195 results on '"Xin, Shan"'
Search Results
2. Optimization of a novel lipid extraction process from microalgae
- Author
-
Chao Wei, Xin Shan, Mengyun Wu, Xiaojie Ren, Yuanda Song, Qi Yan, and Xinhe Zhao
- Subjects
Science ,Liquid-Liquid Extraction ,Cell morphology ,Article ,chemistry.chemical_compound ,Acetone ,Microalgae ,Dichloromethane ,Methylene Chloride ,Multidisciplinary ,Chloroform ,Chromatography ,Extraction (chemistry) ,Water ,Lipids ,Solvent ,chemistry ,Isolation, separation and purification ,Microscopy, Electron, Scanning ,Solvents ,Medicine ,Water treatment ,Methanol ,Microbiology techniques - Abstract
Previous study found that the solvent extraction efficiency of lipid in microalgae could be greatly improved by washing algae cells before the second time extraction. Based on the "organic solvents–water–organic solvents" method, this research further studied the effect of four solvent systems (acetone, chloroform/methanol, chloroform/methanol/water, dichloromethane/methanol), two types of water treatment (vortex and ultrasonic), three water treatment time gradient (0 s, 30 s, 120 s) on the lipid extraction at three different microalgae growth stages (3rd day, 5th day, 9th day). The results show that the combination of water treatment type, treatment time and solvent is very important to the efficiency of lipid extraction. The total lipid extracted was generally increased by 10–30% after water treatment. Especially under the condition of 120 s vortex water treatment with dichloromethane/methanol as extraction solvent, the total lipid extracted increased by 61.14%. In addition, microalgae cells at different culture stages had different sensitivity to water treatment. In this study, under the combination of chloroform/methanol/water as extraction solvent and vortex water treatment for 120 s, the highest lipid yield was obtained on the ninth day of cell culture, which accounts 47.88% of the cell dry weight (478 mg/g cell dry weight). The changes of cell morphology and structure after water treatment were studied by scanning electron microscope, and it was found that water treatment could seriously destroy the cell membrane damaged by solvent, thus promoting the release of lipids. This study further optimizes the "solvent–water–solvent" lipid extraction method, which neither produces impurities nor damages the lipid quality, and can reduce the amount of organic solvent applied in the classical lipid extraction method with the same lipid yield, so it has a broad application prospect.
- Published
- 2021
3. Influenza Virus Precision Diagnosis and Continuous Purification Enabled by Neuraminidase-Resistant Glycopolymer-Coated Microbeads
- Author
-
Gefei Li, Xin-Shan Ye, Boyang Cheng, Wenxiao Ma, Demin Zhou, Juan Mo, and Shin Ichiro Shoda
- Subjects
Materials science ,viruses ,Glycopolymer ,Chromatography, Affinity ,Virus ,Madin Darby Canine Kidney Cells ,chemistry.chemical_compound ,Dogs ,Influenza A Virus, H1N1 Subtype ,Limit of Detection ,Polysaccharides ,Influenza, Human ,Animals ,Humans ,General Materials Science ,Surface plasmon resonance ,Infectivity ,biology ,Viral Vaccine ,Surface Plasmon Resonance ,Viral Load ,Virology ,Microspheres ,HEK293 Cells ,Carbohydrate Sequence ,chemistry ,Colloidal gold ,biology.protein ,Ultracentrifuge ,Neuraminidase - Abstract
Rapid diagnosis and vaccine development are critical to prevent the threat posed by viruses. However, rapid tests, such as colloidal gold assays, yield false-negative results due to the low quantities of viruses; moreover, conventional virus purification, including ultracentrifugation and nanofiltration, is multistep and time-consuming, which limits laboratory research and commercial development of viral vaccines. A rapid virus enrichment and purification technique will improve clinical diagnosis sensitivity and simplify vaccine production. Hence, we developed the surface-glycosylated microbeads (glycobeads) featuring chemically synthetic glycoclusters and reversible linkers to selectively capture the influenza virus. The surface plasmon resonance (SPR) evaluation indicated broad spectrum affinity of S-linked glycosides to various influenza viruses. The magnetic glycobeads were integrated into clinical rapid diagnosis, leading to a 30-fold lower limit of detection. Additionally, the captured viruses can be released under physiological conditions, delivering purified viruses with >50% recovery and without decreasing their native infectivity. Notably, this glycobead platform will facilitate the sensitive detection and continuous one-step purification of the target virus that contributes to future vaccine production.
- Published
- 2021
4. Donor <scp>Preactivation‐Based</scp> Glycosylation: An Efficient Strategy for Glycan Synthesis
- Author
-
Xianjin Qin and Xin-Shan Ye
- Subjects
Glycan ,chemistry.chemical_compound ,Glycosylation ,biology ,chemistry ,Stereochemistry ,biology.protein ,General Chemistry ,Chemoselectivity ,Solvent effects ,Oligosaccharide synthesis - Published
- 2021
5. Synthesis and immunological evaluation of N-acyl modified Globo H derivatives as anticancer vaccine candidates
- Author
-
Chengcheng Song, Xiu-Jing Zheng, Xin-Shan Ye, and Canjia Zhai
- Subjects
Synthetic vaccine ,Glycosylation ,Glycoconjugate ,medicine.medical_treatment ,Pharmaceutical Science ,H antigen ,010402 general chemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Immune system ,Drug Discovery ,medicine ,Pharmacology ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,Immunogenicity ,Organic Chemistry ,0104 chemical sciences ,chemistry ,Cancer research ,biology.protein ,Molecular Medicine ,Antibody ,Adjuvant - Abstract
Globo H is a tumor-associated carbohydrate antigen (TACA), which serves as a valuable target for antitumor vaccine or cancer immunotherapies. However, most TACAs are T-cell-independent, and they cannot induce powerful immune response due to their poor immunogenicity. To address this problem, herein, several Globo H analogues with modification on the N-acyl group were prepared through a preactivation-based glycosylation strategy from the non-reducing end to the reducing end. These modified Globo H derivatives were then conjugated with carrier protein CRM197 to form glycoconjugates as anticancer vaccine candidates, which were used in combination with adjuvant glycolipid C34 for immunological studies. The immunological effects of these synthetic vaccine candidates were evaluated on Balb/c mice. The results showed that the fluorine-modified N-acyl Globo H conjugates can induce higher titers of IgG antibodies that can recognize the naturally occurring Globo H antigen on the surface of cancer cells and can eliminate cancer cells in the presence of a complement, indicating the potential of these synthetic glycoconjugates as anticancer vaccine candidates.
- Published
- 2021
6. Visible-light-promoted 3,5-dimethoxyphenyl glycoside activation and glycosylation
- Author
-
Qin Li, De-Cai Xiong, Yafei Cao, Xin-Shan Ye, Runze Mao, Da-Ke Liu, Feng Xia, Jianhui Liu, Min-Min Zhou, and You Zou
- Subjects
chemistry.chemical_classification ,animal structures ,Glycosylation ,Stereochemistry ,Metals and Alloys ,Glycoside ,macromolecular substances ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nucleobase ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Visible spectrum - Abstract
A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers both O-glycosides and N-glycosides in moderate to excellent yields using a wide range of O-nucleophiles and nucleobases as the glycosyl acceptors.
- Published
- 2021
7. Recent advances in glycan synthesis
- Author
-
Xin-Shan Ye and Bo-Han Li
- Subjects
0301 basic medicine ,Glycan ,Glycosylation ,biology ,Chemistry ,Stereoisomerism ,Chemistry Techniques, Synthetic ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Chemical synthesis ,Enzymes ,0104 chemical sciences ,Analytical Chemistry ,carbohydrates (lipids) ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Polysaccharides ,biology.protein - Abstract
Carbohydrates play important roles in life science, but their synthesis is always hampered by their complicated chemical structures. Scientists have never stopped trying to solve the problem of glycan synthesis from various aspects. Here a brief overview of recent progress in glycan synthesis, including chemical approaches, chemoenzymatic approaches, and automated synthesis, will be discussed, focusing on the efficiency of new glycosylation methods, the stereoselectivity of coupled products, and their applications in the assembly of complex glycan chains.
- Published
- 2020
8. Design, Synthesis, and Structure–Activity Relationships of Indoline-Based Kelch-like ECH-Associated Protein 1-Nuclear Factor (Erythroid-Derived 2)-Like 2 (Keap1-Nrf2) Protein–Protein Interaction Inhibitors
- Author
-
Tian Liu, Jing Zhao, Han Zhang, Lv-Bin Hu, Qidong You, Xue Li, Wen-Xin Shan, Yan Wang, Zheng-Yu Jiang, and Hai-Shan Zhou
- Subjects
Cardiotonic Agents ,Indoles ,NF-E2-Related Factor 2 ,Oxidative phosphorylation ,Plasma protein binding ,01 natural sciences ,Protein–protein interaction ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Downregulation and upregulation ,Drug Discovery ,Humans ,Structure–activity relationship ,030304 developmental biology ,0303 health sciences ,Kelch-Like ECH-Associated Protein 1 ,KEAP1 ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Biochemistry ,chemistry ,Drug Design ,Indoline ,Thermodynamics ,Molecular Medicine ,Protein Binding - Abstract
The Keap1 (Kelch-like ECH-associated protein 1)-Nrf2 (nuclear factor erythroid 2-related factor 2)-ARE (antioxidant response element) pathway is the major defending mechanism against oxidative stresses, and directly disrupting the Keap1-Nrf2 protein-protein interaction (PPI) has been an attractive strategy to target oxidative stress-related diseases, including cardiovascular diseases. Here, we describe the design, synthesis, and structure-activity relationships (SARs) of indoline-based compounds as potent Keap1-Nrf2 PPI inhibitors. Comprehensive SAR analysis and thermodynamics-guided optimization identified 19a as the most potent inhibitor in this series, with an IC50 of 22 nM in a competitive fluorescence polarization assay. Further evaluation indicated the proper drug-like properties of 19a. Compound 19a dose-dependently upregulated genes and protein level of Nrf2 as well as its downstream markers and showed protective effects against lipopolysaccharide-induced injury in both H9c2 cardiac cells and mouse models. Collectively, we reported here a novel indoline-based Keap1-Nrf2 PPI inhibitor as a potential cardioprotective agent.
