Organic Chemistry Frontiers
·
2021
·Vol. 8
·期 6
·1249-1256
·
IF 5.281
Li-Hua Su,Tian-Ze Li,Chang-An Geng,Yun-Bao Ma,Xiao-Yan Huang,Jin-Ping Wang,Xue-Mei Zhang,Ji-Jun Chen
Two sesquiterpenoid trimers, artematrotrimers A (1) and B (2), and two sesquiterpenoid dimers, artematrodimers A (3) and B (4), possessing unprecedented scaffolds with a methylene-bridged connection were identified from Artemisia atrovirens. Their structures and absolute stereochemistry were determined by comprehensive spectroscopic data, single-crystal X-ray diffraction analyses, and ECD calculations. Compounds 1–4 represent a new type of sesquiterpenoid oligomers featuring the connections between hetero sesquiterpenoid units via one or two C–C bonds. A possible biosynthetic pathway for 1–4 was also proposed. Compound 3 showed obvious cytotoxicity against HepG2 and Huh7 cell lines with IC50 values of 21.9 and 22.6 μM, respectively.
研究领域:
植物化学
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药理学
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肿瘤学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
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2018
·
IF 4.946
Lanxin Luo,Yan Cui,Jinhui Cheng,Bairui Fang,Zongmin Wei,Baoshan Sun
To develop an efficient method for degradation of grape seed and skin proanthocyanidins polymers into oligomers, an optimized sulphurous acid degradation conditions for grape seed with the temperature of 60 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, and for grape skin with the temperature of 40 °C, reaction time of 60 min and sample-sulphurous acid ratio of 1:0.2, were established. Afterwards, HSCCC and prep-HPLC were used to fractionate and isolate individual proanthocyanidin oligomers from the degradation products. Total of ten dimeric or trimeric procyanidins were obtained, and most of them presented high yield (from 0.7 mg to 13.6 mg per run in grape seed and from 0.5 mg to 4.1 mg per run in grape skin) and high purity (over 90%). The proposed method provides a new way for large preparation of oligomeric proanthocyanidins from naturally abundant and wasted polymeric ones.
研究领域:
植物化学
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食品科学
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天然产物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOCONJUGATE CHEMISTRY
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2017
·
IF 4.818
Qin Huang,Jing Xie,Yanpeng Liu,Anna Zhou,Jianshu Li
The fibrillation of protein is harmful and impedes the use of protein drugs. It also relates to various debilitating diseases such as Alzheimer’s diseases. Thus, investigating the protein fibrillation process is necessary. In this study, poly(amido amine) dendrimers (PAMAM) of generation 3 (G3) and generation 4 (G4) were synthesized and conjugated with 4-aminobiphenyl, an aggregation-induced emission (AIE) moiety, at varied grafting ratios. Among them, one fluorescence probe named G3-biph-3 that was grafted average 3.25 4-aminobiphenyl to the G3, can detect the transformations both from native insulin to oligomers and from oligomers to fibrils. The size difference of native insulin, oligomers, and fibrils was proposed to be the main factor leading to the detection of the above transformations. Different molecular weights of sodium polyacrylate (PAAS) were also applied as a model to interact with G3-biph-3 to further reveal the mechanism. The results indicated that PAMAM with a certain generation and grafted with appropriate AIE groups can detect the oligomer formation and transformation during the insulin fibrillation process.
研究领域:
生物化学
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药物化学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULAR MICROBIOLOGY
·
2018
·Vol. 20
·期 6
·e12827
·
IF 4.41
Lian Xu,Zhi-Zhen Pan,Jing Zhang,Li-Yang Niu,Jie Li,Zheng Chen,Bo Liu,Yu-Jing Zhu,Qing-Xi Chen
Cry2Ab, a pore-forming toxin derived from Bacillus thuringiensis , is widely used as a bio-insecticide to control lepidopteran pests around the world. A previous study revealed that proteolytic activation of Cry2Ab by Plutella xylostella midgut juice was essential for its insecticidal activity against P. xylostella , although the exact molecular mechanism remained unknown. Here, we demonstrated for the first time that proteolysis of Cry2Ab uncovered an active region (the helices α4 and α5 in Domain I), which was required for the mode of action of Cry2Ab. Either the masking or the removal of helices α4 and α5 mediated the pesticidal activity of Cry2Ab. The exposure of helices α4 and α5 did not facilitate the binding of Cry2Ab to P. xylostella midgut receptors but did induce Cry2Ab monomer to aggregate and assemble a 250-kDa prepore oligomer. Site-directed mutagenesis assay was performed to generate Cry2Ab mutants site directed on the helices α4 and α5, and bioassays suggested that some Cry2Ab variants that could not form oligomers had significantly lowered their toxicities against P. xylostella . Taken together, our data highlight the importance of helices α4 and α5 in the mode of action of Cry2Ab and could lead to more detailed studies on the insecticidal activity of Cry2Ab.
