查找使用阿拉丁产品的科研文献

Rational design of 2-benzylsulfinyl-benzoxazoles as potent and selective indoleamine 2, 3-dioxygenase 1 inhibitors to combat inflammation

Ting Wang,Xiufeng Liao,Xiaodi Zhao,Kai Chen,Yangzhonghui Chen,Hui Wen,Dali Yin,Yuchen Wang,Bin Lin,Sen Zhang,Huaqing Cui

Mimicking the transition state of tryptophan (Trp) and O 2 in the enzymatic reaction is an effective approach to design indoleamine 2, 3-dioxygenase 1 (IDO1) inhibitors. In this study, we firstly assembled a small library of 2-substituted benzo-fused five membered heterocycles and found 2-sulfinyl-benzoxazoles with interesting IDO1 inhibitory activities. Next the inhibitory activity toward IDO1 was gradually improved. Several benzoxazoles showed potent IDO1 inhibitory activity with IC 50 of 82–91 nM, and exhibited selectivity between IDO1 and tryptophan 2, 3-dioxygenase (TDO2). Enzyme binding studies showed that benzoxazoles are reversible type II IDO1 inhibitors, and modeling studies suggested that the oxygen atom of the sulfoxide in benzoxazoles interacts with the iron atom of the heme group, which mimics the transition state of Fe-O-O-Trp complex. Especially, 10b can effectively inhibit the NO production in lipopolysaccharides (LPS) stimulated RAW264.7 cells, and it also shows good anti-inflammation effect on mice acute inflammation model of croton oil induced ear edema.

Ratiometric surface-enhanced Raman spectroscopy detection of 5-hydroxyindole-3-acetic acid based on Au@MIL-125@MIPs substrates

Miaomiao Hu,Changchun Wen,Jian Liu,Minzhe Li,Nan Leng,Xiaohuan Guo,Qi Fang,Qinjie Kou,Rong Huang,Xiang-Cheng Lin

5-Hydroxyindole-3-acetic acid (5-HIAA) is a molecular marker that can be used in the early diagnosis of carcinoid tumors, and the development of sophisticated 5-HIAA assays is therefore of great importance. Surface-enhanced Raman spectroscopy (SERS) has been widely used for the rapid and sensitive detection of disease biomarkers. Insufficient specificity for tumor markers and poor spectral reproducibility are the bottlenecks in the practical use of SERS technology. In this study, based on MIL-125 surface-loaded gold nanoparticles (Au@MIL-125), a novel strategy was proposed to obtain Au@MIL-125@molecularly imprinted polymers (MIPs) as functional SERS substrates by wrapping a thin MIP shell around the Au@MIL-125 surface for selective separation followed by a 5-HIAA assay. The Raman peak intensity ratio (I 865 /I 1078 ) was used to quantify 5-HIAA after a SERS spectral calibration with an embedded internal standard (i.e., 4-aminobenzenethiol) to improve the quantitative accuracy. The linear range was from 10 −11 to 10 −7  M, and the limit of detection (LOD) was 5.45 × 10 −13  M. The method of integrating the MIPs with the metal MOF-based nanocomposites was shown to be useful in the analysis of real samples using SERS. The application of SERS for the selective and quantitative detection of analytes in real sample analysis, therefore, has great potential.

A Highly Selective and Fluorescent Turn-on Method for Cu2+ Detection Based on Its Reaction with 3-Carboxyphenylboronic Acid

