protocol may serve as a treasured tool for the rapid and large-scale multiplication of elite B. amplexicaulis and for germplasm conservation to ensure continuous supply of this plant amid the increasing demand.

Objective: This study aims to use bioinformatics and machine learning algorithms to screen and analyze the key genes involved in venous thromboembolism (VTE) and explore the relationship between these biomarkers and immune cell infiltration. Methods: The gene expression profile with the identifier GSE19151 was downloaded from the GEO database. Differential expression analysis using the limma package was conducted to identify genes that were differentially expressed between VTE and normal samples. Biological activities of these genes were then investigated through GO analysis utilizing the R language package. KEGG and GSEA were also performed to identify key signaling pathways. Furthermore, machine learning techniques were employed to determine hub gene signatures related to VTE, and ROC curves were used to validate the findings. To compare the immune infiltration of healthy and VTE samples, single sample gene set enrichment analysis (ssGSEA) was applied. Lastly, the Spearman correlation coefficient was used to assess the relationship between the expression of hub genes and immune cell infiltration. Results: A total of 628 differentially expressed genes (DEGs) were discovered between the VTE samples and normal samples. GO analysis identified protein polyubiquitination, lysosomal lumen acidification, organellar ribosome, mitochondrial ribosome, ammonium transmembrane transporter activity, and immunoglobulin binding as the processes with the highest abundance of DEGs. KEGG pathway analysis revealed that DEGs were enriched in ribosome, COVID-19, viral infection, oxidative phosphorylation, Parkinson's disease, nonalcoholic fatty liver disease, apoptosis, and cancer. The most prominent KEGG pathways associated with VTE were ribosome, Parkinson's disease, oxidative phosphorylation, Alzheimer's disease, and Huntington's disease according to GSEA findings. DLST and LSP1 were identified as hub gene signatures in VTE by machine learning integrative analysis, and ROC curves confirmed their diagnostic value. Results from ssGSEA indicated a significant difference in the degree of immune cell infiltration between VTE and normal samples, with the expression of DLST and LSP1 positively correlated with the content of some immune cells. The R package, code, and analysis results used in this paper are available on https://github.com/doctorlaby/my-project. Conclusion: Our research is the first to utilize machine learning techniques in identifying DLST and LSP1 as significant biomarkers of VTE. With our findings, we have uncovered new insights into the underlying causes of VTE and potential treatments for affected patients.

Amyloid nanofibrils are long and thin strands with cross β structures associated by hydrogen bonds. These structures can be formed under suitable conditions commonly at low pH and high temperatures. Fibrillated pinto bean protein isolate (FPBPI) was made by heating pinto bean protein at 85°C in an acidic condition while gently stirring at initial protein solution concentrations of 4 mg/mL, 13 mg/mL, and 21 mg/mL. Freeze-dried FPBPI's physicochemical, structural, and thermal characteristics were assessed, and they were compared with a native pinto bean protein isolate (PBPI) as a control. An increase in Congo red spectral absorption at 544 nm was observed following the fibril formation process. The largest concentration of freeze-dried fibrillated protein exhibited the highest Congo red spectral absorption. Fibrillar proteins' Fourier transform infrared (FTIR) spectrograms with lower wave numbers were seen than the native protein. For native PBPI, transmission electron microscopy (TEM) images were globular in shape, but they changed to long and curly morphologies in fibrillated proteins. FPBPI has a lower melting enthalpy than native protein when measured by differential scanning calorimetry (DSC). With the rising initial protein content, the enthalpy rose. Concurrently, semicrystalline structure for native and fibrillated pinto bean proteins was revealed by X-ray diffraction (XRD) findings. As the original protein concentration grew, so did the crystallinity intensity. Water-holding capacity (WHC) and oil-holding capacity (OHC) of freeze-dried FPBPI were higher than those of native protein. So, fibrillation of pinto bean protein helped it to serve as a good thickener in food industries.

