Latest ArticlesA simulating method for dripping process of Ginkgo biloba leaf dripping pills based on computational fluid dynamics was constructed. Ginkgo biloba leaf dripping pills was explored as the experimental subject to simulate the dripping process based on FLOW-3D software. The dripping process was simulated through the derivation of the governing equations, the selection of the models, and simulation parameters. Firstly, the droplet morphologies and drop speeds under different liquid viscosity were simulated. It was found that with the increase of the liquid viscosity, the drop speed decreased and the difficulty of droplet preparation gradually increased. The simulation results were consistent with the experiment results. Secondly, the droplet morphologies at different drop speeds were investigated and verified by experiments. It was found that the simulation results had a good correlation with the experiment results. The results shown that the viscosity of the liquid was the critical material attribute, and the drop speed was the critical process parameter, according to the droplet morphology. The establishment of the simulation method can deepen the understanding of the dripping process and provide a reference for the selection of raw materials and process parameters.
Sophorae Flavescentis Radix is the dried root of Sophora flavescens Ait. and Sophorae Tonkinensis Radix et Rhizoma is the dried root and rhizome of Sophora tonkinensis Gagnep. The two drugs are both from the same genus Sophora, having similar and different compositions and efficacies, however, their differences are not fully demonstrated in current standard. In this study, the high-performance thin-layer chromatography with multi-dimensional and multi-level features combined with electric spray mass spectrometry (HPTLC-ESI-MS) was used to discover and identify the characteristic zones in extracts of Sophorae Flavescentis Radix and Sophorae Tonkinensis Radix et Rhizoma, after optimizing the preparation method of the test solution and chromatographic parameters. As a result, 17 main characteristic zones were found on HPTLC chromatograms of Sophorae Flavescentis Radix and Sophorae Tonkinensis Radix et Rhizoma, among them, besides 3 known chemicals, another 12 unknown components were identified by HPTLC-ESI-MS, they are 1 alkaloid and 11 flavonoids. The identification results were verified by the reference standards partially and nuclear magnetic resonance spectra after guided-isolation. Finally, a unified HPTLC specific identification method with different markers was established to identify Sophorae Flavescentis Radix and Sophorae Tonkinensis Radix et Rhizoma simultaneously. Thanks to abundant chemical information provided when using diverse polarity mobile phases and derivatization reagents, the HPTLC technology offers a convenient strategy for discovery, quality evaluation, and identification of target chemicals when connecting with mass spectrometry.
The Ca2+-activated monovalent cation selective transient receptor potential melastatin 4 (TRPM4) channel expressed in pancreatic β-cells is implicated in the β-cell function and insulin secretion, but how pharmacological function of TRPM4 channel affects membrane excitability of β-cells remains largely unknown. Here, we report that pharmacological inhibition of TRPM4 by specific inhibitor 9-phenanthrol attenuates electrical activities of pancreatic β-cells. In whole-cell current clamp recordings, 9-phenanthrol results in inhibition of action potential frequency induced by tolbutamide of the INS-1 pancreatic β-cells in a dose-dependent manner with an IC50 value of 14.99 ± 7.93 μmol·L-1. Similarly, 9-phenanthrol also inhibited action potential firing in INS-1 cells stimulated by current injection. Further recordings of β-cells demonstrate the significant inhibitory effects on action potential peak and action potential amplitude by 9-phenanthrol. Taken together, our results show the involvement of TRPM4 channel function in pancreatic β-cells depolarization and action potential, it provides pharmacological experimental methods and theoretical support for the study of TRPM4 channel in pancreatic β-cells.