- Published
- 2020
9. Carbocyclic Ring Closure of Aryl C-Glycosides Promoted by Fluoroboric Acid
- Author
-
Shengbiao Tang, Xin-Shan Ye, De-Cai Xiong, Qin Li, and Qiannan Zheng
- Subjects
chemistry.chemical_classification ,C glycosides ,Solvent ,chemistry.chemical_compound ,Chemistry ,Fluoroboric acid ,Yield (chemistry) ,Aryl ,Organic Chemistry ,Glycoside ,Ring (chemistry) ,Medicinal chemistry - Abstract
A novel transformation from rhamnose-type C-glycosides to 2-cyclopentenones is described. With the promotion of fluoroboric acid, C-glycosides underwent ring opening and subsequent Nazarov cyclization to afford 2-cyclopentenones in good to excellent yields. The solvent and the concentration of acid are crucial to the yield of this transformation.
- Published
- 2020
10. Rapid and Prolonged Antidepressant-like Effect of Crocin Is Associated with GHSR-Mediated Hippocampal Plasticity-related Proteins in Mice Exposed to Prenatal Stress
- Author
-
Dong Xiao, Ruyan Wu, Weiwei Tao, Yu Dong, and Xin Shan
- Subjects
Physiology ,Offspring ,Cognitive Neuroscience ,Growth hormone secretagogue receptor ,Hippocampal formation ,Pharmacology ,Hippocampus ,Biochemistry ,Crocin ,Mice ,Phosphatidylinositol 3-Kinases ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Animals ,Medicine ,Receptors, Ghrelin ,Adverse effect ,PI3K/AKT/mTOR pathway ,030304 developmental biology ,Mice, Inbred BALB C ,0303 health sciences ,Neuronal Plasticity ,business.industry ,digestive, oral, and skin physiology ,Cell Biology ,General Medicine ,Carotenoids ,Antidepressive Agents ,chemistry ,Prenatal stress ,Antidepressant ,Female ,business ,Stress, Psychological ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Prenatal stress (PNS) has a prolonged and adverse effect on offspring, leading to a significantly increased vulnerability to developing depression in their later life. Traditional therapies have delayed onset and limited efficacy; thus, it remains an urgent need to find novel medications with fast-onset and high-efficacy potentials. Crocin, with its structure clearly examined, has shown antidepressant-like effects. However, few studies extensively investigated its effect especially in mice exposed to PNS. Using an established PNS model, we tested whether crocin could have a rapid and persistent antidepressant-like effect in PNS mice. Growth hormone secretagogue receptor (GHSR) and phosphoinositide 3-kinase (PI3K) inhibitors were used to test their effects in antidepressant-like effect of crocin. Hippocampal GHSR-PI3K signaling was examined both in PNS mice treated with a single dose of crocin and in combination of GHSR inhibitor. PNS mice showed depression-like behaviors at juvenile and adulthood, and crocin induced an instant and persistent antidepressant-like response in PNS mice in a dose-dependent manner. Moreover, crocin increased the expression of hippocampal synaptic plasticity-associated proteins through the restoration of GHSR-PI3K signaling. Inhibitions of both GHSR and PI3K abolished the effect of crocin in alleviating depressive-like behaviors. More importantly, GHSR inhibitor JMV2959 blocked the enhanced expression of hippocampal plasticity-related proteins induced by crocin. The present study demonstrated that crocin induced a fast-onset and prolonged antidepressant effect in PNS mice and suggested that GHSR-PI3K signaling may play a key role in crocin's effect at least partially by a restoration of hippocampal synaptic plasticity-associated proteins.
- Published
- 2020
11. Engineering a bacterial sialyltransferase for di-sialylation of a therapeutic antibody
- Author
-
Yue Wang, Xin-Shan Ye, Liangren Zhang, Mingqun Wang, Kaimeng Liu, Zhenming Liu, and Xiaodong Dou
- Subjects
chemistry.chemical_classification ,Glycosylation ,biology ,Photobacterium ,Sialyltransferase ,Organic Chemistry ,Mutant ,Mutagenesis (molecular biology technique) ,Protein Engineering ,Biochemistry ,Antibodies ,Sialyltransferases ,carbohydrates (lipids) ,chemistry.chemical_compound ,Enzyme ,chemistry ,Sialic Acids ,biology.protein ,Physical and Theoretical Chemistry ,Antibody ,Bioorthogonal chemistry ,Glycoprotein ,beta-D-Galactoside alpha 2-6-Sialyltransferase - Abstract
Terminal α-2,6-sialylation of N-glycans is a humanized glycosylation that affects the properties and efficacy of therapeutic glycoproteins. Fc di-sialylation (a biantennary N-glycan with two α-2,6-linked sialic acids) of IgG antibodies imparts them with enhanced anti-inflammatory activity and other roles. However, the microheterogeneity of N-glycoforms presents a challenge for therapeutic development. Therefore, controlled sialylation has drawn considerable attention, but direct access to well-defined di-sialylated antibodies remains limited. Herein, a one-pot three-enzyme protocol was developed by engineering a bacterial sialyltransferase to facilitate the modification of therapeutic antibodies with N-acetylneuraminic acid or its derivatives towards optimized glycosylation. To overcome the low proficiency of bacterial sialyltransferase in antibody remodeling, the Photobacterium sp. JT-ISH-224 α-2,6-sialyltransferase (Psp2,6ST) was genetically engineered by terminal truncation and site-directed mutagenesis based on its protein crystal structure. With the optimized reaction conditions and using activity-based screening of various Psp2,6ST variants, a truncated mutant Psp2,6ST (111-511)-His6 A235M/A366G was shown to effectively improve the catalytic efficiency of antibody di-sialylation. Herceptin and the donor substrate promiscuity allow the introduction of bioorthogonal modifications of N-acetylneuraminic acid into antibodies for site-specific conjugation. 2-AB hydrophilic interaction chromatography analysis of the released N-glycans and intact mass characterization confirmed the high di-sialylation of Herceptin via the optimized one-pot three-enzyme reaction. This study established a versatile enzymatic approach for producing highly di-sialylated IgG antibodies. It provides new insights into engineering bacterial sialyltransferase for adaptation to the enzymatic glycoengineering of therapeutic antibodies and the glycosite-specific conjugation of antibodies.
- Published
- 2020
12. C-Glycosylation enabled by N-(glycosyloxy)acetamides
- Author
-
Xia Wu, De-Cai Xiong, Bo-Han Li, Meng Liu, Miao Liu, Tian Li, and Xin-Shan Ye
- Subjects
Reaction conditions ,chemistry.chemical_classification ,Glycosylation ,Silylation ,Aryl ,Organic Chemistry ,Biochemistry ,Enol ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Organic chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Phenols ,Physical and Theoretical Chemistry ,Alkyl - Abstract
The C-glycosylation of C-nucleophiles including allyltrimethylsilane, silyl enol ethers and phenols with N-(glycosyloxy)acetamides as glycosyl donors has been realized. This protocol provides a convenient and practical route for the synthesis of alkyl C-glycosides and aryl 2-deoxy-β-C-glycosides under mild reaction conditions.
- Published
- 2020
13. Total synthesis of tumor-associated KH-1 antigen core nonasaccharideviaphoto-induced glycosylation
- Author
-
Congying Wu, Hong Yang, Bo-Han Li, Yuxin Yin, De-Cai Xiong, Wenlong Yao, and Xin-Shan Ye
- Subjects
carbohydrates (lipids) ,chemistry.chemical_classification ,chemistry.chemical_compound ,Glycosylation ,KH-1 antigen ,Antigen ,Chemistry ,Stereochemistry ,Organic Chemistry ,Core (graph theory) ,Total synthesis ,lipids (amino acids, peptides, and proteins) ,Glycosidic bond - Abstract
The synthesis of tumor-associated KH-1 antigen core nonasaccharide was achieved. All key glycosidic linkages were efficiently constructed by photo-induced glycosylation. The success of this total synthesis provides an example for the preparation of complex oligosaccharides using light-driven glycosylation reactions.