Based on the effectiveness, measurability, and traceability of the quality marker (Q-marker) theory of traditional Chinese medicine, the Q-marker of Lycii Cortex (LC) was preliminarily predicted and analyzed. A UPLC-Q-TOF-MS qualitative analysis method for LC samples was established. A total of 44 LC chemical components, 16 plasma prototype components, 25 urine prototype components, and 27 fecal prototype components were identified. At the same time, the "component-target-disease" network diagram was constructed by network pharmacology to predict the potential active components of LC. A UPLC-MS/MS quantitative analysis method was established to determine the contents of 11 components such as kukoamine A in 35 batches of LC from seven producing areas. Principal component analysis, orthogonal partial least squares discriminant analysis, and other mathematical analysis methods were used to screen the differential components. Based on the comprehensive consideration of the Q-marker traceability, transitivity, specificity, effectiveness, and measurability, kukoamine A and kukoamine B were preliminarily predicted as LC potential Q-markers, and the high-quality producing area was determined to be Chengcheng County, Weinan City, Shaanxi Province. The prediction analysis of the LC Q-marker provides a reference for the comprehensive control of the quality of LC medicinal materials and also lays a foundation for the research and exploration of the substance basis and mechanism of action of LC.

Herein, a micro-solid-phase extraction (μSPE) method was developed using a pipette tip for rutin extraction, employing activated hollow carbon nanospheres (HCNSs) as the sorbent. Characterization of the activated carbon nanospheres through TGA, FTIR, and SEM analysis confirmed the success of the activation process. The study demonstrated the efficacy of PT-μSPE in rutin extraction under pH 2 conditions with a standard concentration of 2 mg·L^-1. The optimal mass of HCNSs was found to be 2 mg, and a loading volume of 500 μL resulted in the maximum recovery of rutin. Propan-2-ol was the best elution solvent with 15 aspirating/dispensing cycles. The correlation of determination (R ²) for the calibration curve was found to be 0.9991, and the LOD and LOQ values were 0.604 and 1.830 mg·L^-1, respectively. The applicability of the method was demonstrated by extracting rutin from a complex Moringa oleifera leaf extract with the relative standard deviation (RSD) of 3.26%, thereby validating this method as feasible for the extraction of useful bioactive compounds from complex plant samples.

In this study, spectrophotometric determination of donepezil and rivastigmine in healthy human urine samples was carried out by the statistical method. Partial least squares (PLS) and principal component regression (PCR) from multivariate calibration methods were used to evaluate the data obtained from the UV-Vis spectroscopy analysis of the urine sample. Mixtures of each early substance were prepared prior to urine sample analysis, and simultaneous determination of donepezil and rivastigmine was performed on the established chemometric model without any prior separation. The calibration curves of each drug were analyzed, and linearity values were also analyzed. For donepezil and rivastigmine, they were 0.9989 and 0.9997, respectively, and were linear over the concentration range of the synthetic mixture. When both chemometric methods (PLS and PCR) were evaluated in terms of accuracy and reproducibility, very high recoveries and small standard deviations were determined. In the PLS method, the standard error of prediction (SEC), the sum of the prediction residual errors (PRESS), the limit of quantitation (LOQ), and the limit of detection (LOD) values were 0.015, 0.0030, 0.067, 0.24, 0.018, 0.0042, 0.089, and 0.301 for donepezil and rivastigmine, respectively. In the PCR method, SEC, PRESS, LOD, and LOQ values are 0.016, 0.0054, 0.066, and 0.23 for donepezil and 0.022, 0.0062, 0.091, and 0.300 for rivastigmine. Chemometrics is used for speed, simplicity, and reliability. The proposed methods have been successfully applied to a sample of urine.