The polymorphism and thermostability of nirmatrelvir, the main antiviral component of the oral COVID-19 treatment drug, were studied. Four polymorphs of nirmatrelvir were prepared by recrystallization methods. Among them, Form 1 and nirmatrelvir methyl tert-butyl ether solvate (Form 2) had been reported in the literature, while nirmatrelvir isobutyl acetate solvate (NMTW-IBAC) and nirmatrelvir ethyl acetate solvate (NMTW-EA) are two new solvates. The crystal structures were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The thermostability of polymorphism and crystalline transformation were also investigated by combining Hirshfeld surface analysis and interaction energy analysis. The results showed that nirmatrelvir Form 1 belongs orthorhombic crystal system with the space group P212121 and one nirmatrelvir molecule included in the asymmetric unit, which has the same crystal structure as nirmatrelvir Form 4 reported in the literature. Owing to its larger thermal expansion, the differences in crystallographic parameters obtained at different temperatures were found between Form 1 and Form 4. Three solvates of nirmatrelvir belonged to the iso-structural with monoclinic crystal system and the space group P21, in which the asymmetric unit contains one nirmatrelvir molecule and one solvent molecule. The thermal analysis results showed that nirmatrelvir Form 1 was a solvent-free crystal form with the best thermal stability and the strongest intermolecular hydrogen bonding. Among the three solvates, NMTW-EA has the worst thermal stability and the weakest hydrogen bonding interaction between the nirmatrelvir molecule and the solvent molecule. The energy framework of nirmatrelvir solvates showed that the closer the arrangement between solvent and nirmatrelvir molecules, the greater the total interaction energy between solvent and nirmatrelvir molecules. The phase transition studies of the three solvates showed that NMTW-IBAC and NMTW-EA were transformed into amorphous after desolvation, respectively, while Form 2 undergoes oiling during desolvation. The research provides theoretical guidance for the analysis, identification and quality control of nirmatrelvir polymorphs.
Aiming at the hysteresis and destructiveness of off-line static detection of critical quality attribute of the moisture content of the raw material unit of the traditional Chinese medicine manufacturing process, honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis were used as the research carriers, and the drying method was used to measure the moisture content as a reference value. The moving stage was used to simulate the movement process of samples on the conveyor belt in the actual on-site production process, and near-infrared (NIR) spectra were collected, combined with machine learning, to establish NIR on-site dynamic detection model of moisture content in multi-variety honey-processed Chinese herbal slice. The results show that the second derivative method is used to preprocess the spectrum. The number of decision trees (ntree), the number of random features (max feature), and the minimum number of samples for generating leaf nodes (node size) are selected: 46, 76, and 8, respectively. The quantitative analysis model of moisture content has the best effect. The prediction coefficient of determination (the prediction coefficient of determination, Rpre2) and the root mean square error of prediction (root mean square error of prediction, RMSEP) of the model were 0.903 2 and 0.330 2, respectively. The NIR quantitative model for the moisture content of multi-variety honey-processed Chinese herbal slice established in this study has good predictive performance, and can achieve rapid, accurate and non-destructive quantitative analysis of the moisture content of honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis at the same time, and provides a method for determining the moisture content of honey-processed Chinese herbal slice of the raw material unit of the traditional Chinese medicine manufacturing process.
Pulmonary fibrosis is an interstitial lung disease characterized by inflammatory injury and tissue structure destruction. Currently, there is a lack of effective therapeutic drugs for pulmonary fibrosis, and the mechanism is still unknown. Therefore, it is urgent to seek new targets for effective drugs. In pulmonary fibrosis, the level of autotaxin (ATX) in bronchoalveolar lavage fluid increases and stimulates the production of lysophosphatidic acid (LPA). The involvement of LPA receptors in activating a variety of G-protein-mediated signal transduction pathways leads to a range of related physiological effects, including pro-inflammatory signaling in epithelial cells, activation of transforming growth factor signaling, and stimulation of fibroblast accumulation. LPA receptor antagonists and ATX inhibitors have been concerned as new targets for pulmonary fiber therapy, and currently related drugs have entered clinical trials. In this paper, the pathophysiological effects of LPA and ATX in pulmonary fibrosis disease and related drug development progress were reviewed to provide reference information of new drug development for pulmonary fibrosis based on the ATX-LPA axis.
