Catalysis Science & Technology
·
2019
·Vol. 9
·期 21
·6145-6151
·
IF 5.726
Desheng Yang,Rui Zhang,Ting Zhao,Tingting Sun,Xiaomeng Chu,Shaojie Liu,Erjun Tang,Xiaodong Xu
Due to their small size, uniform dispersion and good stability, dendrimer encapsulated nanoparticles (DENs) are widely used as nanocomposite materials. However, as a commonly used template, the polyamidoamine (PAMAM) dendrimer is limited in the biological and medical fields because of its toxicity. Besides, nanoparticles are commonly encapsulated inside dendrimers, which limits their effective contact with the reactants. In this paper, we presented a comprehensive investigation on the synthesis, characterization and application of 4-carbomethoxypyrrolidone modified polyamidoamine (PAMAM-Pyr) dendrimer–silver nanocomposites (Ag–PPDNCs). The silver nanoparticles were stabilized by PAMAM-Pyr, which combined the advantages of PAMAM and polyvinylpyrrolidone (PVP). Compared with particles prepared with PVP or PAMAM, silver nanoparticles prepared with PAMAM-Pyr had smaller particle sizes with a narrow distribution of 4.78 ± 0.57 nm, which were a kind of mixed type of dendrimer nanocomposite. In addition, Ag–PPDNCs showed a very high activity in the reduction of 4-nitrophenol with an observed rate constant of up to 7.2 × 10−3 s−1 and the turnover frequency was as high as 948.6 h−1, which was superior to that of other reported templates. These results demonstrated the significant role of PAMAM-Pyr in the preparation of Ag–PPDNCs with small particle sizes and excellent catalytic reduction properties. Due to its excellent application performance and low toxicity, PAMAM-Pyr has great application potential in the fields of catalysis and medicine.
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CRYSTENGCOMM
·
2014
·Vol. 16
·期 33
·7667-7672
·
IF 3.858
Tingting Zhang,Yan Yang,Xiaojun Zhao,Jiangtao Jia,Hongmin Su,Hongming He,Jingkai Gu,Guangshan Zhu
The pharmaceutical cocrystal approach can be used to modify the properties of paliperidone. We report here two novel cocrystals, paliperidone 4-hydroxybenzoic acid cocrystal (1, 1 : 1, w/w) and paliperidone 4-aminobenzoic acid cocrystal (2, 1 : 1, w/w), with CCDC numbers of 855981 and 948923, which were constructed using paliperidone with 4-hydroxybenzoic acid and 4-aminobenzoic acid, respectively. The experimental results of the dissolution studies revealed that both 1 and 2 showed much faster dissolution rates than the original active pharmaceutical ingredient (API) in simulated gastric fluid media (pH = 1.2). The pharmacokinetic (PK) studies of 1, 2 and the original API were conducted using beagle dogs. 1 has a slightly higher maximal serum concentration, and both of the cocrystals presented considerably faster absorption rates after a single-dose oral administration to beagle dogs compared to the original API. Observed improvements suggested their potential application to the treatment of acute schizophrenia.
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2015
·
IF 2.947
Xuechen Huang,Hanxing Liu,Zhe Song,Hua Hao,Wenqin Zhang,Qi Xu,Chuyu Peng,Ling Huang,Minghe Cao
Dense (1 − x )BaTiO 3− x (Na 1/4 Bi 3/4 )(Mg 1/4 Ti 3/4 )O 3 [(1 − x )BT– x NBMT] polycrystalline ceramics were prepared by solid-state reaction method. The detailed structure analysis was performed by X-ray diffraction (XRD) and Raman spectroscopy , confirming that the Ba and Ti sites were partially replaced by Na + /Bi 3+ and Mg 2+ ions, respectively. An obvious structural variation from tetragonal to pseudocubic was observed for sample with x = 0.08–0.12. The lattice parameter for sample with x ≥ 0.12 decreased linearly with x value. Three changing modes in frequency, width and intensity were observed with x value in the Raman spectra, indicating intense changes of local structure, accounting for evolved dielectric and ferroelectric macroscopic properties. The subgrain microstructures were observed by conventional transmission electron microscopy (TEM) imaging with an energy-dispersive X-ray spectroscopy (EDS) attachment. A large number of core–shell grains were detected by TEM dark field, for x = 0.20, which were attributed to the dissolution–precipitation mechanism. In this present study, (1 − x )BT– x NBMT ceramics are considered promising for high temperature capacitor applications.