- Published
- 2020
14. The Smad3-miR-29b/miR-29c axis mediates the protective effect of macrophage migration inhibitory factor against cardiac fibrosis
- Author
-
Jie-Ning Zhu, Xian-Hong Fang, Hui Li, Rong Pan, Jian-Fang Luo, Jing Yang, Jin-Dong Xu, Zhen Xiao, Jingnan Liang, Xiao Zou, Ming Zhang, Sheng Wang, Shujing Yuan, Ni Zeng, Zhi-Xin Shan, and Yong-Heng Fu
- Subjects
Male ,0301 basic medicine ,Naringenin ,MMP2 ,Cardiac fibrosis ,Cardiomegaly ,030204 cardiovascular system & hematology ,Matrix (biology) ,Collagen Type I ,Mice ,Transforming Growth Factor beta2 ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,otorhinolaryngologic diseases ,medicine ,Animals ,Smad3 Protein ,RNA, Small Interfering ,3' Untranslated Regions ,Macrophage Migration-Inhibitory Factors ,Molecular Biology ,Mice, Knockout ,chemistry.chemical_classification ,Reactive oxygen species ,Myocardium ,Histocompatibility Antigens Class II ,Fibroblasts ,medicine.disease ,Fibrosis ,Up-Regulation ,Antigens, Differentiation, B-Lymphocyte ,Collagen Type I, alpha 1 Chain ,Mice, Inbred C57BL ,MicroRNAs ,030104 developmental biology ,chemistry ,Cancer research ,Matrix Metalloproteinase 2 ,Molecular Medicine ,RNA Interference ,Macrophage migration inhibitory factor ,Transforming growth factor - Abstract
Although macrophage migration inhibitory factor (MIF) is known to have antioxidant property, the role of MIF in cardiac fibrosis has not been well understood. We found that MIF was markedly increased in angiotension II (Ang-II)-infused mouse myocardium. Myocardial function was impaired and cardiac fibrosis was aggravated in Mif-knockout (Mif-KO) mice. Functionally, overexpression of MIF and MIF protein could inhibit the expression of fibrosis-associated collagen (Col) 1a1, COL3A1 and α-SMA, and Smad3 activation in mouse cardiac fibroblasts (CFs). Consistently, MIF deficiency could exacerbate the expression of COL1A1, COL3A1 and α-SMA, and Smad3 activation in Ang-II-treated CFs. Interestingly, microRNA-29b-3p (miR-29b-3p) and microRNA-29c-3p (miR-29c-3p) were down-regulated in the myocardium of Ang-II-infused Mif-KO mice but upregulated in CFs with MIF overexpression or by treatment with MIF protein. MiR-29b-3p and miR-29c-3p could suppress the expression of COL1A1, COL3A1 and α-SMA in CFs through targeting the pro-fibrosis genes of transforming growth factor beta-2 (Tgfb2) and matrix metallopeptidase 2 (Mmp2). We further demonstrated that Mif inhibited reactive oxygen species (ROS) generation and Smad3 activation, and rescued the decrease of miR-29b-3p and miR-29c-3p in Ang-II-treated CFs. Smad3 inhibitors, SIS3 and Naringenin, and Smad3 siRNA could reverse the decrease of miR-29b-3p and miR-29c-3p in Ang-II-treated CFs. Taken together, our data demonstrated that the Smad3-miR-29b/miR-29c axis mediates the inhibitory effect of macrophage migration inhibitory factor on cardiac fibrosis.
- Published
- 2019
15. Glycan Assembly Strategy: From Concept to Application
- Author
-
Xianjin Qin, Mingli Liu, and Xin-Shan Ye
- Subjects
Glycan ,Glycosylation ,biology ,Carbohydrate chemistry ,Chemistry ,General Chemical Engineering ,Carbohydrate synthesis ,General Chemistry ,Computational biology ,Biochemistry ,carbohydrates (lipids) ,chemistry.chemical_compound ,Hot topics ,Polysaccharides ,Materials Chemistry ,Natural source ,biology.protein - Abstract
Glycans have been hot topics in recent years due to their exhibition of numerous biological activities. However, the heterogeneity of their natural source and the complexity of their chemical synthesis impede the progress in their biological research. Thus, the development of glycan assembly strategies to acquire plenty of structurally well-defined glycans is an important issue in carbohydrate chemistry. In this review, the latest advances in glycan assembly strategies from concepts to their applications in carbohydrate synthesis, including chemical and enzymatic/chemo-enzymatic approaches, as well as solution-phase and solid-phase/tag-assisted synthesis, are summarized. Furthermore, the automated glycan assembly techniques are also outlined.
- Published
- 2021
16. Electrochemical Trifluoromethylation of Glycals
- Author
-
Zhao-Xiang Luo, De-Cai Xiong, Tian Li, Miao Liu, and Xin-Shan Ye
- Subjects
chemistry.chemical_compound ,Trifluoromethyl ,Trifluoromethylation ,Chemistry ,Organic Chemistry ,Regioselectivity ,Electrochemistry ,Redox mediator ,Combinatorial chemistry ,Oxidation-Reduction - Abstract
Carbohydrates play essential roles in various physiological and pathological processes. Trifluoromethylated compounds have wide applications in the field of medicinal chemistry. Herein, we report a practical and efficient trifluoromethylation of glycals by an electrochemical approach using CF3SO2Na as the trifluoromethyl source and MnBr2 as the redox mediator. A variety of trifluoromethylated glycals bearing different protective groups are obtained in 60-90% yields with high regioselectivity. The successful capture of a CF3 radical indicates that a radical mechanism is involved in this reaction.
- Published
- 2021
17. Synthesis and biological evaluation of bergenin derivatives as new immunosuppressants
- Author
-
Youhong Niu, Qin Li, Meng Wang, Xin-Shan Ye, Yan-Fen Wu, Chengcheng Song, and Lihua Deng
- Subjects
Pharmacology ,biology ,Organic Chemistry ,Pharmaceutical Science ,Bergenin ,Alkylation ,biology.organism_classification ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,Chemistry ,chemistry ,Drug Discovery ,Splenocyte ,Molecular Medicine ,Bergenia ,Inhibitory effect ,IC50 ,Biological evaluation - Abstract
Bergenin, which is isolated from Bergenia species, exhibits various pharmacological properties. In the search for new types of immunosuppressants, a series of bergenin derivatives were designed and synthesized, and their immunosuppressive effects were evaluated by the CCK-8 assay. The experimental data demonstrated that compounds 7 and 13 showed the strongest inhibition effects on mouse splenocyte proliferation (IC(50) = 3.52 and 5.39 μM, respectively). Further studies revealed that the inhibitory effect may come from the suppression of both IFN-γ and IL-4 cytokines. Alkylated derivatives of bergenin with n-hexyl and n-heptyl on the two phenolic hydroxyl groups showed better inhibitory activities. The hydrophobicity of bergenin derivatives, the configuration of the 4-OH in bergenin, and the ability to form hydrogen bonds of the substituents on the C-4 position are important to the immunosuppressive activity. This work proved that the modifications of bergenin may represent a new route to the discovery of a new class of immunosuppressive agents.
- Published
- 2021
18. Copper-Nitrene-Catalyzed Desymmetric Oxaziridination/1,2-Alkyl Rearrangement of 1,3-Diketones toward Bicyclic Lactams
- Author
-
Chang-Sheng Zhang, Fu-Min Zhang, Jin-Xin Zhu, Xiao-Ming Zhang, Yong-Qiang Tu, Ming Yang, Li-Xin Shan, Xue Han, Hong Wang, and Wen-Shuo Zhang
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,Bicyclic molecule ,Nitrene ,General Chemistry ,Combinatorial chemistry ,Catalysis ,chemistry.chemical_compound ,chemistry ,Lactam ,Schmidt reaction ,Rearrangement reaction ,Alkyl - Abstract
Although copper-nitrene has been extensively studied as a versatile active species in various transformations, asymmetric reactions involving copper-nitrene have been limited to the aziridination of olefins. Herein, we report the novel copper-nitrene-catalyzed desymmetric oxaziridination reaction of cyclic diketones with alkyl azides and the subsequent rearrangement of the resulting highly active intermediate, which produces a synthetically challenging chiral bicyclic lactam containing a quaternary carbon center. This procedure not only enriches the copper-nitrene-catalyzed asymmetric reactions, but also provides an alternative strategy to address the inherent challenges of catalytic asymmetric Schmidt reactions. This unique reaction could inspire the investigation of novel copper-nitrene-catalyzed asymmetric transformations and their reaction mechanisms.
- Published
- 2021
19. Copper-mediated O-arylation of lactols with aryl boronic acids
- Author
-
De-Cai Xiong, Jing-Jing Sui, and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Chemistry ,Aryl ,Copper mediated ,Glycoside ,Substrate (chemistry) ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Combinatorial chemistry ,Coupling reaction ,0104 chemical sciences ,chemistry.chemical_compound ,Pyridine ,0210 nano-technology - Abstract
An efficient and novel methodology to access phenolic glycosides has been established by using copper-mediated coupling reaction of aryl boronic acids with hemiacetals. The reaction takes place normally in the presence of Cu(OAc)2 (1.0 equiv.) and pyridine (2.0 equiv.) at 40 °C. This protocol distinguishes itself by wide substrate scope, operational simplicity and giving rise to a myriad of phenolic glycosides in good to excellent yields.
- Published
- 2019
20. High-performance FET arrays enabled by improved uniformity of wafer-scale MoS2 synthesized via thermal vapor sulfurization
- Author
-
Fang Wang, Feng Yulin, Kailiang Zhang, Yue Li, Xichao Di, Junqing Wei, Baojun Zhang, and Xin Shan
- Subjects
Electron mobility ,Materials science ,Fabrication ,Semiconductor device fabrication ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,law ,Wafer ,Molybdenum disulfide ,business.industry ,Transistor ,Surfaces and Interfaces ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry ,Molybdenum ,Optoelectronics ,0210 nano-technology ,business ,Layer (electronics) - Abstract
The fabrication of wafer-scale multilayers molybdenum disulfide (MoS2) induced by sulfurizing molybdenum (Mo) seed layer could compatible with traditional semiconductor process but the random growth orientations especially the vertical aligned structures lead to the unreliability for electronic devices thus hindered their wide application. Here, we utilize multi-step heating (MH) sulfurization method to regulate the sulfurization rate and diffusion rate of thermal sulfur vapor, thus realize the fabrication of MoS2 nanofilms with wafer-level uniformity and based on this, we integrate back-gate field-effect transistor (FET) arrays with an average hole mobility of 0.9cm2 V−1 s−1 and high device yield (~98%) which illustrate the reliable electrical-performance among the device arrays and the high quality of the as-fabricated MoS2 nanofilms. Therefore, we believe our efforts could pave the way for fabricating wafer-scale transition metal dichalcogenides (TMDCs) nanofilms with high uniformity and promoting their application for the integration of electronics/optoelectronics.
