Chemical Science
·
2019
·Vol. 10
·期 35
·8179-8186
·
IF 9.556
Xiaohong Pan,Yuehui Zhao,Tingting Cheng,Aishan Zheng,Anbin Ge,Lixin Zang,Kehua Xu,Bo Tang
Reductive stress, the opposite of oxidative stress, represents a disorder in the redox balance state which is harmful to biological systems. For decades, the role of oxidative stress in tumor therapy has been the focus of attention, while the effects of reductive stress have been rarely studied. Here, we report the anti-cancer effects of reductive stress induced by three natural antioxidants (resveratrol, curcumin and celastrol). Considering the fact that the solid tumor microenvironment suffers from hypoxia, we performed cell experiments under hypoxic conditions. In order to observe the reductive stress, we first developed an ultrasensitive fluorescent probe (TCF-MQ) for specifically imaging NAD(P)H which is a marker of reductive stress. TCF-MQ responded to NAD(P)H rapidly and exhibited high sensitivity with a detection limit of 6 nM. With the help of TCF-MQ, we found that upon the treatment of HepG2 cells with pharmacological doses of three natural antioxidants under hypoxic conditions, high levels of NAD(P)H were produced before cell death. The excess NAD(P)H resulted in reductive stress instead of oxidative stress. In contrast, under normoxic conditions, there was no reductive stress involved in the process of cell death induced by three natural antioxidants. Therefore, we hypothesize that the mechanism of cancer cell death induced by natural antioxidants under hypoxia should be attributed to the reductive stress.
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Frontiers in Neurology
·
2019
·
IF 2.635
Zhang Jie,Jiang Yunyao,Liu Nan,Shen Ting,Jung Hyo Won,Liu Jianxun,Yan Bing Chun
Senkyunolide-H (SEH), a major bioactive compound extracted from Ligusticum chuanxiong, has been reported to be effective in preventing cerebral ischemic stroke (CIS). In this study, we employed network pharmacology to reveal potential mechanism of SEH against CIS on a system level and confirmed the therapeutic effects of SEH on CIS by models of cerebral ischemia-reperfusion in vivo and in vitro. Through protein-protein interaction networks construction of SEH- and CIS-related targets, a total of 62 key targets were obtained by screening topological indices and analyzed for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. Gene Ontology analysis indicated that SEH might have a role in treating CIS via regulating some biological processes including regulation of transcription from RNA polymerase II promoter, epidermal growth factor receptor signaling pathway, phosphatidylinositol-mediated signaling, and some molecular function, such as transcription factor and protein phosphatase binding and nitric oxide synthase regulator activity. Meanwhile, the Kyoto Encyclopedia of Genes and Genomes analysis showed that phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was significantly enriched. In addition, our result showed that SEH posttreatment significantly decreased the neurological scores, infarct volume, and neuronal death in the middle cerebral artery occlusion mice. Moreover, the PI3K/Akt/nuclear factor kappa B signaling pathway was activated by intragastric administration of 40 mg/kg SEH, as verified by Western blot. In vitro, treatment of PC12 cells with 100 μM SEH markedly reduced cell death induced by oxygen-glucose deprivation through the activation of PI3K/Akt/nuclear factor kappa B pathway, and the therapeutic effect of SEH was obviously inhibited by 10 μM LY294002. In summary, these results suggested that SEH carries a therapeutic potential in CIS involving multiple targets and pathways, and the most crucial mechanism might be through the activation of PI3K/Akt/nuclear factor kappa B (NF-κB) signaling pathway to inhibit inflammatory factor releases and increase the antiapoptosis capacity. Our study furnishes the future traditional Chinese medicine research with a network pharmacology framework.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Tao Shan,Sunzai Ke,Xin Yang,Xuhui Yang,Bo Weng,Lijuan Shen,Min-Quan Yang
Photocatalytic selective oxidation of aromatic hydrocarbons plays an important role in the production of value-added chemicals. A key step in this process is the activation of C(sp 3 )-H bond by photogenerated holes. However, the inadequate hole generation and lack of surface adsorption-activation sites severely hinders the improvement in photocatalytic C-H bond oxidation. In particular, the random charge migration to the surface impedes the effective capture of holes by surface active sites to dissociate the C(sp 3 )-H bond. Here, we design and fabricate a Co 3 O 4 /Cs 3 Sb 2 Br 9 p-n heterojunction that effectively addresses these challenges. The p-n heterojunction forms strong built-in electric fields (BEF) facilitating spatial charge separation. Holes are accumulated on Co 3 O 4 , while electrons are accumulated on Cs 3 Sb 2 Br 9 , thereby offering abundant active holes and electrons. Moreover, Co 3 O 4 shows stronger adsorption and activation capacity for the C(sp³)-H bond, enabling the C(sp 3 )-H bond dissociation with low reaction energy barrier. Consequently, the holes are directionally extracted from photoactive Cs 3 Sb 2 Br 9 to catalytically active Co 3 O 4 under visible light irradiation, thereby accelerating the toluene oxidation. The optimized 5 % Co 3 O 4 /Cs 3 Sb 2 Br 9 exhibits a benzyl aldehyde (BAD) evolution rate of 5044 μmol g −1 h −1 and a benzyl alcohol (BA) production rate of 1820 μmol g −1 h −1 , which are 12 and 17 times higher than that of blank Cs 3 Sb 2 Br 9 , respectively.
