Latest ArticlesA quantitative analytical method based on HPLC coupled with the charged aerosol detector (CAD) for quantitative analysis of multi-components with a single marker (QAMS) was established for simultaneous determinations of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-O-β-D-glucoside, formononetin and 7, 2'-dihydroxy-3', 4'-dimethoxyisoflavan in Astragalus membranaceus. The separation was performed on an Agilent SB-C18 (150 mm×4.6 mm, 3.5 μm), with gradient elution using the mobile phase consisting of 0.05% formic acid solution and 0.05% formic acid acetonitrile at the flow rate of 1.0 mL·min-1. The column temperature was 35 ℃, and the injection volume was 20 μL. For CAD, the drift tube temperature was at 50 ℃. The contents of six components in A. membranaceus were determined by both external standard method (ESM) and QAMS, and then were compared. The results showed that chromatographic peaks were separated well and the linear ranges of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7, 2'-dihydroxy-3', 4'-dimethoxyisoflavan were 0.113-2.250 mg·mL-1, 0.012-0.240 mg·mL-1, 0.004-0.080 mg·mL-1, 0.065-1.300 mg·mL-1, 0.005-0.100 mg·mL-1 and 0.007-0.150 mg·mL-1, respectively. The content ranges of astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7, 2'-dihydroxy-3', 4'-dimethoxyisoflavan were 0.306-0.922 mg·g-1, 0.053-0.183 mg·g-1, 0.015-0.092 mg·g-1, 0.069-0.823 mg·g-1, 0-0.098 mg·g-1 and 0.020-0.107 mg·g-1 in 20 batches of A. membranaceus, respectively. Using astragaloside Ⅱ as an internal reference, the relative correlation factors of astragaloside Ⅰ, astragaloside Ⅳ, calycosin-7-O-β-D-glucoside, formononetin, and 7, 2'-dihydroxy-3', 4'-dimethoxyisoflavan were calculated as 0.561, 0.835, 0.299, 0.796, and 0.799, respectively. The results were compared with those obtained by the external standard method to verify the feasibility, rationality and repeatability of QAMS method, and there was no significant difference in assay results between the two methods. In conclusion, the QAMS method is accurate and feasible, and could be used to determine the contents such as astragaloside Ⅰ, astragaloside Ⅱ, astragaloside Ⅳ, calycosin-7-glucoside, formononetin and 7, 2'-dihydroxy-3', 4'-dimethoxyisoflavan, and it can be used for quality control of A. membranaceus.
With high selectivity and potency, target protein degradation technology has recently emerged as a strategy for drug discovery and design. Proteolysis-targeting chimeras(PROTAC) function as inducers for the degradation of target proteins and are a research focus in drug development. Current research on PROTAC mainly revolves around the rational design of PROTAC molecules, the discovery of new E3 ubiquitin ligase ligands and improvement in drug targeting. In this review, we focus on the PROTAC linker and its effects on the generation of the E3 enzyme-PROTAC-target protein ternary complex from three standpoints: length, binding site and chemical properties. We discuss the influences of the linker on the efficacy and the selectivity of PROTAC molecules.
Bupleurum L.(Apiaceae) is an economically important genus, in which many species are of medicinal value. In this study, the complete plastid genomes(plastomes) of B. chinense DC. and B. boissieuanum H. Wolff were sequenced and their characteristics were investigated. Comparative and phylogenetic analyses were conducted with other published Bupleurum plastomes. The complete plastomes of B. chinense and B. boissieuanum were 155 458 and 155 800 bp in length, and both exhibited the typical quadripartite circular structure consisting of a large single copy region(LSC, 85 343 and 85 804 bp), a small single copy region(SSC, 17 495 and 17 410 bp), and a pair of inverted repeat regions(IRa/b, 26 310 and 26 293 bp), respectively. A total of 129 genes, including84 protein-coding genes, 37 transfer RNA(tRNA) genes, and eight ribosomal RNA(rRNA) genes were identified from each of the two plastomes. Repeat sequences detected were similar in types and distribution patterns, but the numbers were slightly different. Comparative analyses revealed that the Bupleurum plastomes were highly conserved in length, structure, the guanine and cytosine(GC) content, and gene content and order, both intraspecifically and interspecifically, and no obvious expansion or contraction of the inverted repeat regions occurred. Sequence variation was lower within the same species than among different species, noncoding sequences(including intergenic regions and introns) showed a higher divergence than the protein-coding sequences, and sequences in the LSC and SSC regions were more divergent than those in the IR regions. In addition, 11 sequences with higher nucleotide diversity among species were detected in the LSC and SSC regions. All studied Bupleurum species were inferred forming a monophyletic group with a 100% bootstrap value. Bupleurum chinense and B. boissieuanum were phylogenetically closest to B. commelynoideum and B. falcatum, separately, with all three B. chinense accessions clustered into a distinct clade. These results provide genetic information for further species identification, phylogenetic resolution, and will assist in exploration and utilization of medicinal Bupleurum species.
