Latest ArticlesTwo compounds were isolated from 95% ethanol extract of the gum resin of Boswellia carterii by silica gel column chromatography (CC) and high-performance liquid chromatography (HPLC). Their structures were identified with IR, UV, NMR and HR-ESI-MS spectroscopic data as 7α-hydroxy-3, 11-dioxo- tirucalla-8, 24-dien-21-oic acid (1) and 21β-hydroxy-3-acetyl-11-keto-β-boswellic acid (2). In addition, their absolute configurations were also identified by ECD calculations. Among them, compound 1 is a new compound and the absolute configuration of compound 2 is confirmed by ECD calculation for the first time.
Two new labdane diterpenoids were isolated from 95% ethanol extract of the leaves of Callicarpa formosana Rolfe by using silica gel column, MCI column, ODS column and HPLC. Their structures were elucidated by HR-ESI-MS, NMR and ECD spectral data. All of them are new compounds, named 13E-6β-hydroxylabda-8(17), 13-dien-15-oic acid (1) and 13E-7α-hydroxylabda-8(17), 13-dien-15-oic acid (2). Compounds 1 and 2 were tested for antioxidant activity, and none of them had obvious activity.
The purpose of this study was to investigate the effect of isorhyncophylline on hippocampal endogenous metabolites in spontaneously hypertensive rats (SHR) by 1H NMR metabolomics and molecular docking. Twelve SHR were randomly divided into a model group and a treatment group. Six Wistar-Kyoto rats were selected as a control group. The rats in the treatment group were administered isorhyncophylline (0.3 mg·kg-1) while the rats in the other two groups were treated with the same amount of sterilized saline solution. Animal experiment was authorized by the Ethics Committee of Shandong University of Traditional Chinese Medicine (No. SDUTCM20210721002). Hippocampal tissues were removed after administration for 8 weeks and assayed by 1H NMR based metabolomics technology combined with a pattern recognition method to find characteristic metabolites, and the metabolic targets were retrieved from the Kyoto Encyclopedia of Genes and Genomes database. Molecular docking technology was used to evaluate binding of isorhyncophylline to the core targets. The results of a principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA) showed a clear cluster of samples among three groups. There were seven differentially altered metabolites, and glucose metabolism and glutamate metabolism were the principal related pathways. Molecular docking indicated that isorhyncophylline had good binding properties with nine key candidate target proteins. According to the above research results, isorhyncophylline can influence energy metabolism and glutamate metabolism in the hippocampus.
A method to measure the antibody-dependent cell-mediated phagocytosis (ADCP) potency of anti-CD38 mAb was developed based on design of experiment (DoE) with a Jurkat/NFAT/CD32a-FcεRIγ transgenic cell line as the effector cell, the Daudi cell line as the target cells, and luciferase as the detection system. The DoE method was used for optimization of experimental parameters and methodological validation. The results show that anti-CD38 mAb exhibits a dose-response relationship with the following four-parameter equation: y = (A - D) / [1 + (x / C)B] + D. Several experimental parameters were optimized by statistical experimental design and determined as follows: the working concentration of anti-CD38 mAb was 800-20.81 ng·mL-1, the density of the target cells was 7.5×104 per well, and the density of effector cells was 2.5×104 per well, with an induction time of 6 h. The method showed good specificity. The recovery rate for samples from 5 different groups showed that the relative potencies of anti-CD38 mAb were (59.97 ± 4.74) %, (82.44 ± 5.15) %, (110.69 ± 11.71) %, (129.23 ± 5.22)% and (162.15 ± 3.66) %. The recoveries ranged from 103% to 120% and the RSDs of the above results were all less than 11%. The linear detection range was 50%-150%. Based on DoE design, this method for measuring ADCP potency of anti-CD38 mAb was optimized and validated with good specificity, repeatability and accuracy. This method can be used for evaluation of ADCP biological activity of anti-CD38 mAbs.