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ENVIRONMENTAL POLLUTION
·
2024
·
IF 7.6
Kuang Wang,Zhanqiang Fang
In the homologous series of polybrominated diphenyl ethers (PBDEs), the debromination of low-brominated diphenyl ethers with higher toxicity remains a challenge. Nano zero-valent iron (nZVI) has been extensively studied for the debromination of PBDEs, but its inherent direct electron transfer mechanism is less efficient for low-brominated diphenyl ethers, and there are issues with high preparation costs. In this work, we synthesize Ni-doped oxalated submicron ZVI (Fe OX bm /Ni) using a low-cost ball-milling method. Fe OX bm /Ni exhibits a debromination rate constant of 0.48 day −1 for 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in tetrahydrofuran (THF)/water. The debromination rate of Fe OX bm /Ni for BDE-47 in water is even faster (0.98 day −1 ), with the yield of the complete debromination product, diphenyl ether, reaching 76.71%. In real groundwater, Fe OX bm /Ni also shows high reactivity toward BDE-47, with a rate constant of 0.33 day −1 . Kinetic experiments, quenching experiments, and degradation pathway indicate that the attack of atomic hydrogen on C-Br bonds is the primary degradation mechanism. Electrochemical analysis further show that Ni 0 sites could cleave hydrogen into absorbed atomic hydrogen (H∗ ABS ) and adsorbed atomic hydrogen (H∗ ADS ), with H∗ ADS playing the main role. These findings contribute valuable insights into advancing the large-scale application of ZVI and offer promising strategies for thorough remediation of PBDEs pollution.
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INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Qiang-Qiang Ma,Peng Zhou,Yizhen Liu,Zuowei Xie
Transition metal catalyzed selective cage B–H functionalization of carboranes has made significant progress in recent years, giving rise to the efficient synthesis of a large variety of cage B-functionalized carboranes including alkenylation, arylation, alkynylation, borylation, hydroxylation, acyloxylation, amination, and halogenation. However, the mechanisms of these catalytic B–X coupling reactions are not well understood. Herein, we describe the isolation and characterization of the catalytically relevant o-carborane based palladium(II) metallacycle, disclosing the details of Pd-catalyzed B–H functionalization of o-carboranes. As a result, highly selective catalytic B(3,6)-dihalogenation, -dimethylation, and -diarylation of o-carboranes have been achieved.