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ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Kang Ma,Qian Tang,Chun-rong Zhu,Jun-fei Long,Cheng-bin Gong,Xiang-kai Fu
This work reports novel dual-colored and fast switching electrochromic materials based on pyridinium salts , 1,1′,1″,1‴-tetrakis(4,4′,4″,4‴-tetrapyridyl)cyclobutane derivatives (TPCBDs). TPCBDs show outstanding electrochromic properties including fast electrochromic switching, dual color, reasonable contrast, low driving voltage, and good stability. TPCBDs are promising candidates for visible electrochromic displays because of their remarkable electrochromic behaviors.
研究领域:
材料科学
·
电化学
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SYNTHETIC COMMUNICATIONS
·
2023
·
IF 2.1
Jun Yang,Guang-Ping Liang,Xiong-Li Liu
To investigate the effects and mechanisms of 4-(1H-indol-1-yl)-4-oxobutanoic acid spliced podophyllotoxin derivatives (3a–3l) on tumor cells. The MTT method was adopted to evaluate (3a–3l) antitumor activity in vitro against A549 cells, A549/DDP cells, MCF-7 cells. The results showed that compound 3l had the most prominent inhibitory effect and high selectivity with IC50 18.53 ± 1.51 µM against A549/DDP cells. Meanwhile, the effects of compound 3l on the nuclear state, cell cycle and apoptosis of A549/DDP cells showed that compound 3l induced apoptosis by delaying the G2/M phase of A549/DDP cell cycle. In addition, molecular docking of compound 3l also showed that it could form a good hydrogen bond with ARG-158 (d = 2.6, 2.7 Å) and HIS-406 (d = 2.5 Å) at the colchicine site of tubulin. Compound 3l could provide lead compound for the development of new multi-drug resistant anti-tumor drugs.
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AUSTRALIAN JOURNAL OF CHEMISTRY
·
2019
·Vol. 72
·期 7
·533-541
·
IF 1.226
Sai Huang,Mei Yang,Xin-Yu Deng,Qian Jiang Zhu,Ying Huang,Zhu Tao,Kai Chen
In the present work, a host–guest system of a hemimethyl-substituted cucurbit[6]uril derived from 3α-methyl-glycoluril (HMeQ[6]) and a hemicyanine dye, trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (t-DSMI) showing strong fluorescence emission has been evaluated as a fluorescent probe. The results of a preliminary systematic study on the detection of a series of inorganic anions have revealed that this Q[n]-based host–guest fluorescent probe shows clear responses to BF4− and H2PO4− anions through distinct fluorescence quenching. Application of this Q[n]-based host–guest interaction system in anion recognition or detection opens a new avenue in Q[n] chemistry.