- Published
- 2019
21. Fabrication of Tubular g‐C 3 N 4 with N‐Defects and Extended π‐Conjugated System for Promoted Photocatalytic Hydrogen Production
- Author
-
Guifang Ge, Zhongkui Zhao, and Xin Shan
- Subjects
Fabrication ,Materials science ,Organic Chemistry ,Graphitic carbon nitride ,Conjugated system ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Photocatalysis ,Hydrogen evolution ,Physical and Theoretical Chemistry ,Hydrogen production - Published
- 2019
22. Rapid glycosylation of 2′-benzoylphenyl glycosides promoted by TfOH
- Author
-
Da-Ke Liu, Qin Li, De-Cai Xiong, Xia Wu, and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Glycoside ,Substrate (chemistry) ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl - Abstract
A new glycosylation protocol based on 2′-benzoylphenyl glycosides has been developed. These glycosyl donors could be rapidly activated by TfOH at room temperature. The donors are readily available. The reaction exhibited a broad substrate scope and coupled products were obtained in high yields.
- Published
- 2019
23. Total Synthesis of a Hyperbranched N ‐Linked Hexasaccharide Attached to ATCV‐1 Major Capsid Protein without Precedent
- Author
-
Yong Wu, Yong-Shi Wang, Xin-Shan Ye, and De-Cai Xiong
- Subjects
Glycosylation ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Total synthesis ,Regioselectivity ,General Chemistry ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Chemical synthesis ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,Capsid ,medicine ,Acanthocystis turfacea Chlorella virus 1 - Abstract
Summary of main observation and conclusion The N-glycans attached to some chloroviruses comprise a hyperbranched core structure without precedent. We are interested in the chemical synthesis of the hexasaccharide attached to ATCV-1 (Acanthocystis turfacea Chlorella virus 1) for its distinct structure. After exploring four routes, the target hexasaccharide 2 was successfully synthesized for the first time in overall 10% yield over 8 steps from thioglycoside building blocks. This synthetic protocol is characterized by the three-component one-pot glycosylation and the regioselective glycosylation reactions. The disclosed synthetic approach to this new type of N-glycans will facilitate the in-depth understanding of their biological functions.
- Published
- 2018
24. Counteranion‐ and Solvent‐Mediated Chirality Transfer in the Supramolecular Polymerization of Luminescent Platinum(II) Complexes
- Author
-
Chi-Ming Che, Kam-Hung Low, Wei Lu, Xin-Shan Xiao, Wai-Pong To, Qingyun Wan, and Yong Chen
- Subjects
Supramolecular chirality ,010405 organic chemistry ,Intermolecular force ,Supramolecular chemistry ,Cationic polymerization ,General Chemistry ,General Medicine ,Photochemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Chirality (chemistry) - Abstract
The chirality of supramolecular polymeric materials is subtly affected by a delicate balance among various non-covalent interactions, the details of which are inadequately understood. Now, a fine balance of intermolecular interactions, including closed-shell metal-metal, dispersive and electrostatic interactions, is used to direct the delicate orientation of monomeric building blocks, thereby achieving the successful preparation of different nanostructures with distinct supramolecular chirality. Moreover, kinetically trapped and thermodynamically stable aggregates were monitored over time in the supramolecular polymerization of cationic PtII complexes. The dynamic self-assembly process can be successfully controlled by modifying the counteranion and solvent composition. A chiral doping approach can also be used to induce the chirality of an achiral PtII complex at the supramolecular level.
- Published
- 2018
25. Chemical synthesis of glycans and applications in carbohydrate-based vaccines
- Author
-
Yongshi Wang and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycan ,Glycosylation ,Glycobiology ,Glycoconjugate ,General Chemical Engineering ,Immunogenicity ,General Chemistry ,Biology ,Carbohydrate ,Polysaccharide ,Biochemistry ,Chemical synthesis ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,biology.protein - Abstract
Carbohydrates play important roles in many biological processes. However, the lack of resources of structurally-defined carbohydrates and their weak immunogenicity have always restricted the development of chemical glycobiology especially carbohydrate-based vaccines. The progress in chemical synthesis of carbohydrates and glycoconjugates has greatly promoted the development of carbohydrate-based vaccines including antibacterial vaccines, anti-tumor vaccines and anti-HIV vaccines. The use of one-pot glycosylation strategy and solid-phase glycosylation strategy is able to synthesize oligosaccharides and even polysaccharides more effectively than before. Glycoconjugates produced by combining the carbohydrate antigens and proper protein carriers improve the immunogenicity of carbohydrates. This review covers the general methods and strategies of carbohydrate chemical synthesis, and the recent development of carbohydrate-based vaccines, and also summarizes related work of our group, hoping to offer readers better understanding of chemical glycobiology especially carbohydrate-based vaccines.
- Published
- 2018
26. Curcumin-Activated Mesenchymal Stem Cells Derived from Human Umbilical Cord and Their Effects on MPTP-Mouse Model of Parkinson’s Disease: A New Biological Therapy for Parkinson’s Disease
- Author
-
Jinfeng Li, Simiao Zhang, Shanshan Wang, Shang Guo, Hai-Tao Wang, Xin-Shan Liu, Xiaopeng Yang, Yunliang Wang, Wei Zheng, Peng Xue, Zhilei Zeng, and Linlin Hua
- Subjects
Parkinson's disease ,Tyrosine hydroxylase ,Article Subject ,Cell growth ,MPTP ,Dopaminergic ,Mesenchymal stem cell ,Caspase 3 ,Cell Biology ,medicine.disease ,RC31-1245 ,Transplantation ,chemistry.chemical_compound ,chemistry ,Cancer research ,medicine ,Molecular Biology ,Internal medicine ,Research Article - Abstract
Background. The aim of this study was to investigate the effects of human umbilical cord mesenchymal stem cell activated by curcumin (hUC-MSCs-CUR) on Parkinson’s disease (PD). hUC-MSCs can differentiate into many types of adult tissue cells including dopaminergic (DA) neurons. CUR could protect DA neurons from apoptosis induced by 6-hydroxydopamine (6-OHDA). Therefore, we used the hUC-MSCs activated by CUR for the treatment of PD in an animal model. Methods. The hUC-MSCs-CUR was transplanted into the MPTP-induced PD mouse models via the tail vein. We found that hUC-MSCs-CUR significantly improved the motor ability, increased the tyrosine hydroxylase (TH), dopamine (DA), and Bcl-2 levels, and reduced nitric oxide synthase, Bax, and cleaved caspase 3 expression in PD mice. The supernatant of hUC-MSCs-CUR (CM-CUR) was used to stimulate the SH-SY5Y cellular model of PD; cell proliferation, differentiation, TH, and neuronal-specific marker microtubular-associated protein 2 (MAP2) expressions were examined. Results. Our data showed that CM-CUR significantly promoted cell proliferation and gradually increased TH and MAP2 expression in SH-SY5Y PD cells. The beneficial effects could be associated with significant increase of rough endoplasmic reticulum in the hUC-MSCs-CUR, which secretes many cytokines and growth factors beneficial for PD treatment. Conclusions. Transplantation of hUC-MSCs-CUR could show promise for improving the motor recovery of PD.
- Published
- 2020
27. Synthesis of N-Substituted Iminosugar Derivatives and Evaluation of Their Immunosuppressive Activities
- Author
-
Xin-Shan Ye, Zhuo Lv, Youhong Niu, Qin Li, and Chengcheng Song
- Subjects
Male ,Iminosugar ,Pharmacology ,Alkylation ,010402 general chemistry ,Inhibitory postsynaptic potential ,01 natural sciences ,Biochemistry ,Interferon-gamma ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,Amide ,Drug Discovery ,Splenocyte ,Animals ,General Pharmacology, Toxicology and Pharmaceutics ,IC50 ,Cells, Cultured ,Cell Proliferation ,Mice, Inbred BALB C ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Imino Sugars ,0104 chemical sciences ,Molecular Medicine ,Interleukin-4 ,Immunosuppressive Agents ,Spleen - Abstract
It is important to find more effective and safer immunosuppressants, because clinically used immunosuppressive agents have significant side effects. A series of N-substituted iminosugar derivatives were designed and synthesized, and their immunosuppressive effects were evaluated by the CCK-8 assay. The results revealed that iminosugars 10 e and 10 i, that is, (3R,4S)-1-(4-heptyloxylphenylethyl)pyrrolidine-3,4-diol and (3R,4S)-1-[2-(2-chloro-4-(p-tolylthio)-phenyl-1-yl)ethyl]pyrrolidine-3,4-diol, respectively, exhibited the strongest inhibitory effects on mouse splenocyte proliferation (IC50 =2.16 and 2.48 μm, respectively), whereas the iminosugars containing an amide group near the hydrophilic head (compounds 10 j-n) exhibited no inhibitory effects. Further studies revealed that the inhibitory effects on splenocyte proliferation may have come from the suppression of both IFN-γ and IL-4 cytokines. Our results suggest that synthetic iminosugars, especially compounds 10 e and 10 i, hold potential as immunosuppressive agents.
