Frontiers in Microbiology
·
2022
·
IF 6.064
Wang Chengyong,Chen Xueman,Zhou Ning,Chen Yan,Zhang Alei,Chen Kequan,Ouyang Pingkai
A novel multifunctional chitinase (CmChi3)-encoding gene was cloned from Chitinolyticbacter meiyuanensis and actively expressed in Escherichia coli. Sequence analysis showed that CmChi3 contains two glycoside hydrolase family 18 (GH18) catalytic domains and exhibited low identity with well-characterized chitinases. The optimum pH and temperature of purified recombinant CmChi3 were 6.0 and 50°C, respectively. CmChi3 exhibited strict substrate specificity of 4.1 U/mg toward colloidal chitin (CC) and hydrolyzed it to yield N-acetyl-D-glucosamine (GlcNAc) as the sole end product. An analysis of the hydrolysis products toward N-acetyl chitooligosaccharides (N-acetyl COSs) and CC substrates revealed that CmChi3 exhibits endochitinase, N-acetyl-β-d-glucosaminidase (NAGase), and transglycosylase (TGase) activities. Further studies revealed that the N-terminal catalytic domain of CmChi3 exhibited endo-acting and NAGase activities, while the C-terminal catalytic domain showed exo-acting and TGase activities. The hydrolytic properties and favorable environmental adaptations indicate that CmChi3 holds potential for commercial GlcNAc production from chitin.
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JOURNAL OF COORDINATION CHEMISTRY
·
2021
·
IF 1.751
Hanyuan Zhang,Xiaomeng Li,Qin Wang,Jiaxin Zhong,Liang Zhao,Xinlong Wang,Chao Qin
Two new coordination polymers constructed from 5-sulfoisophthalic acid sodium salt (NaH2SIPA) and Co or Cu cations, [Co3(SIPA)2(4,4′-bpy)4(H2O)6]·4H2O (1) and [Cu6O3(HSIPA)3(4,4′-bpy)6(H2O)3]·7H2O (2), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), IR spectroscopy, thermogravimetric analysis, UV-Vis spectroscopy, and elemental analysis. Compound 1 represents a twofold-interpenetrating 3-D framework based on Co, SIPA, and 4,4′-bipyridine ligands with a qzd topology. Different from 1, compound 2 shows a 3-D self-penetrating framework based on Cu, HSIPA, and 4,4′-bipyridine ligands. Furthermore, the photocatalytic performance in reduction of CO2 of 1 under visible light was investigated.
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Food & Function
·
2020
·Vol. 11
·期 12
·10852-10863
·
IF 4.171
Mingbao Gu,Jie Jin,Chenghao Ren,Ximiao Chen,Weiyang Gao,Xiangyang Wang,Yaosen Wu,Naifeng Tian,Zongyou Pan,Aimin Wu,Yifei Zhou,Xiaolei Zhang
As an ordinary joint vestigial disease, osteoarthritis (OA) contributes to a considerable proportion of disability cases worldwide. Inflammation, as the main pathological factor, mediates the occurrence and development of OA. Akebia Saponin D (ASD), also known as Asperosaponin VI, is one of the active components extracted from Dipsaci Radix and is rich in Dipsacus loose tea. It has shown sound therapeutic effects on various diseases; nevertheless, its role in OA therapy is not completely understood. This study demonstrated the anti-inflammatory activity of ASD in OA through a series of in vivo and in vitro experiments. In vitro experiments revealed that ASD might prohibit the production of inflammatory mediators in IL-1β treated chondrocytes such as COX-2, iNOS, NO, PGE2, IL-6, and TNF-α. Meanwhile, it may also inhibit the production of ADAMTS-5 and MMP13 and promote the production of Aggrecan and Collagen II. The mechanism study demonstrated that ASD exerted an anti-inflammatory effect by activating the NRF2 target, upregulating the expression of HO-1, and preventing P65 from binding to DNA. In vivo experiments demonstrated that ASD might improve the progression of OA in a DMM mouse model. These research results provide evidence for the potential application of ASD in OA therapy.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 18
·50320
·
IF 2.52
Airong Xu,Fen Wang,Luwei Zhang,Xingmin Xu,Zhihong Xiao,Rukuan Liu
Polymer materials based on fossil resources have brought great convenience to various industries. However, environmental pollution is becoming increasingly conspicuous due to their difficult degradation in nature. Therefore, biodegradable composites are highly desired. In the present work, a simple and feasible preparation approach was presented to fabricate biodegradable and biocompatible composite films including methylcellulose/poly( d , l -lactide-co-glycolide) (MC/PLGA) and methylcellulose/poly(1,4-butylene succinate) (MC/PBS). The effects of MC/PLGA and MC/PBS mass ratios on the morphology, crystalline state, mechanical properties and thermal stability of the composite films were systematically investigated. At the same time, the influence of thermal compression treatment on mechanical properties (tensile strength and elongation) and the cyclic utilization of the composite films were also estimated. The composite films displayed enough good mechanical properties, re-usability and thermal stability.