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GLIA
·
2024
·
IF 5.4
Kechun Chen,Bingtian Xu,Shuqin Qiu,Lu Long,Qian Zhao,Jiangping Xu,Haitao Wang
We have previously shown that phosphodiesterase 4 (PDE4) inhibition protects against neuronal injury in rats following middle cerebral artery occlusion/reperfusion (MCAO/R). However, the effects of PDE4 on brain edema and astrocyte swelling are unknown. In this study, we showed that inhibition of PDE4 by Roflumilast (Roflu) reduced brain edema and brain water content in rats subjected to MCAO/R. Roflu decreased the expression of aquaporin 4 (AQP4), while the levels of phosphorylated protein kinase B (Akt) and forkhead box O3a (FoxO3a) were increased. In addition, Roflu reduced cell volume and the expression of AQP4 in primary astrocytes undergoing oxygen and glucose deprivation/reoxygenation (OGD/R). Consistently, PDE4B knockdown showed similar effects as PDE4 inhibition; and PDE4B overexpression rescued the inhibitory role of PDE4B knockdown on AQP4 expression. We then found that the effects of Roflu on the expression of AQP4 and cell volume were blocked by the Akt inhibitor MK2206. Since neuroinflammation and astrocyte activation are the common events that are observed in stroke, we treated primary astrocytes with interleukin-1β (IL-1β). Astrocytes treated with IL-1β showed decreased AQP4 and phosphorylated Akt and FoxO3a. Roflu significantly reduced AQP4 expression, which was accompanied by increased phosphorylation of Akt and FoxO3a. Furthermore, overexpression of FoxO3a partly reversed the effect of Roflu on AQP4 expression. Our findings suggest that PDE4 inhibition limits ischemia-induced brain edema and astrocyte swelling via the Akt/FoxO3a/AQP4 pathway. PDE4 is a promising target for the intervention of brain edema after cerebral ischemia.
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PubMed
高影响因子
Current Pharmaceutical Analysis
·
2023
·Vol. 19
·期 6
·511-520
·
IF 0.6
Zhang Mengmeng,Zou Qiaogen
Background: Atopic dermatitis (AD) is an allergic skin disease that can be inherited. Crisaborole is a specific drug developed to deal with this disease. The compounds of 4-(4- Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4-bromo-3-formylphenoxy)-3- formylphenoxy) benzonitrile
are the representative impurities in the synthesis of Crisaborole active pharmaceutical in gradient (API). Owing to the genotoxic impurities that could lead to cancer and gene mutations, it is necessary to develop a simple, efficient, sensitive, and accurate method to detect these impurities.
In this study, the 4-(4-Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4- bromo-3-formylphenoxy)-3-formylphenoxy)benzo- nitrile present in Crisaborole API were detected using UPLC-MS/MS. Methods: The separation was made on a ZORBAX Eclipse XDB-Pheny column (4.6 mm ×75mm, 3.5
μm) with the mobile phase of acetonitrile solution containing 0.1% trifluoroacetic acid (A) and water containing 0.1% formic acid (B) in gradient elution mode. Quantification was performed using positive ion electrospray ionization (ESI), and the contents of two compounds were determined
using the multiple reaction monitoring (MRM) modes. Results: The quantitative analytical method was fully validated with respect to linearity (r > 0.9998), sensitivity, precision, accuracy (the average recovery of two impurities was 84.1% to 90.7%), and robustness. Conclusion:
Three batches of samples were detected by UPLC-MS/MS, indicating that the proposed approach was applicable for the quality evaluation of Crisaborole.
研究领域:
药物分析
·
皮肤病学
·
毒理学
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JOURNAL OF MOLECULAR STRUCTURE
·
2012
·
IF 1.634
Fu Liu,Zhongbo Wei,Liansheng Wang,Zunyao Wang
4,4′-Dihydroxydiphenyl ether and 4,4′-oxybis(1-methoxybenzene) are synthesized. Experimental and theoretical studies on molecular structure, infrared spectra (IR), Raman spectra and nuclear magnetic resonance ( 1 H NMR) chemical shifts of the two synthesized compounds have been worked out. All the theoretical results, which are obtained with B3LYP/6-311G(d,p) method by using the Gaussian 09 program, have been applied to simulate molecular structure, infrared, Raman and NMR spectra of the compounds. The compared results reveal that the calculated geometric parameters match well with experimental values; the scaled theoretical vibrational frequencies are in good accordance with observed spectra; and computational chemical shifts are consistent with the experimental values in most part, except for some minor deviations. These great coincidences prove that the computational method B3LYP/6-311G(d,p) can be used to predict the properties of other similar materials where it is difficult to arrive at experimental results.