Probe electrospray ionization (PESI) is one of the typical types of ambient ionization technology, but its application in quantitative analysis is limited due to its poor sampling stability. Previously, we developed a new micro-pen electrospray ionization tandem mass spectrometry (μPen-ESI-MS/MS) method based on PESI. In this study, a μPen-ESI-MS/MS method to measure testosterone and dextromethorphan in liver microsome samples was developed and validated to further applicate in evaluating drug metabolism stability and CYP450 enzyme activity. A μPen-ESI-MS/MS method for detecting the CYP3A4 substrate testosterone and CYP2D6 substrate dextromethorphan in the liver microsome incubation system were developed, and the linearity, precision and accuracy of the method was validated. The validated method was further used to detect the metabolic stability of testosterone in the liver microsome incubation system. The results showed that the μPen-ESI-MS/MS had high efficiency with 0.3 min spraying time of each sample. The standard curve of the testosterone and dextromethorphan has good linearity (R2 > 0.99), the intra- and inter-batch accuracy of testosterone and dextromethorphan was 95.9%-109.3% and 90.5%-107.3%, respectively; the intra- and inter-batch precision was acceptable with RSD values of 2.4%-13.5% and 3.4%-12.1%. The half-lives of testosterone and dextromethorphan in the liver microsome incubation system were 12 min and 14 min, respectively. This study provided a rapid and sensitive μPen-ESI-MS/MS method for the assay of testosterone and dextromethorphan in liver microsome samples, and provided a new strategy for the evaluation of drug metabolism stability and CYP3A4/CYP2D6 activity.
The joint application of traditional Chinese medicine injection containing chlorogenic acid (CA) and cefotaxime sodium (CS) is sometimes appeared in clinical practice, but the scientific basis of drug molecular compatibility is still weak. This study proposes a sequential analysis strategy based on isothermal titration calorimetry (ITC), cold-spray ionization mass spectrometry (CSI-MS) and antibacterial activity test to evaluate the molecular interactions between CA and CS. The results of ITC experiments showed that the Gibbs free energy ΔG < 0 and it was driven by enthalpy change when CA titrated CS, suggesting CA could spontaneously chemically react with CS. Subsequently, the parent ions (m/z 808.143 5) of binding molecular of CA and CS was detected by CSI-MS, indicating CA could chemically bond with CS. Furtherly, the antibacterial experiments found the antibacterial ability of CS against Klebsiella pneumonia was significantly reduced (P < 0.01) by CA in mixed solution. Finally, molecular docking technology showed CA and CS have a common target of penicillin binding protein 3 (PBP3), suggesting that the phenomenon of CA reduced the antibacterial ability of CS may be related to the competitive binding of two components with PBP3. Our studies have shown that CA could spontaneously chemically bond to CS and reduced its antibacterial ability, providing scientific data for molecular interaction evaluation of CA and CS.
Da Chaihu decoction is a classic prescription for the treatment of cholecystitis that is widely used in clinical practice, and has a definite curative effect. However, due to its diverse components and complex functions, the traditional indexes fail to capture its overall efficacy. Therefore, this study analyzed and predicted the quality markers (Q-markers) of Da Chaihu decoction based on specific chromatogram and network pharmacology to provide a reference for the comprehensive control of the quality. The study obtained 35 potential practical components of Da Chaihu decoction through virtual screening. The specific chromatogram of 15 batches of Da Chaihu decoction was established by HPLC-DAD with neohesperidin as a reference. Compared with the chromatographic peaks and the reference substance, the chemical components were assigned to predict the nine components of albiflorin, paeoniflorin, naringin, hesperidin, neohesperidin, baicalin, wogonoside, saikosaponin b2, saikosaponin b1 as Q-markers of Da Chaihu decoction. Finally, the network of the "components-key targets-signal pathways-biological processes" was constructed by network pharmacology to explore the mechanism of Da Chaihu decoction in treating cholecystitis to clarify the accuracy of Q-markers. The results indicated that potential Q-markers could act on multiple targets to regulate inflammatory and metabolism, and then combine to treat cholecystitis. Q-markers could combine with the pharmacologic action of Da Chaihu decoction, which could elucidate the overall efficacy of Da Chaihu decoction. This study explored the Q-markers of Da Chaihu decoction combined with the specific chromatogram and network pharmacology, which provided a basis for the quality control and evaluation of Da Chaihu decoction.