Miaomiao Tian,Qingwen Zheng,Yuanyuan Pang,Fangjun Wang,Gang Liu

In this study, we developed a novel and facile fluorescent turn-on sensing method for the selective detection of Cu 2+ ions based on the specific oxidative reaction between Cu 2+ ions and 3-carboxyphenylboronic acid (3-CPBA). In this reaction, 3-CPBA was oxidized by Cu 2+ to form 3-hydroxybenzoic acid, which emitted strong fluorescence emission at 412 nm. The resulting product was characterized using comprehensive spectroscopic analyses, including proton nuclear magnetic resonance ( 1 H NMR), carbon-13 nuclear magnetic resonance ( 13 C NMR), and electrospray ionization mass spectrometry (ESI-MS). These analyses confirmed the formation of 3-hydroxybenzoic acid as the primary product. Under optimal conditions, the proposed method could detect Cu 2+ in the range of 0.1–3 µM with a detection limit of 10.2 nM. The developed method exhibited high sensitivity, ease of operation, practicality, and good selectivity toward Cu 2+ over other metal ions. Furthermore, the practical applicability of the method was validated by successfully detecting Cu 2+ in real water samples, with good recoveries of 94.0–105.0%. Graphical A fluorescence turn-on method for Copper ions (Cu 2+ ) detection via oxidative hydroxylation of 3-carboxyphenylboronic acid (3-CPBA) was developed. Under alkaline conditions, Cu 2+ converted non-fluorescent 3-CPBA into highly fluorescent 3-hydroxybenzoic acid (λ ex/e m = 315/412 nm). The method achieved a 10.2 nM detection limit with linear response (0.1–3 µM), superior selectivity over competing metal ions, and validated performance in environmental waters.

2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO•) Radical Scavenging: A New and Simple Antioxidant Assay In Vitro

Xican Li

Current in vitro antioxidant assays have several limitations, which frequently cause inconsistent results. The study develops a new antioxidant assay using the 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•). After the investigation of various factors, the experimental protocol was briefly recommended as follows: PTIO• and the sample solution were added to phosphate buffer (pH 7.4, 50 mM), incubated at 37 °C for 2 h, and then spectrophotometrically measured at 557 nm. The validation test based on 20 pure compounds and 30 lyophilized aqueous extracts suggested that PTIO• scavenging had a good linear relationship, stability, and reproducibility. In the ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, PTIO• was observed to give m/z 234 when encountering l-ascorbic acid. As an antioxidant assay, PTIO• scavenging possesses four advantages, i.e., oxygen-centered radical, physiological aqueous solution, simple and direct measurement, and less interference from the tested sample. It can also satisfactorily analyze the antioxidant structure–activity relationship. PTIO• scavenging has no stereospecificity and is at least involved in H+ transfer.

Design, Synthesis, and Molecular Docking Study of Novel 3-Cyanopyridine Derivatives for the Anti-Cancer Drug Target Survivin Protein

Lu Jia-Hao,Lai Wu-Ji,Jiang Li-He,Lei Fu-Hou,Shen Li-Qun,Wu Ai-Qun

Survivin is an important member of the antiapoptotic protein family and controls the cell’s life cycle. Overexpression of survivin in tumor cells leads to inhibition of apoptosis, thus contributing to cancer cell proliferation. The largest binding pocket in the survivin dimer was located in the BIR domain. The key to the efficacy of 3-cyanopyridines was their surface interaction with the survivin amino acid Ile74. Methods: Through the optimization of the 3-cyanopyridine, 29 new compounds with a 3- Cyanopyridine structure were designed, synthesized, and characterized by NMR, IR, and mass spectrometry. The antitumor activity of the compounds in vitro was detected by the MTT method. Results: In vitro anti-tumor experiments showed that some compounds exhibited good anti-cancer effects. The IC50 values of the compound 2-amino-6-(2,4-difluorophenyl)-4-(4-hydroxyphenyl) nicotinonitrile (10n) against human liver cancer (Huh7), human glioma (U251), and human melanoma (A375) cells were 5.9, 6.0 and 7.2 μM, respectively. The IC50 values of the compound 6-(2,4-difluorophenyl)- 4-(4-hydroxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (9o) against Huh7, U251 and A375 cells were 2.4, 17.5 and 7.2 μM, respectively, which were better than those of 10- hydroxycamptothecin and 5-fluorouracil. Analysis of the results of molecular dynamics simulation established that the BIR domain is the optimal binding site on the survivin protein, and the fingerprints of the eight most active compounds and the molecular docking to the survivin protein are analyzed. Conclusion: 3-Cyanopyridine is an excellent backbone for antitumor lead compounds, 10n and 9o, as derivatives of 3-Cyanopyridine are excellent survivin protein-targeting inhibitors worthy of further study. The key factor in inhibiting survivin protein through the action of amino acid Ile74.