研究领域:
昆虫学
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分子生物学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Research
·
2023
·
IF 9.9
Li Hanbo,Meng Dejing,Zhang Chenqi,Ji Yinglu,Gao Xinshuang,Hu Zhijian,Wu Xiaochun
Herein, a new strategy is proposed for achieving dynamic chiral controls in self-assembly systems of plasmonic nanorods based on temperature-modulation. Via enlarging Au{100} side facets of Au nanorod (AuNR) building block and changing surface ligand from often-used cetyltrimethylammonium bromide (CTAB) to cetylpyridinium chloride (CPC), inversion of chiroptical signal in side-by-side (SS) oligomers is realized. Under the guide of chiral cysteine (Cys), Au{100} side facet-linked SS rods twist in the opposite direction compared with Au{110} side facet-linked counterparts. At high CPC concentration, by controlling the incubation temperature of chiral Cys, the dominant twist mode can be regulated. Finite-difference time-domain (FDTD) simulations indicate the key role of the twisting dihedral angle of the oligomers in driving chiral signal inversion. At low CPC concentration, a temperature-sensitive chiral switching is observed owing to the conformation change of the CPC ligand layer. The temperature-modulated chiral responses are based on the interactions of chiral molecules, achiral surface ligands, and exposed facets of the building block. The rich dynamic tunability of chiroptical responses of plasmonic assemblies may find applications in stimulus-responsive nanodevices.
研究领域:
纳米技术
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光学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2012
·
IF 3.794
Meiling Liu,Jianhui Deng,Cailang Lai,Qiong Chen,Qiangqing Zhao,Youyu Zhang,Haitao Li,Shouzhuo Yao
Four new conjugated oligo-phenylene-ethynylenes derivatives, N -methyl-4-(4-acetylthiophenylethynyl)-1,8-naphthalimide ( 1 ), thioacetic acid S -[4-(4-aminophenyl-ethynyl)phenyl]ester ( 2 ), 4-methylthiophenylethynylbenzenamine ( 3 ), N -methyl-4-(4-methyl-thiopheny l -ethynyl)-1,8-naphthalimide ( 4 ), were synthesized by Sonogashira and Eglinton cross-coupling reactions. The structures of the four compounds were confirmed by 1 HNMR, 13 CNMR, MS and IR and their spectral characteristics were studied by ultraviolet and visible (UV) spectroscopy as well as fluorescence spectroscopy in different medium. It was found that the fluorescence properties of compounds 2 and 3 were notably improved in aqueous solutions in the presence of β -cyclodextrin ( β -CD). Spectral analysis supported the suppositions that the fluorescence intensity enhancement was due to the formation of inclusion complex with β -CD. The supramolecular interaction was investigated in detail and the reaction mechanism was provided. A salicylaldehyde determination method in aqueous medium was established based on the supramolecular complex of compound 3 . Under the optimum conditions, the supramolecular complex exhibited a dynamic fluorescence response range for salicylaldehyde from 0.6 to 240×10 −6 molL −1 , with a detection limit of 1×10 −8 molL −1 .