The modernization and development of traditional Chinese medicine has led to higher standards for the quality of traditional Chinese medicine products. The extraction process is a crucial component of traditional Chinese medicine production, and it directly impacts the final quality of the product. However, the currently relied upon methods for quality assurance of the extraction process, such as simple wet chemical analysis, have several limitations, including time consumption and labor intensity, and do not offer precise control of the extraction process. As a result, there is significant value in incorporating near-infrared spectroscopy (NIRS) in the production process of traditional Chinese medicine to improve the quality control of the final products. In this study, we focused on the extraction process of Xiao'er Xiaoji Zhike oral liquid (XXZOL), using near-infrared spectra collected by both a Fourier transform near-infrared spectrometer and a portable near-infrared spectrometer. We used the concentration of synephrine, a quality control index component specified by the pharmacopoeia, to achieve rapid and accurate detection in the extraction process. Moreover, we developed a model transfer method to facilitate the transfer of models between the two types of near-infrared spectrometers (analytical grade and portable), thus resolving the low resolution, poor performance, and insufficient prediction accuracy issues of portable instruments. Our findings enable the rapid screening and quality analysis of XXZOL onsite, which is significant for quality monitoring during the traditional Chinese medicine production process.
Hepatitis B virus (HBV) represents a significant global public health challenge. Despite the availability of several approved drugs for hepatitis B treatment, the persistence of covalently closed circular DNA (cccDNA) renders HBV eradication elusive, thereby leading to disease relapse after drug withdrawal. This paper reviews the regulatory mechanisms of cccDNA formation, transcription and replication, and summarizes the research progress of related small molecule regulators from the perspective of medicinal chemistry.
The aim of this study was to investigate the role and mechanism of terpinen-4-ol (T4O) on high glucose (HG) -induced calcification in vascular smooth muscle cell (VSMC). To investigate the role of T4O on HG-induced calcium deposition, osteogenic phenotypic transformation and mitochondrial dynamics in VSMC, Mdivi-1, a mitochondrial dynamin-related protein 1 (Drp-1) inhibitor, was used to analyze the correlation between mitochondrial dynamics and VSMC calcification and the role of T4O. Alizarin red S staining was used to observe calcium salt deposition and flow cytometry to detect intracellular Ca2+ content; Western blot and immunofluorescence were used to detect the expression of phenotypic switching-related markers α-smooth muscle actin (α-SMA), bone morphogenetic protein 2 (BMP2) and Runt related transcription factor 2 (Runx2), and mitochondrial dynamics-related markers mitofusin 1 (MFN1), mitofusin 2 (MFN2) and Drp-1. The results showed that low and high doses of T4O could inhibit HG-induced down-regulation of α-SMA, MFN1 and MFN2 expression levels, and up-regulation of BMP2, Runx2 and Drp-1 expression levels, reduce intracellular Ca2+ content and calcium salt deposition, and effectively inhibit HG-induced VSMC calcification and mitochondrial dynamics disorders. The T4O group, Mdivi-1 group and T4O+Mdivi-1 group were able to up-regulate the expression levels of HG-induced α-SMA, MFN1 and MFN2, down-regulate the protein expression levels of BMP2, Runx2 and Drp-1, and inhibit calcium salt deposition, and there was no significant difference between the above indexes in the T4O and T4O+Mdivi-1 groups. The above findings suggest that T4O can inhibit the expression level of Drp-1, regulate the disturbance of mitochondrial dynamics, and suppress HG-induced VSMC calcification.
An LC-MS method with natural isotope abundance correction and a 1H NMR relative quantitative method were established to determine the deuterium incorporation of donafenib tosilate, a new deuterated drug molecule. First, the peak areas of isotopic impurities (non-deuterated and incompletely deuterated impurities) and deuterated drug were recorded through the single ion monitoring (SIM) mode of the established LC-MS method and then corrected in terms of the natural isotope abundance offered by ChemDraw soft, removing the nature isotope interference from 13C, 37Cl, etc. The corrected areas were subsequently used to calculate mol% of isotopologues (D0, D1, D2, D3) and Atom% D, namely, deuterium incorporation. In addition, a 1H qNMR experiment was conducted with the aromatic proton at δ 8.63 and the residual proton of isotopic impurities at δ 2.79 as quantitative peaks. The mixture of DMSO-d6 and D2O (10∶1) was employed as the solvent to change the spin-coupling between the residual proton and active hydrogen so that the residual proton could be measured as the single peak, and the sensitivity was greatly improved. The acquisition parameters were also optimized, and Atom% 1H and the deuterium incorporation were then calculated. The two methods were applied to samples of three commercial batches, and the testing results were almost consistent. Both methods proved accurate, sensitive, fast and independent of standard substances and accurate weighing, which could be applied to the determination of the deuterium incorporation of donafenib tosilate and provide a reference for other deuterated drugs.