研究领域:
化学
·
理论计算化学
·
光谱学
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CHINESE CHEMICAL LETTERS
·
2022
·
IF 8.455
Kun An,Jia Gao,Yihang Chen,Jingjing Nie,Yongjin Li,Junting Xu,Binyang Du
A series of linear poly(ethylene oxide)- b -poly(4-vinylbenzyl chloride)- b -poly(4‑ ter t-butylstyrene) (PEO 113 - b -PVBC 130 - b -P t BS x or E 113 V 130 T x ) triblock terpolymers with various lengths x (=20, 33, 66, 104, 215) of P t BS block were synthesized via a two-step reversible addition-fragmentation chain transfer (RAFT) polymerization. The E 113 V 130 T x triblock terpolymers were non-crystalline because the PVBC and P t BS blocks strongly hindered the crystallization of PEO block. The effects of P t BS block length x on the phase structures of E 113 V 130 T x triblock terpolymers were investigated by combined techniques of small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). It was found that with increasing x from 20 to 215, the phase structure of E 113 V 130 T x triblock terpolymers became more ordered and changed from disordered structure , hexagonally-packed cylinder (HEX), hexagonally perforated layer (HPL), to lamellar (LAM) phase structures. Temperature-variable SAXS measurements showed that the HEX, HPL and LAM phase structures obtained for E 113 V 130 T 66 , E 113 V 130 T 104 and E 113 V 130 T 215 by thermal annealing, respectively, were thermodynamically stable in the temperature range of 30–170 °C.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2026
·
IF 5.4
Yanrong Cheng,Chunyang Liu,Xia Guo
Aqueous two-phase system (ATPS) has been considered a green separation system, and its extraction performance in practical applications is related to its selectivity for the target. However, the selectivity of ATPS towards target molecules is not satisfactory so far. Thus, developing selective ATPS is both meaningful and challenging. Calixarenes are biocompatible, and multiple functions can be integrated into a calixarene-based platform. In the present study, we developed selective ATPSs using 4-sulfothiacalix[4]arene sodium (STC[4]) and imidazole ionic liquid ([C n mim]Br). It is found that the [C n mim]Br/STC[4] ATPS exhibits high selectivity towards theobromine, the [C n mim]Br/trisodium citrate/STC[4] and PEG 400/trisodium citrate/[C n mim]Br/STC[4] ATPSs exhibit high selectivity towards vanillin, and the PEG 400/(NH 4 ) 2 SO 4 /[C n mim]Br/STC[4] ATPS exhibits high selectivity towards syringic acid. Therefore, selective ATPSs targeting different bioactive molecules present in nature can be developed by modifying the composition of [C n mim]Br/STC[4]-based ATPSs.
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PROGRESS IN ORGANIC COATINGS
·
2018
·
IF 2.955
Weinan Gong,Xiaoshuang Yin,Ying Liu,Yun Chen,Wenzhong Yang
The inhibitory effects of 2-amino-4-(4-methoxyphenyl)-thiazole (MPT) on mild steel corrosion were evaluated in 0.5 M H 2 SO 4 and 1 M HCl solutions, respectively. From the analysis of potentiodynamic polarization curves and electrochemical impedance spectroscopy, MPT can effectively inhibit the corrosion of mild steel in acidic solutions. Under the optimal conditions, the inhibition efficiency ( η ) was as high as 95% in 0.5 M H 2 SO 4 solution. The inhibition property of MPT was much better than that of the reported corrosion inhibitor 2-amino-4-phenylthiazole (APT). Polarization curves also demonstrated that MPT mainly inhibited the anodic corrosion of mild steel in HCl solution and the cathodic corrosion in H 2 SO 4 solution, respectively. The adsorption of MPT on the surface of mild steel was found to obey Langmuir adsorption isotherm in both acid solutions. Quantum calculations suggest that the addition of electron donor group (−OCH 3 ) endowed the molecule better adsorption ability on mild steel surface. The interaction between protonated MPT and anions on Fe (0 0 1) surface was firstly investigated using molecular dynamic stimulations, and the results showed that with the adsorption of sulfate ions, MPTH + had a superior binding energy on the surface of Fe. The investigation of UV–vis spectrum demonstrated the direct correlation of the experimental data and the theoretical calculations.
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