研究领域:
有机化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Haixiang Sun,Yuhao Chen,Jiahui Liu,Dingdong Chai,Peng Li,Ming Wang,Yingfei Hou,Q. Jason Niu
Conventional water treatment polyamide nanofiltration (NF) membranes often suffer from the degradation of sodium hypochlorite (NaOCl) in sewage or during the process of membrane cleaning and deteriorate the separation performance, which significantly increases the treatment cost. Herein, a novel polyacrylate composite NF membranes were prepared by interfacial polymerization using oligomeric phenolic resin (OPR) and trimesoyl chloride (TMC) as aqueous and organic phase monomer respectively on the polyethersulfone (PES) ultrafiltration supporting membranes. The fabrication parameters, including the pH of the aqueous solution, reaction time and the concentration of the monomer, on the performance of the composite NF membranes were optimized. A series of characterization indicated that the surface of the NF membranes was negatively charged, the molecular weight cut-off (MWCO) and the pore diameter of the polyacrylate membrane were 400 Da and 0.47 nm, respectively. At the optimized preparation conditions, the NF membrane exhibited high Na 2 SO 4 rejection of 98.2% and water flux of 2.42L·m −2 ·h −1 ·bar −1 , which was superior to most of the polyacrylate NF membranes reported in recent years. Compared with the polyamide membrane, the prepared polyacrylate membrane demonstrated better chlorine-resistant property and still maintained 92.0% Na 2 SO 4 rejection after being treated with NaOCl solution. Moreover, the NF membrane preserved excellent long-term operation stability. The chlorine-resistant NF membrane constructed from OPR monomer has a broad application prospect in the field of high chlorine wastewater treatment.
研究领域:
材料科学
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环境工程
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水处理技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2015
·
IF 1.648
Zhenqian Gu,Fangjie Wang,Haoxiang Lu,Xinling Wang,Zhen Zheng
A new kind of biodegradable poly(urethane-urea)s based on poly-lysine oligomer used as the soft segment was synthesized and characterized. In vitro degradation behavior of poly (urethane-urea)s was investigated, and was assessed by 1H NMR and mass loss. The results indicated that the peptide bonds in poly(urethane-urea)s were effectively cleaved in simulated pancreatic juice containing trypsin, while those in buffer solution without trypsin remained unaffected. The degradability was obviously improved by introducing poly-lysine oligomer into the main chain of poly(urethane-urea)s. The results of cells viability test indicated that the poly (urethane-urea)s showed a good biocompatibility on endothelial cells. The thermostability and hydrophilicity of poly(urethane-urea)s increased with increase in poly-lysine oligomer content.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2017
·
IF 4.162
Ling-Feng Jiang,Bo-Cheng Chen,Ben Chen,Xue-Jian Li,Hai-Lin Liao,Hong-Miao Huang,Zhan-Jing Guo,Wen-Yan Zhang,Lin Wu
A sensitive and stable bioassay for the detection of Aβ oligomer (Aβo), a potentially promising candidate biomarker for Alzheimer's disease (AD) diagnosis, was developed using Fe 3 O 4 magnetic nanoparticles (MNPs) as the recognition and concentration elements and BaYF 5 :Yb,Er upconversion nanoparticles (UCNPs) as highly sensitive labels, conjugated with the Aβo aptamer (DNA1) and the complementary oligonucleotide of the Aβo aptamer (DNA2), respectively. The DNA1 hybridized with DNA2 to form the duplex structure on the surface of the MNPs/UCNPs nanocomposites probe. When the target Aβo was introduced, the aptamer DNA1 preferentially bound with Aβo and caused the dissociation of some complementary DNA2, liberating some UCNP-labeled complementary DNA2 and leading to a decreased upconversion fluorescent intensity on the surface of MNPs. The decreased fluorescence intensity of UCNPs was related to the concentration of Aβo in the range of 0.2–15 nM with a detection limit of 36 pM. The developed method then was successfully applied to measure Aβo in artificial cerebrospinal fluid. Benefiting from the magnetic separation and concentration effect of MNPs, the high sensitivity of UCNPs, as well as the selectivity and stability of the aptamer, the present strategy offered valuable information related to early diagnosis of AD process.