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MOLECULES
·
2020
·Vol. 25
·期 22
·5391
·
IF 3.267
Zheng Liu,Ming Bian,Qian-Qian Ma,Zhuo Zhang,Huan-Huan Du,Cheng-Xi Wei
A series of novel synthetic substituted benzo[d]oxazole-based derivatives (5a–5v) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer’s disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ25-35-induced PC12 cells at 5 μg/mL. We found that compound5cwas non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ25-35-induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound5cpromoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ25-35-induced PC12 cells. In addition, our findings demonstrated that compound5cprotected PC12 cells from Aβ25-35-induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound5cshows less toxicity than donepezil in the heart and nervous system of zebrafish.Keywords:synthesis;benzo[d]oxazol;thiadiazoles;Alzheimer’s disease;β-amyloid;Akt/GSK-3β/NF-κB signaling pathway
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Congshu Feng,Yun Chen,Jun Shao,Haoqing Hou
Blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) would produce polylactide stereocomplex crystallites (PLA SC). In the PLLA/PDLA specimens prepared by solution mixing or melt blending, the isomeric polymers were mixed in the molecular level. When the distance of these isomers increased, the crystallization behaviors of PLLA/PDLA were not clear yet. In this study, PLLA/PDLA blends were prepared by different electrospinning methods, i.e., spinning by mixed solution (DL-A), side-by-side mode (DL-B), and double spinnerets (DL-C). Results revealed that the distances between isomeric molecules increased in the order of DL-A, DL-B, and DL-C, and this distance influences the phase transition and subsequently crystallization behaviors. In the DL-A, the homochiral crystallites (HC) developed at first, and then SC formed in the specimen with lower content of PDLA. The formation of SC was observed at first, and less or no content of HC was developed with higher content of PDLA. For the DL-B group, the formation of HC was observed at ∼100 °C, and the SC were produced around 140 °C irrespective of composition. More content of SC was produced during or after melting of HC. When referring to the DL-C group, the HC developed at the first stage, and the SC were produced during or after melting of PLA HC. In addition, the SC that developed in the three groups have different nucleation efficiencies for the subsequent formation of HC. The nucleation efficiency increased in the order of DL-A < DL-B < DL-C, and these results hinted that not only the content but also the distribution of SC affects the formation of HC.
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GOLD BULLETIN
·
2020
·Vol. 53
·期 2
·55-62
·
IF 1.706
Li Degui,Luo Yujia,Lan Jiaxin,Luo Zhihong,Li Fujie,Luo Kun
Ligand exchange was triggered at toluene/water emulsion interface between homogeneous gold nanoparticles (Au NPs) with triphenylphosphine (PPh 3 ) and D-penicillamine (D-PA), resulted in amphiphilic Janus Au NPs with both phosphine and thiolate ligands. TEM and XRD analyses indicate that the product is composed of Au nanocrystals in an average diameter of about 3.7 nm. XPS, FTIR, Raman, and 1 H NMR analyses demonstrate that the Au NPs are protected with hydrophilic D-PA molecules and lipophilic PPh 3 ligands in a molecular ratio of ca. 1.8. The NOESY analysis and contact angle measurement further suggest that the D-PA and PPh 3 molecules are spontaneously separated to form compartmentalized hydrophilic and lipophilic regions on the individual Au NPs, which exhibit good catalytic performance and recyclability on the reduction of 4-nitrophenol. The results demonstrate that amphiphilic Janus Au NPs can be synthesized by partly exchange of PPh 3 with D-PA at toluene/water emulsion interface and are potentially applicable for other phosphine/thiolate pairs to modify Au NPs.
