Xanthine oxidoreductase (XOR), the key enzyme catalyzing purine to produce uric acid, including two subtypes, xanthine dehydrogenase (XDH) and xanthine oxidase (XO), respectively, in vivo. Usually, XDH and XO can transform to each other. In this study, based on the principle that the subtype XO or XDH uses different electron acceptors, the methods for the measuring the activities of bovine milk XOR (pure enzyme) and its subtypes were established. The optimal concentrations of substrate xanthine (50 μmol·L^-1) and electron acceptor NAD⁺ (50 μmol·L^-1), pH value (7.80) were investigated. The ranges of the XOR, XO, XDH activity which could be determined were 0.97-17.5 U·L^-1, 1-9 U·L^-1, and 66-1 191 mU·L^-1, respectively. Furthermore, the methods for determining the activities of XOR and its subtypes in mouse liver were established. The preparation of liver samples, the optimal concentrations of xanthine (100 μmol·L^-1) and NAD⁺ (100 μmol·L^-1) were researched. And the activity ranges of XOR, XO and XDH in mouse liver which could be determined were 0.67-3.98, 0.19-1.08, and 0.52-3.55 U·gprot^-1, respectively. With the methods above, the effects of classic XOR inhibitor allopurinal (Allo) on XOR, XO and XDH from both milk and mouse liver were determined. All animal experiments have been approved by the Animal Experimental Center, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College (00003346). This study established new methods for the determination of XOR and its subtypes activity in pure enzyme system and in mouse liver, respectively, which were accurate and convenient. It laid the experimental foundation for exploring the different pathophysiological effects of XOR in the body and developing new XOR inhibitors.

This study focuses on the microbial quality control of the Chinese herbal decoction pieces. In view of the shortcomings of traditional culture methods such as slow detection speed and inability to detect unculturable microorganisms, a new method based on ATP bioluminescence technology combined with statistical analysis methods was established to rapidly predict and quantitatively detect the total aerobic microbial count (TAMC) and total yeast and mold count (TYMC) contaminated Bupleurum chinense DC. decoction pieces. Based on the optimized ATP bioluminesence detection system, accurate detection of pure bacterial solution of Escherichia coli, Bacillus subtilis and Staphylococcus aureus can be achieved, with detection limits of 47.86, 89.13 and 1 862.09 CFU·mL^-1, respectively. The detection time was 6.5 h, and the detection cost was as low as 2 yuan/time. The upper and lower warning limits of TAMC were determined by the misjudgment rates of 10% and 20%, respectively. And the warning limit of TYMC was determined by the misjudgment rate of 20%. The proposed crossing method could quickly predict the amount of microbial contamination in Bupleurum chinense DC. decoction pieces. The constructed partial least squares regression (PLSR) model could accurately quantify the quantity of microbial contamination in Bupleurum chinense DC. decoction pieces. The optimal PLSR prediction model for TAMC had a correction coefficient (R²) of 0.826, a root mean square error of correction set (RMSE_E) of 0.468 and a root mean square error of cross-validation set (RMSE_CV) of 0.465. The R², RMSE_E and RMSE_CV in the prediction model of TYMC were 0.778, 0.543 and 0.541, respectively. The aim of this study is to establish a kind of rapid detection method and prediction models for the microbial limit of traditional Chinese medicine and Chinese herbal decoction pieces, and to provide a more convenient and sensitive detection technology for the microbial quality process control of traditional Chinese medicine products.

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.

Seven compounds were isolated from fermentation extract of cave-derived Metarhizium anisopliae NHC-M3-2 by silica gel, semi-preparative HPLC and other chromatographic methods. Their structures were elucidated by UV, IR, MS and NMR methods as 2,3-dehydroindigotide G (1), (-)-regiolone (2), naphtho-γ-pyrone (3), indigotide G (4), indigotide B (5) destruxin A (6) and destruxin B (7). Compound 1 is a new glycoside naphthopyranone compound. The anti-hepatitis B virus (HBV) activity of these compounds was evaluated. The EC₅₀ and CC₅₀ of compound 3 against HBV were 4.5 μmol·L^-1 and 92.3 μmol·L^-1, respectively. This is the first report of the antiviral activity of compound 3.

There is still a serious challenge of the measurement of critical quality attributes (CQAs) related to clinical efficacy for Chinese materia medica manufacturing. To overcome this challenge, an integrated strategy of biosensor and ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was proposed using Tongren niuhuang qingxin pills as a trial. Firstly, an original biosensor was created using a semiconductor chip material high electron mobility transistor (HEMT) as the transducer and the macrophage migration inhibitory factor (MIF) as the identification element. By this MIF-HEMT biosensor, the efficacy on stoke of different components from Tongren niuhuang qingxin pills was measured. It was clear that all three components of Tongren niuhuang qingxin pills had strong therapeutic effects on stroke, especially the section A, the K_D of which reached to 8.722×10^-10 g·mL^-1. Furthermore, MIF-HEMT biosensor integrated UPLC-MS/MS was introduced to identify the efficacy CQAs of different components of Tongren niuhuang qingxin pills. As a result, 19 potential CQAs, such as albiforin, paeoniflorin, and prim-O-glucosylcimifugin, were measured as the efficacy CQAs of Tongren niuhuang qingxin pills on stroke treatment by MIF. These results provided vital measurement techniques and methodological guidance for the CQAs study of Tongren niuhuang qingxin pills intervention in MIF-induced stroke treatment. This also provided an essential guideline for the efficient utilization and quality control measurement of high-quality classical recipes.