Fabrication of chitosan-coated epigallocatechin-3-gallate (EGCG)-hordein nanoparticles and their transcellular permeability in Caco-2/HT29 cocultures

Hongdong Song,Aijing He,Xiao Guan,Zhengyu Chen,Yize Bao,Kai Huang

Epigallocatechin-3-gallate (EGCG) has gained appreciable attention because of its health benefits. However, the poor permeability across the intestine limits its use. In this study, we have fabricated chitosan-coated EGCG-hordein nanoparticles (Cs-EHNs), with the aim to enhance the intestinal permeability of EGCG. Cs-EHNs were fabricated by layer-by-layer electrostatic stacking method, and its uptake and transcellular permeability were studied in the Caco-2/HT29 co-culture model. The constructed Cs-EHNs had the average diameter of 296 nm, polymer dispersity index (PDI) of 0.30, zeta potential of 59.6 mV, and showed a spherical morphology. Encapsulation efficiency of EGCG was 87.3%. The transcellular permeability experiments indicated that the apparent permeability coefficient (P app ) of Cs-EHNs was higher than that of free EGCG. Furthermore, the cellular uptake of Cs-EHNs was studied by specific endocytosis inhibitors, and results showed that the uptake mechanisms of Cs-EHNs were through caveolae-mediated endocytosis and macropinocytosis. This study demonstrated that encapsulation of EGCG using chitosan-coated hordein nanoparticles could be a promising approach to improve the absorption of EGCG.

Design, synthesis, and biological evaluation of 3-vinyl-quinoxalin-2(1H)-one derivatives as novel antitumor inhibitors of FGFR1

Zhiguo Liu,Shufang Yu,Di Chen,Guoliang Shen,Yu Wang,Leping Hou,Dan Lin,Jinsan Zhang,Faqing Ye

Chlorine-assisted synthesis of CuCo2S4@(Cu,Co)2Cl(OH)3 heterostructures with an efficient nanointerface for electrocatalytic oxygen evolution

Haitao Xu,Dianhua Song,Jiao Li,Yan Zhao,Ruijie Yang,Jingzhe Zhao

The demand for sustainable energy sources urges the development of efficient and earth-abundant electrocatalysts . Herein, chlorine assisted ion-exchange and in-situ sulfurization processes were combined to construct CuCo 2 S 4 @(Cu,Co) 2 Cl(OH) 3 heterostructures from Cu(OH) 2 nanoarrays. Chlorine element in the cobalt source stimulated the formation of (Cu,Co) 2 Cl(OH) 3 precursor, and further facilitated partial transformation of the precursor to CuCo 2 S 4 on the surface to achieve composite structure. The mixed valences of Co element (Co 3+ in CuCo 2 S 4 and Co 2+ in (Cu,Co) 2 Cl(OH) 3 ) and O S interpenetrated nanointerface in the composite catalysts provided low electron transfer resistance for good alkaline oxygen evolution reaction (OER) activities. In 1 mol L −1 KOH electrolyte, the overpotentials of the optimal composite catalyst reached 253 and 290 mV respectively at the current density of 20 and 50 mA cm −2 , which is comparable to the activity of commercial Ir/C (281 mV@20 mA cm −2 ). These findings could provide opportunities for designing effective and inexpensive composite electrocatalysts through nanointerface engineering strategy.

Ultrasensitive photoelectrochemical immunoassay of indole-3-acetic acid based on the MPA modified CdS/RGO nanocomposites decorated ITO electrode