To explore the relationship between unsaturated fatty acid (UFA) content and parameters for microwave extraction, multimaterial and multiparameter testing was conducted in which five kinds of materials with different UFA contents (potato, wheat, corn, soybean, and peanut) were selected for the experiment. Four factors, namely, extraction temperature (X ₁), extraction time (X ₂), proportional volume of acetone (X ₃), and liquid-to-solid ratio (X ₄), were screened for their significant effects by using Prob > |T| values from the Plackett-Burman experiment. A microwave extraction orthogonal experiment with four factors and five levels was designed separately using Design-Expert 8.05 software and them concentrated. Microwave-accelerated methyl esterification was then performed, and the UFA content was determined via gas chromatography (flame ionization detector). The optimal extraction conditions (X ₁, X ₂, X ₃, X ₄) and the optimal UFA content of potato were 80.68°C, 10.74 min, 0.80, 3.25 mL × g^-1, 1.08%; wheat: 80.81°C, 10.54 min, 0.80, 20.91 mL × g^-1, 2.26%; corn: 81.18°C, 9.93 min, 0.80, 50.94 mL × g^-1, 6.89%; soybean: 82.07°C, 9.07 min, 0.80, 93.87 mL × g^-1, 15.81%; and peanut: 83.12°C, 8.11 min, 0.80, 168.70 mL × g^-1, 33.07%. Then, the optimization results for the five kinds of materials were synthesized by Origin 8.0 software, the fitting degree of the cubic model with the four extraction factors was the highest, the determination coefficients were 0.9984, 0.9991, 0.8953, and 0.9989, the residual sums of squares were 0.2888, 0.1587, 0.8265, and 0.1864, and the correlation coefficients are ideal. The stability and accuracy of the model were verified by the orthogonal experiment of UFA extraction from rice, and the correlation coefficient between the predicted value and the actual value of the orthogonal experiment was 0.9998. This study systematically collates the optimal parameters for microwave extraction of UFA content in different crops from the perspective of multimaterial and multiparameter, which can provide a large amount of detailed basic data for microwave extraction technology.

Nonenzymatic and rapid monitoring of uric acid levels is of great value for early diagnosis, prevention, and management of oxidative stress-associated diseases. However, fast, convenient, and low-cost uric acid detection remains challenging, especially in resource-limited settings. In this study, a novel and rapid biosensing approach was developed for the simultaneous visualization and quantification of uric acid levels by using the unique surface plasmon resonance and photothermal property of 4,5-diamino-2-thiouracil (DT)-capped gold nanoparticles (AuNPs). With the presence of uric acid, DT-capped AuNPs rapidly aggregated, and a visible color/photothermal change was used for uric acid quantification within 15 min. The limit of detection was determined to be 11.3 and 6.6 μM for the dual-mode biosensor, leveraging the unique structure of DT to optimize reaction kinetics. Moreover, the sensor exhibited excellent anti-interference capabilities and demonstrated potential for detecting a wide range of uric acid concentrations in complex samples, thereby reducing the need for extensive sample dilution and complex material synthesis procedures. Furthermore, validation against gold standard testing indicates that this biosensor could serve as a highly sensitive assay for quantifying uric acid levels in point-of-care applications, particularly in resource-limited settings.

Metformin (MET) is an oral antidiabetic drug widely used as the primary treatment for type 2 diabetes mellitus (T2DM). While various spectrophotometric assays exist for determining MET in pharmaceutical formulations, they often have limited throughput for quality control purposes. This study describes the validation of a 96-microwell plate spectrophotometer method using charge-transfer complexes (CTCs) with chloranilic acid (CLA) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) for the quality control and detected of MET. This reaction was carried out in 96-microwell plates, and the absorbance of the colored complexes of CLA and DDQ were measured at 530 nm and 460 nm, respectively, using an absorbance microplate reader. This study aims to identify and quantify the use of a 96-microwell plate spectrophotometer analytical technique for assessing complicated formulations. The method was successfully used for the quantification of MET in the tablet dosage form. The results showed good correlation coefficients (0.996 and 0.997) with CLA and DDQ, respectively. The present method showed high precision with RSD % not exceeding 2.17%. The accuracy of the method was obtained by recovery percentage, with percentage values less than ±5%. The Analytical Greenness Metric (AGREE) was used to evaluate greenness of the assays. The result show that the microwell assay method is greenness and suitable for handling large samples on a daily used with high throughput analysis. The use of the 96-microwell-plate method is superior to the existing method in terms of simplicity of the procedure, the low economic cost, and its consumption of low amounts of reagents and organic ethanol solvent, making it an environmentally friendly method. Therefore, these advantages make them suitable and rapid alternatives method to current methods for routine metformin analysis in quality control laboratories.