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Heliyon
·
2023
·Vol. 9
·期 9
·e19889
·
IF 4
Zhou Chen,Yimei Shen,Run Wang,Siting Li,Yingmin Jia
A novel gene ( BbFFase9 ), with an ORF of 1557 bp that encodes β-d-fructofuranosidase from Bifidobacteriaceae bacterium , was cloned and expressed in Escherichia coli . The recombinant protein (BbFFase9) was successfully purified and showed a single band with a molecular mass of 66.2 kDa. This was confirmed as a β-d-fructofuranosidase and exhibited a high specific activity of 209.2 U/mg. Although BbFFase9 was a soluble protein, it exhibited excellent tolerance to proteases such as pepsin, trypsin, acidic protease, neutral protease and Flavourzyme®, indicating its potential applicability in different fields. BbFFase9 exhibited typical invertase activity, and highly catalyzed the hydrolysis of the α1↔2β glycosidic linkage in molecules containing fructosyl moieties but with no detectable fructosyltransferase activity. It was optimally active at pH 6.5 and 50 °C and stable between pH 6.0 and 9.0 at a temperature of up to 45 °C for 30 min BbFFase9 could also effectively hydrolyze galacto-oligosaccharides, which are a flatulence factor in soybean meal, thus releasing new types of product such as melibiose and mannotriose, or degrading them into invert sugars, the sweeter fructose and glucose. This study is the first to report the application of this type of β-d-fructofuranosidase.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Tao Yu,Ruqiu Ding,Fan Quan,Zhiyuan Ni,Xuanwen Liu,Yan He,Wenning Mu,Xuefei Lei,Yuhan Mo
The development of high activity catalysts with excellent durability is a great challenge to realize the industrialization of electrolytic water oxygen evolution. In this work, Ag nanoparticles modified cross column nickel-iron hydroxyl oxide system (NiFeAg) nanocomposites were synthesized by a two-step strategy. Through XPS spectrum, Tafel slope, and EIS electrochemical impedance spectroscopy, it was found that Ag mainly plays a conductive role, accelerates charge transfer, and adjusts the surface electronic structure, to improve the activity of the catalyst. Impressive is the overall hydrolysis performance, with a current density of 10 mA cm −2 achieved at an overpotential of 211 mV, which shows better performance than other catalysts reported in the literature. Finally, through the theoretical calculation of the determination steps of adsorption energy and rate of oxygen-containing intermediates, it is determined that the active center of the catalyst is mainly Ni site. According to the theory of D-band center, Ag can effectively adjust the D-band center, thereby adjusting the adsorption strength of Ni sites on the surface of NiFe catalyst to adsorbent, and finally improving the OER performance of the catalyst.
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JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Rui Shi,Pengcheng Hao,Zhongzhi Wang,Juan Zhang,Bo Li,Leijun Shen,Xin Qiao
In this work, we prepared a Carbazole-Benzene-Tripyridine ligand with a d -π-A structure and synthesized its corresponding Eu (III) and Tb (III) complexes. The structures of the complexes were analyzed by single crystal X-ray diffraction. It was surprisingly that the fluorescence emission intensity of the Eu(III) complex increases significantly once the solvent was added, indicating that the fluorescence could be activated by the solvent. However, it was confirmed that in the solid state, the complex molecules in the lattice were orderly arranged and there was a π-π stacking effect. The π-π stacking caused strong intermolecular interactions leading to emission quenching. The addition of solvent broke the π-π stacking and enhanced the fluorescence of the Eu(III) complex. The color of the fluorescence emission of the Eu(III) complex depended on the kind of added solvent. The results of nuclear magnetic resonance (NMR) and density functional theory (DFT) calculations suggested that the rotation of the C C single bond in the d -π-A structure ligand in different solvents caused a change in the spatial angle between the carbazole-benzene unit and the tripolypyridine unit in the ligand, thereby changing the excited state energy of the ligand. Hence, the varied emission colors of the complex reflect differences in the energy transfer efficiency of the ligand to rare earth ion. The solvent effect of the Eu(III) complex was then successfully applied in the rapid identification of specific alcohols.