- Published
- 2018
28. Involvement of Smad3 pathway in atrial fibrosis induced by elevated hydrostatic pressure
- Author
-
Jie-Ning Zhu, Fang Rao, Shulin Wu, Yong-Heng Fu, Zhao-Yu Wang, Chun-Yu Deng, Wei Wei, Zhi-Xin Shan, Xin Li, Meng-Zhen Zhang, Fangzhou Liu, Hui Yang, Wensi Zhu, and Yumei Xue
- Subjects
0301 basic medicine ,Naringenin ,medicine.medical_specialty ,Physiology ,Clinical Biochemistry ,Hydrostatic pressure ,Blood Pressure ,SMAD ,030204 cardiovascular system & hematology ,Collagen Type I ,Protein expression ,Transforming Growth Factor beta1 ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Left atrial ,Rats, Inbred SHR ,Internal medicine ,Atrial Fibrillation ,Hydrostatic Pressure ,medicine ,Animals ,Heart Atria ,Smad3 Protein ,Rats, Wistar ,Cells, Cultured ,Cell Proliferation ,business.industry ,Direct effects ,Atrial fibrillation ,Atrial Remodeling ,Cell Biology ,Fibroblasts ,medicine.disease ,Fibrosis ,Collagen Type I, alpha 1 Chain ,Disease Models, Animal ,Collagen Type III ,030104 developmental biology ,Endocrinology ,chemistry ,Hypertension ,Atrial fibrosis ,Matrix Metalloproteinase 2 ,business ,Signal Transduction - Abstract
Hypertension is a main risk factor for atrial fibrillation, but the direct effects of hydrostatic pressure on the atrial fibrosis are still unknown. The present study investigated whether hydrostatic pressure is responsible for atrial fibrosis, and addressed a potential role of the Smad pathway in this pathology. Biochemical assays were used to study regulation and expression of fibrotic factors in spontaneously hypertensive rats (SHRs) and Wistar rats, and in cardiac fibroblasts (CFs) cultured under standard (0 mmHg) and elevated (20, 40 mmHg) hydrostatic pressure. Levels of atrial fibrosis and protein expression of fibrotic factors Col-1A1/-3A1, TGF-β1, and MMP-2 in SHRs' left atrial tissues were higher than those in Wistar rats. Exposure to elevated pressure was associated with the proliferation of CFs. The protein expression of Col-1A1/-3A1, TGF-β1, and MMP-2 in CFs was also up-regulated in a pressure-dependent manner. The proliferation of CFs and increased expressions of fibrotic markers induced by elevated hydrostatic pressure could be reversed by the Smad3 inhibitor naringenin. The activation of Smad3 pathway was also stimulated by elevated hydrostatic pressure. These results demonstrate that CF secretory function and proliferation can be up-regulated by exposure to elevated pressure, and that Smad3 may modulate CF activation induced by high hydrostatic pressure.
- Published
- 2018
29. N -9 Alkylation of purines via light-promoted and metal-free radical relay
- Author
-
Yong-Shi Wang, Min-Min Zhou, Qin Li, Runze Mao, Xin-Shan Ye, Lifeng Sun, and De-Cai Xiong
- Subjects
Purine ,010405 organic chemistry ,General Chemistry ,Alkylation ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Metal free ,Purine metabolism ,Nucleoside ,Visible spectrum - Abstract
A metal-free and light-promoted approach to the synthesis of N -9 alkylated purine nucleoside derivatives, via a CF 3 radical triggered radical relay pathway, has been developed. Purine nucleoside derivatives were prepared regioselectively in good to high yields. Photosensitizers and metals are free in this transformation. Visible light or even sunlight can be used as the source of light for the reactions.
- Published
- 2018
30. 131I-Evans blue: evaluation of necrosis targeting property and preliminary assessment of the mechanism in animal models
- Author
-
Qiaomei Jin, Nan Yao, Zhiqi Yin, Dejian Huang, Dong Jian Zhang, Wei Liu, Fei Peng, Xin Shan, Jian Zhang, Qi Luo, and Yuan-Yu Zhao
- Subjects
0301 basic medicine ,Pathology ,Necrosis ,CT-DNA, calf-thymus DNA ,T2WI, T2-weighted imaging ,RPLI, reperfused liver infarction ,chemistry.chemical_compound ,0302 clinical medicine ,DWI, diffusion-weighted imaging ,T1WI, T1-weighted imaging ,General Pharmacology, Toxicology and Pharmaceutics ,Hyp, hypericin ,Evans Blue ,Neurodegeneration ,Necrosis imaging ,% ID/g, percentage of the injected dose per gram of tissue ,EB, evans blue ,Radioactivity ,030220 oncology & carcinogenesis ,Original Article ,H&E, haematoxylin-eosin ,medicine.symptom ,medicine.medical_specialty ,Programmed cell death ,Biodistribution ,DMSO, dimethylsulfoxide ,RCP, radiochemical purity ,CE-T1WI, contrast-enhanced T1WI ,Biology ,PI, propidium iodide ,Necrosis avidity ,03 medical and health sciences ,medicine ,Avidity ,DNA binding ,131I-Evans blue ,131I-EB, 131I-evans blue ,RFA, radiofrequency ablation ,MPS, mononuclear phagocyte system ,NAAs, necrosis-avid agents ,TLC, thin layer chromatography ,lcsh:RM1-950 ,medicine.disease ,In vitro ,lcsh:Therapeutics. Pharmacology ,030104 developmental biology ,chemistry ,MRI, magnetic resonance imaging ,DNA ,SD rats, Sprague–Dawley rats - Abstract
Necrosis is a form of cell death, which is related to various serious diseases such as cardiovascular disease, cancer, and neurodegeneration. Necrosis-avid agents (NAAs) selectively accumulated in the necrotic tissues can be used for imaging and/or therapy of related diseases. The aim of this study was to preliminarily investigate necrosis avidity of 131I-evans blue (131I-EB) and its mechanism. The biodistribution of 131I-EB at 24 h after intravenous administration showed that the radioactivity ratio of necrotic to viable tissue was 3.41 in the liver and 11.82 in the muscle as determined by γ counting in model rats. Autoradiography and histological staining displayed preferential uptake of 131I-EB in necrotic tissues. In vitro nuclear extracts from necrotic cells exhibited 82.3% of the uptake in nuclei at 15 min, as well as 79.2% of the uptake at 2 h after 131I-EB incubation. The DNA binding study demonstrated that evans blue (EB) has strong binding affinity with calf-thymus DNA (CT-DNA) (Ksv=5.08×105 L/(mol/L)). Furthermore, the accumulation of 131I-EB in necrotic muscle was efficiently blocked by an excess amount of unlabeled EB. In conclusion, 131I-EB can not only detect necrosis by binding the DNA released from necrotic cells, but also image necrotic tissues generated from the disease clinically., Graphical abstract In the present study, we demonstrated that 131I-evens blue (EB) could specifically bind to necrotic tissues image necrosis in living animals. Furthermore, the necrosis targeting mechanism of EB might be attributed to its binding to exposed DNA in necrotic areas.fx1
- Published
- 2017
31. A five-component one-pot synthesis of phosphatidylinositol pentamannoside (PIM5)
- Author
-
Xin-Shan Ye, De-Cai Xiong, and Dong Wang
- Subjects
chemistry.chemical_compound ,Glycosylation ,chemistry ,010405 organic chemistry ,Stereochemistry ,One-pot synthesis ,Regioselectivity ,Inositol ,General Chemistry ,Phosphatidylinositol ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Abstract
A practical and efficient synthesis of phosphatidylinositol pentamannoside (PIM5) was achieved based on a five-component one-pot sequential glycosylation protocol with exclusive regio- and stereo-selectivity. Two regioselective sequential glycosylations on inositol and p-tolyl thioglycosides as the sole type of building blocks made this protocol to avoid the tedious protective group manipulations. This synthetic strategy provides access to other important glycolipids with similar structures.
- Published
- 2018
32. The enhancement of TXA 2 receptors-mediated contractile response in intrarenal artery dysfunction in type 2 diabetic mice
- Author
-
Chun-Yu Deng, Fang Rao, Shulin Wu, Chun-Bo Chen, Qiu-Xiong Lin, Xiao-Yan Chen, Li Jiang, Su-Juan Kuang, Hui Yang, Jie-Sheng Qian, Meng-Zhen Zhang, Zhi-Xin Shan, and Yumei Xue
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Vascular smooth muscle ,medicine.drug_class ,030204 cardiovascular system & hematology ,Calcium in biology ,03 medical and health sciences ,Thromboxane A2 ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Receptor ,Pharmacology ,business.industry ,Receptor antagonist ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,chemistry ,lipids (amino acids, peptides, and proteins) ,medicine.symptom ,business ,Vasoconstriction ,circulatory and respiratory physiology ,Myograph ,Artery - Abstract
Thromboxane A2 (TXA2) has been implicated in the pathogenesis of diabetic vascular complications, although the underlying mechanism remains unclear. The present study investigated the alterations in TXA2 receptor signal transduction in type 2 diabetic renal arteries. The contraction of renal arterial rings in control (db/m+) mice and type 2 diabetic (db/db) mice was measured by a Multi Myograph System. Intracellular calcium concentration ([Ca2+]i) in vascular smooth muscle cells was measured by Fluo-4/AM dye and confocal laser scanning microscopy. Quantitative real-time PCR and Western blot analysis were used to determine gene and protein expression levels, respectively. A stable TXA2 mimic U46619 caused markedly stronger dose-dependent contractions in the renal arteries of db/db mice than in those of db/m+ mice. This response was completely blocked by a TXA2 receptor antagonist GR32191 and significantly inhibited by U73122. U46619-induced vasoconstriction was increased in the presence of nifedipine in db/db mice compared with that in db/m+ mice, whereas the response to U46619 did not differ between the two groups in the presence of SKF96365. Sarcoplasmic reticulum Ca2+ release-mediated and CaCl2-induced contractions did not differ between the two groups. In db/db mice, store-operated Ca2+(SOC) entry-mediated contraction in the renal arteries and SOC entry-mediated Ca2+ influx in smooth muscle cells were significantly increased. And the gene and protein expressions of TXA2 receptors, Orai1 and Stim1 were upregulated in the diabetic renal arteries. Therefore the enhancement of U46619-induced contraction was mediated by the upregulation of TXA2 receptors and downstream signaling in the diabetic renal arteries.