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DRUG DEVELOPMENT RESEARCH
·
2021
·Vol. 82
·期 7
·969-979
·
IF 4.36
Ruixian Xing,Xuewen Liu,Buxian Tian,Yan Cheng,Longguang Li
Parkinson's disease (PD) is a disabling neurodegenerative disease mainly caused by degeneration of mesencephalic dopaminergic neurons in the substantia nigra pars compacta (SNpc). The neuroprotective role of Na + /H + exchangers isoform-1 (NHE1) inactivation in cerebral ischemic damage has been elucidated. The current study aimed to investigate the impacts of NHE1 in PD. In this study, 6-hydroxydopamine (6-OHDA)-induced PD rat models were established to attempt to illuminate the role and underlying mechanisms of NHE1 in SNpc neurons of PD. Meanwhile, nerve growth factor-stimulated PC12 cells followed by 6-OHDA treatment was used to mimic PD in vitro. Results showed that the protein levels of NHE1 were significantly increased in the SNpc neurons of rats and differentiated PC12 cells after 6-OHDA treatment. Inactivation of NHE1 with chemical inhibitor HOE642 suppressed SNpc neuronal loss and NHE1 expression in PD rats. The overlays of tyrosine hydroxylase and NHE1 displayed that NHE1 expression was not colocalized but closely associated with TH. Besides, treatment with HOE642 relieved the dyskinesia, mitochondrial dysfunction, and neuronal apoptosis. Further in vitro evidence confirmed that inhibition of NHE1 by genetic-knockdown prevented mitochondrial dysfunction and apoptosis. Our study represents the first experimental evidence of a potential role for NHE1 in the pathogenesis of PD.
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Journal of Biomedical Nanotechnology
·
2022
·Vol. 18
·期 11
·2484-2497
·
IF 3.641
Li Guiyin,Chen Min,Li Haimei,Li Xinhao,Yao Xiaoqing,Li Liuxun
Golgi protein 73 (GP73) is a novel biomarker for the detection of hepatocellular carcinoma. We prepare a colorimetric aptasensor for GP73 detection based on the catalytic performance of the H-rGO-Mn3O4 nanozyme. The H-rGO-Mn3O4 nanozyme serves
as a peroxidase mimetic which can enhance the reaction with the substrate (3, 3,’ 5, 5′-tetramethylbenzidine, TMB) and H2O2. The peroxidase-like activity of H-rGO-Mn3O4 features a 1.78-fold higher binding affinity value (Km
)
for TMB compared with that of horseradish peroxidase. The H-rGO-Mn3O4 nanozyme not only exhibits admirable peroxidase-like activities due to the synergistic effect of Mn3O4 NPs, rGO and hemin, but also has a large specific surface area to endow the
GP73 aptamer with specific recognition capabilities. A sandwich colorimetric aptasensor is formed to realize the visual detection of GP73 through catalyzing the H2O2-mediated oxidation peroxidase substrate TMB to oxidized TMB accompanied by a color change from colorless
to blue. Under optimal conditions, the logarithm of the GP73 concentration (0.05–50.0 ng/mL) shows a good linear relationship with the absorbance. The calibration equation is Y =−0.0383 lgC+0.4835, with R2 of 0.9964, and the lowest limit of detection is 36.94
pg/mL. Additionally, the content of GP73 in human serum samples is directly detected, and the relative standard deviation is 0.49–4.91%. Compared with the enzyme-linked immunosorbent assay method, the relative error is 0.23–3.61%. All in all, colorimetric aptasensor is demonstrated
to exhibit excellent specificity, stability, and reproducibility.
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JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Guilin Zhou,Xiaodong Zhang,Xin-Long Ni
A water-soluble terpyridine-based cationic fluorescent probe ( SP - TPy ) was synthesized, which emerged with pH-dependent amphiphilicity, resulting in self-assembly and disassembly in aqueous media with the aggregation-induced emission (AIE) property. In neutral water (pH 7.4), a moderate sensing response to Hg 2+ ions was given by the self-assembly of SP - TPy . However, in acidic aqueous media, the monomer of SP - TPy not only appeared to be highly selective and sensitive for Hg 2+ ions, but also displayed highly efficient removal of Hg 2+ ions from solution by rapid precipitation, which was attributed to the coordination-triggered reassembly of SP - TPy . The removal efficiency of SP-TPy f or Hg 2+ was found to be over 99%. Further study indicated that the precipitates were composed of various polyhedral porous frameworks, a property that was further used to adsorb H 2 S gas to form HgS complexes with higher uptake capacities. In addition, SP - TPy can be efficiently regenerated and recycled using a simple treatment with acidic water after adsorption of the H 2 S gas.