Bing Sun,Lijian Chen,Yan Xu,Min Liu,Huanshun Yin,Shiyun Ai

A novel ultrasensitive photoelectrochemical immunosensor was fabricated based on 3-mercaptopropionic acid stabilized CdS/reduced graphene oxide (MPA-CdS/RGO) nanocomposites for indole-3-acetic acid (IAA) detection. The MPA-CdS/RGO nanocomposites were synthesized by in situ solvothermal growth of triangulated pyramidal CdS nanoparticles on the RGO sheet. 3-Mercaptopropionic acid (MPA) was employed as the modifier and bridge to immobilize the antibody. The nanocomposites were characterized by X-ray diffraction, transmission electron microscopy , scanning electron microscopy and UV/vis spectra. The results showed that the MPA-CdS/RGO nanocomposites revealed enhanced photocurrent response due to excellent electron transport properties of RGO and the improved assembly of CdS nanoparticles onto RGO sheet with the introduction of MPA. Based on the dependence of the photocurrent decline on the concentration of IAA, the proposed photoelectrochemical immunosensor for IAA depicted a linear range from 0.1 to 1000   ng/mL with a lower detection limit (0.05   ng/mL). The high sensitivity, reproducibility and specificity of the method permitted the method suitable to be used in real samples.

Fe3O4@SiO2-CeCl3 Catalyzed Chemoselective Synthesis of Functionalized 3-Substituted-1,5-Benzodiazepines via One-pot Multicomponent and Domino Reactions

Laiyun Zhou,Mingliang Wang,Kaixuan Wang,Tiantian Wen,Lanzhi Wang

Fe 3 O 4 @SiO 2 -CeCl 3 catalyzed chemoselective synthesis of functionalized 3-substituted-1,5-benzodiazepines via one-pot multicomponent and domino reactions has been developed. During the one-pot synthesis process, one new cycle and four new bonds (one C–C, two C–N and one C=C) were constructed by the nucleophilic addition and eliminate reaction (dehydration etc.) process, intramolecular proton transfer and cyclization process. The major advantages of the present method are good to excellent yields, shorter reaction time, simple experimental procedure, easy work up, mild reaction conditions, recyclability of the catalyst and ability to tolerate a variety of functional groups which gives economical as well as ecological rewards.

Insight into the Extreme Side Reaction between LiNi0.5Co0.2Mn0.3O2 and Li1.3Al0.3Ti1.7(PO4)3 during Cosintering for All-Solid-State Batteries

Yaqi Chen,Xieyu Xu,Jianli Cheng,Xuyang Wang,Dawei Wang,Yongjing Wang,XingXing Jiao,Jian Chen,Shizhao Xiong,Zhongxiao Song,Yangyang Liu

All-solid-sate batteries (ASSBs) with a NASICON-type solid-state electrolyte (SSE) of Li1.3Al0.3Ti1.7(PO4)3 (LATP) can be accepted as a promising candidate to significantly improve safety and energy density due to their high oxidation potential and high ionic conductivity. However, thermodynamic instability between the cathode and LATP is scarcely investigated during cosintering preparation for the integrated configuration of ASSBs. Herein, the structural compatibility between commercially layered LiNi0.5Co0.2Mn0.3O2 (NCM523) and LATP SSE was systematically investigated by cosintering at 600 °C. It is noticeable that an extreme side reaction between Li from NCM523 and phosphate from LATP happens during its cosintering process, leading to a severe phase transition from a layered to a spinel structure with high Li/Ni mixing. Consequently, the capacity of NCM523 is lost during the preparation of the NCM523–LATP composite cathode. Based on this, we suggested that the interface modification of the NCM523/LATP interface is valued significantly to inhibit this extreme side reaction, quickening the application of LATP-based ASSBs.

Half-cell and full-cell applications of sodium ion batteries based on carbon-coated Na3Fe0.5V1.5(PO4)3 nanoparticles cathode

Renming Zhan,Bolei Shen,Qiuju Xu,Youquan Zhang,Yushan Luo,Heng Liu,Hao Chen,Feng Liu,Changming Li,Maowen Xu

Pristine Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 and carbon-coated Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 nano-particles are synthesized by one-step solid-phase reaction method. The full battery based on Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 @C nano-particles as cathode and commercial hard carbon as anode outputs a high working voltage about 3.3 V and exhibits superior-rate performance. While the rate increases from 0.5 to 1, 2 and 5 C, the discharge capacity of full battery slightly decreases from 110 to 94, 88, 79 mA h g −1 gradually. Moreover, it shows excellent cycle stability with a capacity retention of 93.8% after 200 cycles at 0.5 C.