- Published
- 2017
33. Design, synthesis and cytotoxic evaluation of a novel series of benzo[d]thiazole-2-carboxamide derivatives as potential EGFR inhibitors
- Author
-
Chao Zhang, Xin-Shan Deng, Guang-Peng Meng, Wu Jiaofeng, Chun Hu, Qing-Chun Zhao, Lan Zhang, and Xue-Song Li
- Subjects
biology ,010405 organic chemistry ,medicine.drug_class ,Organic Chemistry ,Carboxamide ,Pharmacology ,biology.organism_classification ,01 natural sciences ,Molecular biology ,0104 chemical sciences ,HeLa ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Cell culture ,biology.protein ,medicine ,Cytotoxic T cell ,Epidermal growth factor receptor ,General Pharmacology, Toxicology and Pharmaceutics ,Thiazole ,Cytotoxicity ,EGFR inhibitors - Abstract
A novel series of benzo[d]thiazole-2-carboxamide derivatives have been de novo designed based on virtual screening methods. The target compounds were synthesized and evaluated for the cytotoxicity against epidermal growth factor receptor high-expressed cancer cell lines (A549, HeLa, and SW480), epidermal growth factor receptor low-expressed cell line (HepG2) and human liver normal cell line (HL7702). Several target compounds have showed moderate to excellent potency against A549, HeLa, and SW480 and weak cytotoxic effects against HepG2, which implies they are probably epidermal growth factor receptor inhibitors. And scarcely did they exhibit any activities against HL7702, which signifies they are likely to overcome the nonspecific toxicity against normal cells. Especially, the compound 6-[2-(diethylamino)-2-oxoethoxy]-N-(furan-2-ylmethyl)benzo[d]thiazole-2-carboxamide (6i) was identified as a promising agent, exhibiting the most potent cytotoxic activities with IC50 values of 4.05, 12.17, 6.76 μM against the A549, HeLa, and SW480 cell lines, respectively.
- Published
- 2017
34. Synthesis of Iminosugar-Containing KRN7000 Analogues
- Author
-
Lei Zhang and Xin-Shan Ye
- Subjects
0301 basic medicine ,Ceramide ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Alpha-GalCer ,Iminosugar ,General Chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Glycolipid ,Galactose ,Moiety - Abstract
Three new iminosugar-containing KRN7000 (also referred to as α-GalCer) analogues were designed and synthesized. In the design, the galactose moiety of KRN7000 was replaced by iminosugars and the iminosugar structures were connected with ceramide in different manners with a C-glycosidic bond instead of the O-glycosidic bond. To our knowledge, this is the first report in which iminosugars are incorporated in KRN7000 structure modifications. The synthetic compounds were evaluated for their ability to stimulate cytokine release. The results may benefit better understanding of structure-activity relationships and facilitate future design of more KRN7000 derivatives.
- Published
- 2017
35. Transition State-Based Sialyltransferase Inhibitors: Mimicking Oxocarbenium Ion by Simple Amide
- Author
-
Jian Guo, Wenming Li, Weiwei Xue, and Xin-Shan Ye
- Subjects
0301 basic medicine ,Magnetic Resonance Spectroscopy ,Glycosylation ,Sialyltransferase ,Stereochemistry ,Oxocarbenium ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Amide ,Drug Discovery ,Humans ,Moiety ,Enzyme Inhibitors ,Chromatography, High Pressure Liquid ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,Nuclear magnetic resonance spectroscopy ,Amides ,Sialyltransferases ,0104 chemical sciences ,Sialic acid ,carbohydrates (lipids) ,030104 developmental biology ,Enzyme ,chemistry ,biology.protein ,Molecular Medicine ,Spectrophotometry, Ultraviolet - Abstract
In the new transition-state based sialyltransferase inhibitors, an amide group was placed at the corresponding C-2 position of CMP-sialic acid to mimic the geometry and charge distribution in the transition state, and simple aromatic or aliphatic rings were used instead of the sialic acid moiety. All synthetic compounds exhibited excellent α(2-6)-sialyltransferase inhibition, resulting in up to a 2600-fold higher affinity for the enzyme than CMP-Neu5Ac, suggesting that amide is a key element for simulating transition-state features.
- Published
- 2017
36. Synthesis and biological evaluation of N-arylated-lactam-type iminosugars as potential immunosuppressive agents
- Author
-
Youhong Niu, Qin Li, Chengcheng Song, Xin-Shan Ye, Hai-Qian Liu, and Tao Li
- Subjects
Drug ,Lactams ,media_common.quotation_subject ,Molecular Conformation ,Iminosugar ,Pharmacology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Jurkat Cells ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,Splenocyte ,Animals ,Humans ,Structure–activity relationship ,MTT assay ,Physical and Theoretical Chemistry ,IC50 ,Cell Proliferation ,media_common ,Dose-Response Relationship, Drug ,010405 organic chemistry ,Chemistry ,Cell growth ,Organic Chemistry ,Combinatorial chemistry ,Imino Sugars ,0104 chemical sciences ,Lactam ,Immunosuppressive Agents ,Spleen - Abstract
Since the immunosuppressive agents currently used in clinics have significant side effects, it is very important to search for new effective and safe immunosuppressants. Iminosugars as a new class of immunosuppressants are less explored. In this report, 24 new N-arylated iminosugar derivatives, including d-talo and d-galacto epimers, were designed and synthesized, and their immunosuppressive effects were evaluated by MTT assay. The experimental data demonstrated that compound 20 showed the strongest inhibition effect (IC50 = 6.94 μM). Further studies revealed that the inhibitory effects on splenocyte proliferation may come from the suppression of both IFN-γ and IL-4 cytokines. The preliminary structure-activity relationship (SAR) analysis suggested that N-arylated d-galacto-type iminosugars showed better inhibitory activities than d-talo-type analogues. The SAR analysis also showed that the inhibition effect of iminosugars can be improved by decreasing the polarity or increasing the hydrophobicity. These results may be beneficial to the discovery of new iminosugar derivatives as immunosuppressive agents.
- Published
- 2017
37. Crocin induces anti-ischemia in middle cerebral artery occlusion rats and inhibits autophagy by regulating the mammalian target of rapamycin
- Author
-
Haoxin Wu, Haoran Wu, Ruizhi Jiang, Qinan Wu, Ke Bao, Xin Shan, Guangda Sun, Jie Xu, Zhiheng Huang, Xiaoyan Huang, and Weiwei Tao
- Subjects
0301 basic medicine ,Male ,Cell Survival ,Ischemia ,Down-Regulation ,Pharmacology ,Crocin ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Western blot ,In vivo ,medicine ,Autophagy ,Animals ,Protein kinase A ,PI3K/AKT/mTOR pathway ,medicine.diagnostic_test ,business.industry ,TOR Serine-Threonine Kinases ,Infarction, Middle Cerebral Artery ,medicine.disease ,Carotenoids ,Rats ,030104 developmental biology ,Mechanism of action ,chemistry ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Crocin, an active compound found in Gardenia jasminoides Ellis, has been shown to possess neuron-protective properties, but its potential mechanisms of action still remain poorly understood. In this study, the anti-ischemic effect and underlying mechanism of action of crocin were investigated in male rats with right middle cerebral artery occlusion/reperfusion. Computed tomography and magnetic resonance imaging were used to evaluate the area of infarction 24 h after reperfusion. Neurological scores were employed to evaluate nerve injury. Direct 2,3,5-triphenyltetrazolium chloride staining was used to calculate the infarct ratio 120 h after reperfusion. Finally, HT22 cells and Western blot were used to study the underlying mechanisms. Crocin showed a decreased infarct volume and neurological score in vivo, while the expression of LC3-II/I and AMP-activated protein kinase was remarkably down-regulated with increased levels of p62 and mammalian target of rapamycin (mTOR) expression. However, rapamycin significantly inhibited mTOR, which can impact the anti-ischemic effect of crocin in vitro. These results suggest that crocin may elicit an anti-ischemic effect probably through the mTOR pathway.
- Published
- 2019
38. Curcumin-Activated Mesenchymal Stem Cells Derived from Human Umbilical Cord and Their Effects on MPTP-Mice Model of Parkinson's Disease: A New Biological Therapy for Parkinson's Disease
- Author
-
Linlin Hua, Xiao Peng Yang, Xin-Shan Liu, Peng Xue, Si-Miao Zhang, Hai-Tao Wang, Jin-Feng Li, Shanshan Wang, Zhilei Zeng, Yunliang Wang, Hong-Wei Wang, and Wei Zheng
- Subjects
Parkinson's disease ,Tyrosine hydroxylase ,business.industry ,Cell growth ,MPTP ,Mesenchymal stem cell ,Pharmacology ,medicine.disease ,Umbilical cord ,Transplantation ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Dopamine ,medicine ,business ,medicine.drug - Abstract
The aim of this study was to investigate the effects of human umbilical cord mesenchymal stem cell activated by curcumin (hUC-MSCs-CUR) on Parkinson's disease (PD). The hUC-MSCs-CUR was transplanted into the MPTP-induced PD mouse models via the tail vein. We found that hUC-MSCs-CUR significantly improved the motor ability, increased the tyrosine hydroxylase (TH), dopamine (DA), and Bcl-2 levels, and reduced nitric oxide synthase, Bax, and cleaved-caspase 3 expression in PD mice. The supernatant of hUC-MSCs-CUR (CM-CUR) was used to stimulate the SH-SY5Y cellular model of PD; cell proliferation, differentiation, TH, and neuronal-specific marker microtubular associated protein 2 (MAP2) expressions were examined. Results showed that CM-CUR significantly promoted cell proliferation and gradually increased TH and MAP2 expression in SH-SY5Y PD cells. The beneficial effects could be associated with significant increase of rough endoplasmic reticulum in the hUC-MSCs-CUR, which secrete many cytokines and growth factors beneficial for PD treatment. Therefore, transplantation of hUC-MSCs-CUR could show promise for improving the motor recovery of PD. Funding Statement: This study was supported by Shangdong province nature and science funding, ZR2019MH065. Declaration of Interests: The authors declare no competing financial interests. Ethics Approval Statement: All the animal experiments described in this study and umbilical cord tissue collection were approved by the Ethics Committee of the 148th Hospital and the second affiliated hospital of Zhengzhou University.