Solid dispersion, a dispersion system in which drug molecules are highly dispersed in carrier materials, has been commonly used to improve the solubility and dissolution rate of poorly soluble drugs. The miscibility between drug and carrier is crucial to improve the dissolution performance and stability of solid dispersion. Therefore, the selection of carrier types and the optimization of drug loading are very important. In the current study, the solubility parameter method and Flory-Huggins theory were used to predict the miscibility between olaparib (OLP) and different carriers (VA64, Soluplus, Plasdone S630 and Kollidon K29/32). Besides, the carrier material with good miscibility was experimentally screened by differential scanning calorimetry (DSC). The optimum of drug-carrier ratio was further performed based on the miscibility phase diagram of drug and carrier. Theoretical calculation and experimental evaluation showed that the miscibility of OLP and VA64 was the best, and the drug loading of 30% could meet the requirements of large drug loading and physical stability. Polarizing light microscope, X-ray powder diffraction, DSC and laser confocal Raman spectroscopy exhibited that OLP was amorphous form in the solid dispersion system. Powder dissolution test demonstrated that the solid dispersion showed significantly enhanced dissolution rate in comparison to crystalline OLP. In this study, theoretical calculation and experimental evaluation were used to screen the types of carriers and optimize the drug loading, which provides an efficient strategy for the selection of carrier and the amount used in solid dispersion.
Rhei Radix et Rhizoma is one of the most used medicinal materials in China. Its original species are Rheum palmatum, Rh. tanguticum, and Rh. officinale. Rhei Radix et Rhizoma derived from different original species are significantly different in their active ingredients and pharmacological effects. To develop an accurate, rapid, and specific identification method, we obtained the chloroplast genomes of the three original species by Illumina Novaseq sequencing. We designed specific DNA barcodes from the hypervariable regions, which can accurately identify the three original species. The experimental results showed that the total length of the chloroplast genomes of Rh. tanguticum, Rh. officinale and Rh. palmatum were 161 039 bp, 161 093 bp, and 161 136 bp, respectively. All the three genomes were represented as typical quadripartite structures. A total of 131 genes, including 86 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes were identified from each chloroplast genome. Five pairs of primers based on the hypervariable regions were designed to efficiently amplify 42 samples. Results confirmed that five hypervariable regions, rps16-trnQ, psaA-ycf3, psbE-petL, ndhF-rpl32, and trnT-trnL, can be used as specific DNA barcodes for the identification of Rh. tanguticum, Rh. officinale, and Rh. palmatum. These results provided genetic information for further species identification of Rhei Radix et Rhizoma, and improve the safety of this clinical medication as well as standardize the market for Rhei Radix et Rhizoma.
MYB transcription factors, one of the largest transcription factor families in plants, play an important role in signal transduction, plant growth and plant resistance. In this study a full-length cDNA of the PnMYB1R1 gene was cloned from Panax notoginseng. Sequence analysis, prokaryotic expression and purification, subcellular location, transcriptional activity analysis, tissue-specific analysis and expression analysis under different abiotic stresses was performed. The open reading frame (ORF) of PnMYB1R gene was 738 bp, encoding a protein of 245 amino acids with a predicted molecular mass (MW) of 27.0 kD. The sequence analysis and polygenetic analysis indicated that the PnMYB1R1 protein contains a conserved R3 domain, belonging to TRF-like protein in 1R-MYB-type transcription factors. The recombinant PnMYB1R1 protein was expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-PnMYB1R1 and was purified. Subcellular localization analysis showed that PnMYB1R1 was localized in the nucleus. Transcriptional activity analysis indicated that the PnMYB1R1 transcription factor has transcriptional activation activity. Expression analysis indicated that PnMYB1R1 was primarily expressed in roots, followed by stems and leaves, and then rootlets. The expression level of PnMYB1R1 in root, stems, leaves and rootlets was influenced by salt, low temperature and drought treatment, while the abundance of PnMYB1R1 was significantly induced by salt stress in these tissues. These results provide valuable insights into the role of 1R-MYB transcription factors in plant defense.