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JOURNAL OF ORGANIC CHEMISTRY
·
2018
·
IF 4.805
Chao Zhang,Yugang Song,Zhihui Sang,Lingpeng Zhan,Yu Rao
A strategy combining O- and N-containing directing groups has been developed for the synthesis of 2,2′-biaryl via Pd-mediated C–H bond activation and oxidative coupling. This new transformation may proceed through a mechanism involving Pd(II) and Pd(IV) intermediates. We found the use of PTSA and HFIP to be critical for the reaction and suggest that these reagents could serve as efficient ligands for this C–C bond formation. This methodology provides broad functional group tolerance, excellent reactivity, and high yields.
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Molecular Catalysis
·
2023
·
IF 4.6
Xiangquan Qin,Yiping Jiang,Jie Chen,Fuquan Yao,Longyi Jin,Zhiqi Cong
Selective hydroxylation of C( sp 3 )–H bonds is a long-standing challenge in the organic synthesis field. We herein report an artificial P450 peroxygenase system facilitated by ω-pyridyl fatty acyl amino acids that can hydroxylate broad-spectrum alkanes, including linear and cyclic alkanes and benzylic and allylic alkane chains. Compared with the previously reported dual-functional small molecule (DFSM) with imidazole as a catalytic group (Im-DFSM), pyridyl DFSM (Pyd-DFSM) produced substantially higher total turnover numbers (TTNs) for the hydroxylation of medium-chain alkanes and cycloalkanes (C6–C8), e.g., 12.0-fold and 17.1-fold increased TTNs of P450 mutant F87A/T268V for heptane and cycloheptane , respectively. In addition, Pyd-DFSM altered the enantioselectivity of benzylic hydroxylation, e.g., it almost inverted the configuration observed in the benzylic hydroxylation of ethylbenzene and tetralin . More importantly, Pyd-DFSM showed excellent regioselectivity for allylic hydroxylation over epoxidation of terminal alkenes and cycloalkenes , e.g., up to 94% allylic hydroxylation of 1-hexene was observed. This work significantly enhances the catalytic toolbox of the DFSM-facilitated P450 peroxygenase system; it not only substantially expands the chemical space of P450 enzymes, but also provides an alternative solution for the selective hydroxylation of C( sp 3 )–H bonds.
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Small
·
2021
·Vol. 17
·期 52
·2105643
·
IF 13.281
Bo Liu,Linjuan Zhang,Yuanyuan Luo,Lei Gao,Guotao Duan
The supported metal catalysts on scaffolds usually reveal multiple active sites, resulting in the occurrence of side reaction and being detrimental to the achievement of highly consistent catalysis. Single atom catalysts (SACs), possessed with highly consistent single active sites, have great potentials for overcoming such issues. Herein, the authors used SACs to modulate kinetic process of gas sensitive reaction. The supported Pd SACs, established by a metal organic frameworks-templated approach, promoted greatly the detection capacity to hydrogen sulfide (H 2 S) gas with a very high sensitivity and selectivity. Density functional theory calculations show that the supported Pd SACs not only increased the number of electrons transferring from H 2 S molecules to Pd SACs, but strengthened surface affinity to H 2 S. Moreover, the H S bonds of H 2 S molecules absorbed on Pd atomic sites are more likely to be dehydrogenated directly into sulfur species. Significantly, quasi in situ XPS analysis confirmed the presence of sulfur species during H 2 S detection process, which may be a major cause for such detection signal. Based on these results, a suitable sensing principle for H 2 S gas driven by Pd SACs was put forward. This work will enrich catalytic electronics in chemiresistive gas sensing.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Ge Shu,Yuda Li,Zhuang Wang,Jia-Xing Jiang,Feng Wang
Conjugated polymers have recently emerged as encouraging metal-free photocatalysts for solar energy conversion under visible light irradiation. Unfortunately, photocatalytic activities of the current polymers are still inadequate. Herein, we present a simple but quite attractive conjugated homopolymer (PDBTSO) based a dibenzothiophene-S,S-dioxide moiety. The introduction of sulphonyl group to a polyfluorene-like backbone can cause richly available active sites and lead to the efficient separation of photoexcited charge carriers, thus yielding impressive photocatalytic performance. Furthermore, we explored a natural “phosphorylation” strategy for increasing photocatalytic hydrogen production over PDBTSO. Remarkably, an extremely high hydrogen evolution rate of 44.2 mmol h −1 g −1 was achieved with the optimum addition of K 2 HPO 4 under visible light irradiation.
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