Drug use during pregnancy is unavoidable. Therefore, it is vitally important for medical workers to help pregnant women take drugs correctly to reduce the incidence of spontaneous abortion, premature birth, and low birth weight. In our study, drug screening model with induced pluripotent stem cells(iPSCs) was used to find some improper drugs which will result in woman's abortion. With 3D culture in vitro, iPSCs can form embryoid bodies(EBs) and cerebral organoids, which simulated in vitro development of early embryos, from inner cell mass to germ-layer differentiation. In the experiment, EBs were exposed to mifepristone(RU486), and three experimental groups were divided randomly. They were control group(without RU486), low-dose group(L-RU486, 10 μg·mL-1), and high-dose group(H-RU486, 20 μg·mL-1). After mifepristone exposure, EBs were observed at days 5, 8, and 11, including size of EB, cell apoptosis, and differentiation of germ layers, by using inverted optical microscope, TUNEL assay, and immunofluorescent staining. The results showed that through 3D culture, iPSCs could develop into embryoid bodies, neural rosettes, and finally cerebral organoids. After mifepristone exposure, EBs' sizes were decreased(P < 0.01); the levels of cell apoptosis in EBs were increased after mifepristone exposure(P < 0.01); the development of EBs' germ layer was affected. Mifepristone exposure could inhibit the proliferation of embryonic stem cells, reduce the differentiation of ectoderm(P < 0.01) and promote the development of mesoderm(P < 0.05).In conclusion, iPSCs can be used as a screening model for abortion drug, and EBs' diameter, cell apoptosis, and differentiation changes of the germ layers can serve as criteria of abortion drug screening.
Natural products and their derivatives are important components of anti-tumor drugs. Currently, anti-tumor drugs derived from natural products which are in clinical practice are mainly conventional cytotoxic or molecularly targeted drugs. Their application is limited by drug-related side effects and drug resistance. Recent studies have shown that anti-tumor natural products often act on multiple targets in tumor cells and in turn interfere with multiple processes in tumorigenesis and development. As tumor is a systemic disease induced by multiple factors, multi-targeted natural products possess unique potential in tumor therapy. However, the targets and mechanisms of the discovered multi-targeted antitumor natural products remain elusive, which limits their further development and application. This review summarized the research progress in the mechanism of action, target identification, and structure optimization of multi-targeted anti-tumor natural products exemplified by a few typical compounds. The research and development of these agents have also been proposed.
Compared with normal tissues and cells, the tumor microenvironment has significant differences.For example, glutathione-related metabolic enzymes and reactive oxygen species are highly expressed in different subcellular structures, resulting in an unbalanced redox state. Aiming at the specific redox state in tumor tissues and cells, a series of small molecule prodrug self-assembled nanoparticles can be designed and connected by intelligent response linkers including disulfide bonds, sulfide bonds, and selenium bonds, thioketal bonds, etc. The in vitro and in vivo efficiency and metabolic mode of these nanoparticles are related to the type of linker. This review will summarize the tumor redox microenvironment, the design of intelligent responsive small molecule prodrug nanoparticles, and the metabolic pathways of small molecule prodrug nanoparticles with different connecting linkers and their relationship with drug efficacy.