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Small
·
2023
·Vol. 19
·期 37
·2301085
·
IF 13.3
Guo Liu,Qi Zeng,Xinyi Sui,Shuhao Tian,Xiao Sun,Qingfeng Wu,Xijuan Li,Yuhao Zhang,Kun Tao,Erqing Xie,Zhenxing Zhang
Polysulfide shuttle effect and sluggish sulfur reaction kinetics severely impede the cycling stability and sulfur utilization of lithium-sulfur (Li-S) batteries. Modulating d-band electronic structures of molybdenum disulfide electrocatalysts via p/n doping is promising to boost polysulfide conversion and suppress polysulfide migration in lithium-sulfur batteries. Herein, p-type V-doped MoS 2 (V-MoS 2 ) and n-type Mn-doped MoS 2 (Mn-MoS 2 ) catalysts are well-designed. Experimental results and theoretical analyses reveal that both of them significantly increase the binding energy of polysulfides on the catalysts’ surface and accelerate the sluggish conversion kinetics of sulfur species. Particularly, the p-type V-MoS 2 catalyst exhibits a more obvious bidirectional catalytic effect. Electronic structure analysis further demonstrates that the superior anchoring and electrocatalytic activities are originated from the upward shift of the d-band center and the optimized electronic structure induced by duplex metal coupling. As a result, the Li-S batteries with V-MoS 2 modified separator exhibit a high initial capacity of 1607.2 mAh g −1 at 0.2 C and excellent rate and cycling performance. Moreover, even at a high sulfur loading of 6.84 mg cm −2 , a favorable initial areal capacity of 8.98 mAh cm −2 is achieved at 0.1 C. This work may bring widespread attention to atomic engineering in catalyst design for high-performance Li-S batteries.
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LIFE SCIENCES
·
2023
·
IF 6.1
Haijie Wu,Xiaohu Shi,Yingda Zang,Xiaodi Zhao,Xikun Liu,Weida Wang,Wenying Shi,Clarence T.T. Wong,Li Sheng,Xiaoguang Chen,Sen Zhang
Aims Cisplatin is a widely-used drug in the clinical treatment of tumors, but kidney nephrotoxicity is one of the reasons that limits its widespread use. We previously found that 7-hydroxycoumarin-β-D-glucuronide (7-HCG) was one of metabolites of skimmin and highly enriched in the kidneys and maintained a high blood concentration in skimmin-treated rats. Therefore, we investigated whether 7-HCG has a protective effect on cisplatin-induced acute kidney injury. Materials and methods Male C57BL/6 mice were continuously administered 7-HCG for five days, and on the third day, an intraperitoneal injection of cisplatin was given to induce acute kidney injury. After 72 h, the mice were sacrificed for analysis. Serum and renal tissue were collected for renal function evaluation. RNA sequencing was used to explore mechanism, and further validated by western blot and immunohistochemistry. In addition, pharmacokinetic study of oral 7-HCG administration was performed to examine how much 7-hydroxycoumarin (7-HC) was metabolized and 7-HC possible effect on renal protection. Key findings 7-HCG significantly reduced serum BUN and SCR levels, and alleviated pathological damage in renal tissue, and reduced the renal index. RNA sequencing revealed that 7-HCG could reverse p38 MAPK regulation and apoptosis. By western blotting, it was found that 7-HCG could reduce renal injury by reducing p-p38, p-ERK, p-JNK, cleaved-caspase3 and Bax. The immunohistochemical results of cleaved-caspase3 were consistent with western blotting. 7-HCG also significantly reduced the production of ROS in kidney tissue. Pharmacokinetic experiments have shown that 7-HCG in the blood increased rapidly and was eliminated slowly, with an average t 1/2β of 18.3 h. And the concentration of 7-HCG in the target organ kidney was about 4 times higher than that in blood. Significance Our findings indicate that 7-HCG could exert its protective effect against cisplatin-induced acute kidney injury by inhibiting apoptosis via p38 MAPK regulation and elucidates its pharmacokinetics.
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