- Published
- 2019
39. Chelerythrine Attenuates the Inflammation of Lipopolysaccharide-Induced Acute Lung Inflammation Through NF-κB Signaling Pathway Mediated by Nrf2
- Author
-
Lu Fan, Ye Fan, Li Liu, Weiwei Tao, Xin Shan, Yu Dong, Lin Li, Sen Zhang, and Hanqing Wang
- Subjects
0301 basic medicine ,LPS ,Lipopolysaccharide ,Inflammation ,Lung injury ,Pharmacology ,medicine.disease_cause ,NF-κB ,Nrf2 ,03 medical and health sciences ,chemistry.chemical_compound ,medicine ,Pharmacology (medical) ,Interleukin 6 ,chelerythrine ,Original Research ,biology ,lcsh:RM1-950 ,ALI ,lcsh:Therapeutics. Pharmacology ,030104 developmental biology ,Chelerythrine ,chemistry ,inflammation ,biology.protein ,Tumor necrosis factor alpha ,medicine.symptom ,Oxidative stress - Abstract
Chelerythrine (CH), is a kind of benzo[c] phenanthridine alkaloid isolated from plants such as Chelidonium, with pharmacological activities as antitumor, antibiosis and anti-inflammation. However, few studies have demonstrated whether CH could protect against lipopolysaccharide (LPS)-induced acute lung injury (ALI), and the underlying mechanism is also uncertain. The purpose of the present study was to investigate the anti-inflammatory effects of CH on LPS-induced ALI in mice and in RAW264.7 cells. In this study, we demonstrated that treatment with CH significantly ameliorated LPS-induced pathological changes in the lung. CH also attenuated LPS-induced W/D ratio, inflammatory cell infiltration. Meanwhile, LPS-induced Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) production and oxidative stress were markedly suppressed by CH. Furthermore, western blot showed that CH suppressed LPS-stimulated inflammation of RAW264.7 cells through activation of nuclear factor kappa-B (NF-κB) pathway. Knocking down of nuclear factor erythroid 2-related factor 2 (Nrf2) led to the reduction of nuclear translocation of the NF-κB p65, which triggered inflammation. These experimental results provided evidence that CH could be a potential therapeutic candidate for the intervention of ALI caused by LPS.
- Published
- 2018
- Full Text
- View/download PDF
40. A general approach to C-Acyl glycosides via palladium/copper Co-catalyzed coupling reaction of glycosyl carbothioates and arylboronic acids
- Author
-
Li-Na Wang, Qing-Hui Cai, Youhong Niu, Xin-Shan Ye, and Qin Li
- Subjects
chemistry.chemical_classification ,010405 organic chemistry ,Organic Chemistry ,Substrate (chemistry) ,chemistry.chemical_element ,Glycoside ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Copper ,Combinatorial chemistry ,Coupling reaction ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Glycosyl ,Palladium - Abstract
A general and efficient approach to the synthesis of various C-acyl glycosides has been developed via Pd2(dba)3/CuTC co-catalyzed cross-coupling reaction of glycosyl carbothioates with arylboronic acids. The reaction showed a broad substrate scope and 25 examples were exhibited in 61%–97% isolated yields. Furthermore, this reaction was applied to the gram-scale preparation of C-acyl glycosides. The coupled products can be further transformed into diverse biologically useful compounds, as exemplified by the synthesis of protected sergliflozin-A mimics.
- Published
- 2021
41. Study on the attenuated effect of Ginkgolide B on ferroptosis in high fat diet induced nonalcoholic fatty liver disease
- Author
-
Xin Shan, Yuwei Yang, Jie Wang, Qin Gao, Zhiyang Lv, and Jing Chen
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,NF-E2-Related Factor 2 ,Diet, High-Fat ,Toxicology ,GPX4 ,medicine.disease_cause ,Lipid peroxidation ,Palmitic acid ,Lactones ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Fibrinolytic Agents ,Non-alcoholic Fatty Liver Disease ,Internal medicine ,Nonalcoholic fatty liver disease ,medicine ,Animals ,Ferroptosis ,Humans ,Mice, Knockout ,chemistry.chemical_classification ,biology ,Chemistry ,Lipid metabolism ,Hep G2 Cells ,medicine.disease ,Mice, Inbred C57BL ,Ferritin ,Oxidative Stress ,Ginkgolides ,030104 developmental biology ,Endocrinology ,Transferrin ,biology.protein ,Lipid Peroxidation ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
Ginkgolide B (GB), a main constituent of Ginkgo biloba extracts, reduces hepatic lipid accumulation and ameliorates nonalcoholic fatty liver disease (NAFLD) in obese mice, but the potential mechanism is unclear. Here we investigated the attenuated effects of GB on the disorder of lipid metabolism, oxidative stress and iron deposition in NAFLD and its potential mechanism associated with ferroptosis. Our preliminary research focused on high fat diet (HFD)-induced ApoE-/-mice gavaged with GB (20 and 30 mg kg-1•d-1, approximately equal to the human dose of 2 and 3 mg kg-1•d-1, respectively) and palmitic acid and oleic acid (PA/OA)-induced HepG2 cells treated with GB (4, 8, 16 μg/mL), respectively. Hepatic injury was assessed via biochemical, histopathological and immunohistochemical evaluations. In order to examine the mechanism of GB on ferroptosis-regulated pathway, we analyzed the expression levels of ferroptosis-related proteins, including nuclear factor erythroid 2 (Nrf2), glutathione peroxidase 4 (GPX4), heme oxygenase-1 (HO-1), transferrin receptor-1 (TFR1) and ferritin heavy chain-1 (FTH1) in vivo and vitro experiments by Western blotting. In order to further verify the correlation pathway of ferroptosis, after Nrf2 short hairpin RNA interference, we analyzed the effects of GB on Nrf2 pathway. Both HFD-fed mice and PA/OA-induced HepG2 cells displayed ferroptosis-based panel of biomarkers such as iron overload with the up-regulation of TFR1 and the down-regulation of FTH1, lipid peroxidation and inhibition of Nrf2 activity, which further induced GPX4 and HO-1 levels. Remarkably, after Nrf2 interference, GB treatment significantly increased Nrf2 expression, indicating that GB exerted anti-ferroptosis effects by activation of Nrf2 pathway. Our results are preliminarily illustrated that GB treatment has a specific effect on lipid accumulation and oxidative stress caused ferroptosis in NAFLD, possibly through Nrf2 signaling pathway.
- Published
- 2020
42. Controlled synthesis of WS2 with different layers by tuning flow rates
- Author
-
Baojun Zhang, Jiaqiang Shen, Junqing Wei, Xin Lin, Xin Shan, Xichao Di, Kailiang Zhang, Yaowu Hao, and Fang Wang
- Subjects
Electron mobility ,Materials science ,business.industry ,Mechanical Engineering ,Bilayer ,Tungsten disulfide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Ion ,Volumetric flow rate ,Reaction rate ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Monolayer ,Optoelectronics ,General Materials Science ,Thin film ,0210 nano-technology ,business - Abstract
Two-dimensional tungsten disulfide (WS2) has been widely studied owing to its superior optical and electrical properties. Since the growth mechanism is unclear, controllable synthesis of 2D WS2 is still a challenge. Based on the analysis of the relationship between the mass transfer rate and the chemical reaction rate of the reactants, we control the lateral and longitudinal growth of the films by regulating the Ar flow rate in the growth stage, and then realize the controllable synthesis of WS2 films with monolayer, bilayer and tri-layer. In addition, back-gated FETs were fabricated based on WS2 thin films with different layers. Monolayer WS2 showed n-type characteristics with a carrier mobility of ~1.5 cm2 V−1 s−1, whereas bilayer WS2 showed a higher mobility of ~13 cm2 V−1 s−1 with the Ion/Ioff ratio of ~106. Our work paves the way for the development of next generation photoelectronic devices based on 2D materials.
- Published
- 2020
43. Adsorption performance and mechanism of As(V) uptake over mesoporous Y–Al binary oxide
- Author
-
Huirong Chen, Hang Liu, Xin Shan, Liming Zhang, Yongming Luo, Caiyun Han, Gengping Wan, and Jiushuai Deng
- Subjects
Aqueous solution ,General Chemical Engineering ,Inorganic chemistry ,Oxide ,Arsenate ,Langmuir adsorption model ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Rate-determining step ,01 natural sciences ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,chemistry ,symbols ,0210 nano-technology ,Mesoporous material ,Fluoride ,0105 earth and related environmental sciences - Abstract
Mesoporous Y–Al binary oxide was synthesized and employed as adsorbent to remove As(V) from aqueous solution in this study. The adsorbent was synthesized via incipient-wetness impregnation method, and then characterized by N 2 adsorption–desorption, XRD, TEM, EDS and FT-IR. The adsorption performance was tested by batch and column experiments. From the results of batch experiments, it was found that the adsorption processes were abided by pseudo-second-order, which illustrated that the rate limiting step was the “surface reaction”. And Langmuir isotherm model was fitted well to the equilibrium experiment data at near neutral, and the maximum adsorption capacity was 62.23 mg/g. Additionally, the coexisting anions of nitrate, silicate and sulphate have no significant interfering effect on As(V) uptake, while the presence of fluoride and phosphate caused the markedly reduction. According to the results of FT-IR spectrum and the pH change in the adsorption process, it could be concluded that the interaction between arsenate and hydroxyl group was involved in the adsorption process. From the results of column experiments, it can be observed that the breakthrough time was increased from 83 min to 125 min due to the incorporation of Y(III) oxide.