As a key gene in the regulation of long-chain fatty acid biosynthesis, 3-ketoacyl-CoA synthase (KCS) plays an important role in the growth and development of Coix lacryma-jobi L. In this study, the KCS gene was cloned from cDNA of Coix lachryma-Jobi L. and bioinformatics analysis was performed. Results showed that the full length KCS gene was 1 548 bp encoding 515 amino acids. Bioinformatics analysis indicated that the gene encoded a 58 608.12 Da protein with an isoelectric point of 9.20 containing two transmembrane helical structure domains and lacking a signal peptide, with a likely subcellular localization in main plastid membranes. The results of multiple sequence comparisons and evolutionary tree analysis revealed that KCS had three identical conserved sequences and was closely related to KCS from monocotyledons such as Sorghum bicolor, Zea mays, Setaria italica, Panicum miliaceum, Oryza brachyantha, Hordeum vulgare, Aegilops tauschii subsp. Tauschii. We speculated that the evolution of the gene was similar among these plants of the same family. In addition, gene expression analysis showed that the KCS gene was significantly different in Coix lacryma-jobi L. isolates having different lipid content. This work will facilitate further study of the regulatory mechanism of this enzyme in fatty acid synthesis.
(±)-Bicoryanhunine B(1), a new dimeric benzylisoquinoline alkaloid was isolated from the dried tubers of Corydalis yanhusuo by various chromatographic methods, including silica gel, Sephadex LH-20, reverse phase C18, and semi-preparative HPLC.Its structure was determined by spectroscopic methods, including UV, IR, ESI-MS, HR-ESI-MS and 1D/2D NMR.(±)-Bicoryanhunine B(1) was a moderate PD-1/PD-L1 interaction inhibitor with an IC50 value of 7.80±0.49 μmol·L-1.In addition, 1 exhibited potent inhibitory activities against LPS-induced NO production in RAW 264.7 macrophages with an IC50 value of 4.83 ± 2.21 μmol·L-1.
The therapeutic effect of tumor photodynamic therapy is severely limited by the hypoxic tumor microenvironment. Inhibiting tumor celloxygen consumption is a more effective way than increasing its oxygen supply to overcome the tumor hypoxia and enhance photodynamic therapy. To carry out this strategy, the supramolecular nanoparticles VER-ATO-SMN loaded with photosensitizer verteporfin(VER), oxygen-consuming inhibitor atovaquone(ATO), and stabilizer polyvinylpyrrolidone(PVP)-K30 were prepared by the nanoprecipitation method, and the optimal prescription was screened and optimized by single factor experiments. The results showed that the optimal prescription for VER-ATO-SMN was ATO∶VER(w/w) = 1∶1, PVP-K30 = 100 mg, N, N-dimethylformamide∶water(v/v) = 1∶10. The morphology, particle size, particle dispersion index and encapsulation efficiency of supramolecular nanoparticles were characterized. The VER-ATO-SMN showed a spherical morphology and was well dispersed. The hydrodynamic size of VER-ATO-SMN was 101.21 ± 4.30 nm as determined by dynamic light scattering(DLS). The encapsulation efficiencies of VER and ATO in VER-ATO-SMN prepared with the optimal prescription were 70.86% and 77.52%, respectively. The VER-ATO-SMN exhibited good laser stability and also showed high stability in conditions which simulated the physiological solution. Compared with free VER and VER liposome, VER-ATO-SMN performed enhanced therapeutic effect at the cell level. The mechanism was that VERATO-SMN could effectively incorporate into cells and improving the intracellular oxygen concentration by reducing the oxygen consumption of tumor cells could increase the amount of reactive oxygen species generated by VER mediated photodynamic therapy. The in vivo anticancer efficacy results of tumor-bearing mice suggested that VER-ATO-SMN could effectively inhibit the tumor growth or even completely eliminate the tumor. All animal experiments were performed in line with national regulations and approved by the Animal Experiments Ethical Committee of 900 Hospital of the Joint Logistics Team.
The interaction between platelets and tumor cells can not only promote the metastasis of malignant tumors, but also affect the formation of malignant tumor-related thrombus. When tumor cells enter the blood, they will immediately activate platelets to make them adhere to the surface of tumor cells, protecting tumor cells from blood flow shear force and immune system attack, thereby promoting tumor metastasis. At the same time, the massive adhesion of platelets may also lead to the formation of thrombus. In this article, we use the methods of ingenuity pathway analysis and literature integration to explore the mechanism of platelet-tumor cell interaction and potential drugs for the treatment of malignant tumor metastasis based on the platelet-tumor cell interaction. It provides a certain theoretical basis and clinical reference for the future development of new drugs targeting platelettumor cell interaction based on its mechanism of action.