研究领域:
纳米技术
·
生物材料
·
神经科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Ning Xia,Xin Wang,Binbin Zhou,Yangyang Wu,Wenhui Mao,Lin Liu
Amyloid-β oligomers (AβOs) are the most important toxic species in the brain of Alzheimer’s disease (AD) patient. AβOs, therefore, are considered reliable molecular biomarkers for the diagnosis of AD. Herein, we reported a simple and sensitive electrochemical method for the selective detection of AβOs using silver nanoparticles (AgNPs) as the redox reporters and PrP(95–110), an AβOs-specific binding peptide, as the receptor. Specifically, adamantine (Ad)-labeled PrP(95–110), denoted as Ad-PrP(95–110), induced the aggregation and color change of AgNPs and the follow-up formation of a network of Ad-PrP(95–110)-AgNPs. Then, Ad-PrP(95–110)-AgNPs were anchored onto a β-cyclodextrin (β-CD)-covered electrode surface through the host–guest interaction between Ad and β-CD, thus producing an amplified electrochemical signal through the solid-state Ag/AgCl reaction by the AgNPs. In the presence of AβOs, Ad-PrP(95–110) interacted specifically with the AβOs, thus losing the capability to bind AgNPs and to induce the formation of an AgNPs-based network on the electrode surface. Consequently, the electrochemical signal decreased with an increase in the concentration of AβOs in the range of 20 pM to 100 nM. The biosensor had a detection limit of 8 pM and showed no response to amyloid-β monomers (AβMs) and fibrils (AβFs). On the basis of the well-defined and amplified electrochemical signal of the AgNPs-based network architecture, these results should be valuable for the design of novel electrochemical biosensors by marrying specific receptors.
研究领域:
生物医学工程
·
分析化学
·
神经科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2024
·
IF 5.6
Qisheng Luo,Zhili Qiu,Hongqu Liang,Fa Huang,Chen Wei,Jiuying Cui,Zichun Song,Qianli Tang,Xianjiu Liao,Zhao Liu,Jiangbo Wang,Fenglei Gao
α-synuclein oligomer is a marker of Parkinson's disease. The traditional enzyme-linked immunosorbent assay for α-synuclein oligomer detection is not conducive to large-scale application due to its time-consuming, high cost and poor stability. Recently, DNA-based biosensors have been increasingly used in the detection of disease markers due to their high sensitivity, simplicity and low cost. In this study, based on the DNAzyme-driven DNA bipedal walking method, we developed a signal-on electrochemical sensor for the detection of α-syn oligomers. Bipedal DNA walkers have a larger walking area and faster walking kinetics, providing higher amplification efficiency compared to conventional DNA walkers. The DNA walker is driven via an Mg 2+ -dependent DNAzyme, and the binding-induced DNA walker will continuously clamp the MB, resulting in the proliferation of Fc confined near the GE surface. The linear range and limit of detection were 1 fg/mL to 10 pg/mL and 0.57 fg/mL, respectively. The proposed signal-on electrochemical sensing strategy is more selective. It will play a significant role in the sensitive and precise electrochemical analysis of other proteins.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2023
·
IF 12.6
Yuwei Bu,Kun Wang,Xiaoyan Yang,Guangming Nie
As a tumor biomarker, the accumulation of amyloid β oligomers (Aβo) in the brain has been suggested as a key feature in the pathogenesis and progression of Alzheimer's disease (AD). In this work, we designed a novel photoelectrochemical (PEC) and electrochemiluminescence resonance energy transfer (ECL-RET) dual-mode biosensor to achieve ultra-sensitive detection of Aβo. Specifically, the electrode surface modified Carbon Dots (C Dots) and the electrodeposited polyaniline (PANI) film formed a Z-scheme heterojunction reversing the photocurrent signal, and then the Aβo specific recognition peptide was attached to the surface via amide bonding between the amino group of PANI and carbonyl group of peptide. After that, in the presence of CdTe labeled specific recognition aptamer for Aβ (CdTe-Apt), Aβo was captured to construct a sandwich-type biosensor and exhibited a significantly enhanced cathodic photocurrent response because the formed dual Z-scheme heterojunction promoted charge separation efficiency. Interestingly, the proposed biosensor also caused a ratiometric change in the ECL intensity at 555 nm and 640 nm. Therefore, the developed biosensor achieved dual-mode detection of Aβo, where the PEC detection range of Aβo was from 10 fM to 0.1 μM (with a detection limit of 4.27 fM) and the ECL method provided a linear detection range of 10 fM to 10 nM (with a detection limit of 6.41 fM). The stability and reliability of the experimental results indicate that this has been a promising biosensing pattern and could be extended to the analysis of other biomarkers.
研究领域:
生物传感器
·
神经科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）