Analyze the changes in gene expression profiles during the process of Panax ginseng seed dormancy release, and screen for differential genes, providing a basis for analyzing the mechanism of P. ginseng seed dormancy release. Comparative transcriptome analysis was conducted by using RNA-Seq sequencing technology in P. ginseng seeds stored at different low temperature. A total of 80.97 Gb of Raw reads and 80.19 Gb of Clean reads were obtained from the transcriptome. Principal component analysis and correlation analysis showed that there were significant differences in gene expression patterns at different developmental stages. Upset results showed that 46 248 unigenes were co-expressed in four stages, and 414, 445, 400 and 389 unigenes were specifically expressed in 0, 8, 14 and 28 days, respectively. Gene Ontology functional annotation showed that the differentially expressed genes were mainly involved in nsaturated fatty acid biosynthetic process, nuclear body and oxidoreductase activity. Encyclopedia of Genes and Genomes metabolic pathway showed that differentially expressed genes were mainly involved in peroxisome, mitogen-activated protein kinase signaling pathway-plant, plant hormone signal transduction, ribosome, biosynthesis of unsaturated fatty acid, circadian rhythm-plant and other metabolic pathways. In the process of P. ginseng seed dormancy release, multiple biological processes, such as unsaturated fatty acid biosynthesis and plant hormone signal transduction, are required to coordinate regulation, which constitutes a complex dormancy release regulation network. Transcriptome analysis and differential gene screening of P. ginseng seeds at different sand storage time laid a foundation for the analysis of P. ginseng seed dormancy release mechanism and molecular breeding.

To discover new structural hits, based on the important role of pyrazole ring and fragment of pyridinone carboxylic acid in drug design, novel title pyrazolo[3,4-b]pyridine-4-one-5-carboxylic acid derivatives (10a-10p) were designed and synthesized, the structures were confirmed by spectral data and elemental analyses. The antibacterial and antitumor activities were evaluated by the measured minimum inhibitory concentration (MIC) values against the tested four strains and half inhibitory concentration (IC₅₀) values against the tested four cancer cells, respectively. The results displayed markedly poor antibacterial activity and observably potent antitumor activity. In particularly, the title difluorophenyl (10d, 10e, 10f), pyridyl (10j), ethyl (10k) and cycloproyl (10l) compounds exhibited comparable activity against Capan-1 and A549 cells to that of the comparison doxorubicin. Thus, pyrazolo[3,4-b]pyridine-4-one-5-carboxylic acid derivatives as promising antitumor hits need to be developed.

Artificial intelligence-aided drug discovery (AIDD) is a new version of computer-aided drug discovery (CADD). AIDD is featured in significantly promoting the performance of conventional CADD. AI markedly enhances the learning ability of CADD. In the 1960s, CADD was established from conventional QSAR approaches, which mainly used regression approaches to derive substructure-activity relationship for compounds with a common scaffold, and guide drug molecular design, figure out the binding features of drugs, and identify potential drug targets. Since the 1990s, structural biology has provided three-dimensional structures of drug targets, enabling drug discovery based on target structure (SBDD), fragment-based drug discovery (FBDD), and structure-based virtual screening (SBVS) with CADD approaches. In the past 30 years, many first in class (FIC) and best in class (BIC) drugs were discovered with CADD. Now, AIDD will further revolutionize CADD by reducing human interventions and mining big chemical and biological data. It is expected that AIDD will significantly enhance the abilities of CADD, virtual screening and drug target identification. This article tries to provide perspectives of CADD and AIDD in medicinal chemistry with case studies.

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.

Currently, the resistance of first-line anti-tuberculosis drugs has made the prevention and treatment of tuberculosis increasingly difficult, posing a serious threat to global public health. Several studies have shown that efflux pumps are one of the important causes for bacteria to develop multi-drug resistance and extremely-drug resistance, and efflux pump inhibitors can inhibit the efflux of antibacterial drugs, thereby reducing bacterial drug resistance. Numerous natural products and synthetic compounds have been reported to possess efflux pump inhibitory activity, but they have not been applied in clinical settings because of their toxicity, pharmacokinetic properties, etc. Therefore, we summarized the efflux pump inhibitory activity, antimicrobial activity, and structure-activity relationships of reported efflux pump inhibitors against Mycobacterium tuberculosis in recent years, providing references for the development of new efflux pump inhibitors with better activity and lower toxicity.