- Published
- 2016
44. 3-Butenyloxycarbonyl as a new hydroxyl protecting group in carbohydrate synthesis
- Author
-
Xin-Shan Ye, Youhong Niu, and Nana Zeng
- Subjects
Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Carbohydrate synthesis ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Organic chemistry ,Oxidative cleavage ,Protecting group - Abstract
3-Butenyloxycarbonyl (Bloc) has been identified as a new hydroxyl protecting group, which can be introduced under mild conditions in high yields and selectively removed by OsO4/NaIO4/2,6-lutidine in CH3CN–H2O without affecting most commonly-used protecting groups. Moreover, this new protecting group is inert under glycosylation conditions.
- Published
- 2016
45. Stereoselective Koenigs-Knorr Glycosylation Catalyzed by Urea
- Author
-
Xiaowei Wu, Xin-Shan Ye, De-Cai Xiong, and Lifeng Sun
- Subjects
animal structures ,Anomer ,Glycosylation ,Stereochemistry ,010405 organic chemistry ,fungi ,macromolecular substances ,General Chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Organocatalysis ,Urea ,Organic chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Stereoselectivity ,Selectivity ,Phosphine - Abstract
A stereoselective Koenigs-Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
- Published
- 2016
46. Removal As(V) by sulfated mesoporous Fe–Al bimetallic adsorbent: Adsorption performance and uptake mechanism
- Author
-
Liming Zhang, Caiyun Han, Xitong Li, Yongming Luo, Huirong Chen, Xin Shan, and Wenjie Zhu
- Subjects
021110 strategic, defence & security studies ,Hydrogen bond ,Process Chemistry and Technology ,Inorganic chemistry ,0211 other engineering and technologies ,Langmuir adsorption model ,02 engineering and technology ,Aluminium sulfate ,021001 nanoscience & nanotechnology ,Pollution ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,chemistry ,Monolayer ,medicine ,symbols ,Chemical Engineering (miscellaneous) ,Ferric ,0210 nano-technology ,Mesoporous material ,Waste Management and Disposal ,Bimetallic strip ,medicine.drug - Abstract
Sulfated mesoporous Fe–Al bimetallic adsorbent, prepared by a simple method of incipient-wetness impregnation, was employed as an efficient adsorbent to remove As(V) from solution. Removal performance was investigated by batch experiments with various factors, including ferric content, inorganic ferric additive, contact time, initial pH and adsorbent dosage. An interesting result was obtained that demonstrated that anions of inorganic ferric additive have a significant influence on As(V) removal, and the sample obtained from additive 10 wt% Fe2(SO4)3 was found to be a highly effective As(V) adsorbent. The experiment data were excellent fitted to Langmuir isotherm and the maximum monolayer uptake was about 98.13 mg/g at near neutral. And solution pH have a negligible influence on As(V) removal in the investigated pH region of 2.5–11.0. More importantly, adsorption equilibrium can be attained within 3 h, which is significantly shorter than that of MA (more than 12 h). Based on the results of batch experiments, pH changes, adsorption energy, XPS analyses and the chemical forms of As(V), the possible uptake mechanisms under the investigated conditions were proposed as follows: (1) during initial pH below 4, H2AsO4− and H3AsO4 were adsorbed by electrostatic interaction and hydrogen bond, respectively; (2) during initial pH higher than 4, the exchange between sulfate group and H2AsO4− was the dominantly interaction.
- Published
- 2016
47. A new GLP-1 analogue with prolonged glucose-lowering activity in vivo via backbone-based modification at the N-terminus
- Author
-
Xin-Shan Ye, Youhong Niu, Yan-Fen Wu, Jingjing Zhu, An-Qi Yang, and Xiaohui Bai
- Subjects
Blood Glucose ,0301 basic medicine ,Stereochemistry ,Clinical Biochemistry ,Pharmaceutical Science ,Endogeny ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Dipeptidyl peptidase ,03 medical and health sciences ,chemistry.chemical_compound ,Glucagon-Like Peptide 1 ,In vivo ,Amide ,Drug Discovery ,Humans ,Hypoglycemic Agents ,GLP-1 Analogue ,Receptor ,Molecular Biology ,Molecular Structure ,Chemistry ,Organic Chemistry ,In vitro ,0104 chemical sciences ,N-terminus ,030104 developmental biology ,Diabetes Mellitus, Type 2 ,Molecular Medicine - Abstract
Glucagon-like peptide-1 (GLP-1) is an endogenous insulinotropic hormone with wonderful glucose-lowering activity. However, its clinical use in type II diabetes is limited due to its rapid degradation at the N-terminus by dipeptidyl peptidase IV (DPP-IV). Among the N-terminal modifications of GLP-1, backbone-based modification was rarely reported. Herein, we employed two backbone-based strategies to modify the N-terminus of tGLP-1. Firstly, the amide N-methylated analogues 2–6 were designed and synthesized to make a full screening of the N-terminal amide bonds, and the loss of GLP-1 receptor (GLP-1R) activation indicated the importance of amide H-bonds. Secondly, with retaining the N-terminal amide H-bonds, the β-peptide replacement strategy was used and analogues 7–13 were synthesized. By two rounds of screening, analogue 10 was identified. Analogue 10 greatly improved the DPP-IV resistance with maintaining good GLP-1R activation in vitro, and showed approximately a 4-fold prolonged blood glucose-lowering activity in vivo in comparison with tGLP-1. This modification strategy will benefit the development of GLP-1-based anti-diabetic drugs.
- Published
- 2016
48. Thermal Decomposition Kinetics of Hexanitrohexaazaisowurtzitane/Ammonium Perchlorate
- Author
-
Qingjie Jiao, Ming-Xin Shan, Kang-Kang Wang, Yan-Li Zhu, Jing-Si Wang, and Zheng Xiaodi
- Subjects
Organic Chemistry ,Inorganic chemistry ,Chemical process of decomposition ,Kinetics ,Thermal decomposition ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ammonium perchlorate ,01 natural sciences ,Decomposition ,0104 chemical sciences ,Thermogravimetry ,Hexanitrohexaazaisowurtzitane ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,0210 nano-technology ,Thermal analysis - Abstract
The thermal decomposition kinetics of hexanitrohexaazaisowurtzitane/ ammonium perchlorate (HNIW/AP) have been investigated by thermogravimetry- differential scanning calorimetry-mass spectrometry (TG-DSC-MS) simultaneous analysis. TG showed that there were three weight loss processes for the thermal decomposition of the HNIW/AP mixture. The first was ascribed mainly to the thermal decomposition of HNIW, while the second and third were assigned to that of AP. The presence of AP has little effect on the thermal decomposition process of the HNIW component. The apparent activation energy of the thermal decomposition of the HNIW component, calculated by the Kissinger method, was little changed compared to that of neat HNIW. The addition of HNIW to AP caused the onset and end temperatures of the thermal decomposition to be decreased and the decomposition process to be shortened. The high-temperature and low- temperature decomposition processes of AP became blurred in the presence of HNIW, and this was supported by the MS results.
- Published
- 2016
49. Light-driven highly efficient glycosylation reactions
- Author
-
Runze Mao, Xin-Shan Ye, De-Cai Xiong, Qin Li, Jinyou Duan, and Fan Guo
- Subjects
Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Substrate (chemistry) ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Light driven ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Organic synthesis - Abstract
Glycosylation is unarguably the most important reaction in the field of glycochemistry. Photo-initiated reactions hold extraordinary potential in organic synthesis. Herein we report a novel light-driven strategy for the activation of thioglycosides via the merger of a CF3 radical pathway followed by the subsequent glycosylation with glycosyl acceptors. This protocol could efficiently activate thioglycosides, thereby greatly enhancing the substrate scope of reactions. In particular, the glycosylation reactions, which are completely inert under the existing photo-induced glycosylation conditions, proceeded smoothly in high yields. Many common protective groups were well tolerated under the coupling conditions. Both UV and visible light or even sunlight were used as the source of light for the reactions. The high efficiency of this light-driven glycosylation protocol was further highlighted by the rapid one-pot sequential assembly of oligosaccharides.
- Published
- 2016
50. Indolo-quinoline boron difluoride dyes: synthesis and spectroscopic properties
- Author
-
Xiao-Ping Cao, Xin-Shan Ye, Xiaojun Yao, Hui-Xin Luo, Youhong Niu, and Xiaojie Jin
- Subjects
010405 organic chemistry ,Organic Chemistry ,Quinoline ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,Fluorescence ,0104 chemical sciences ,chemistry.chemical_compound ,Suzuki reaction ,chemistry ,Boron difluoride ,Physical and Theoretical Chemistry - Abstract
Novel indolo-quinoline compounds were efficiently prepared via a Povarov-type reaction, and the structures were further modified by a Suzuki coupling reaction. The corresponding BF2-rigidified complexes were prepared and their spectroscopic properties were characterized with large Stokes shifts (up to 211 nm) and up to near-infrared (NIR) wavelength (667 nm). The synthetic complexes could be used as new fluorescent dyes.
- Published
- 2016
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.