TALANTA
·
2018
·
IF 4.244
Menglu Li,Juan Yang,Yining Ou,Ying Shi,Li Liu,Chaoqun Sun,Huzhi Zheng,Yijuan Long
The peroxidase-like activity of 2',7'-difluorofluorescein (DFF), was investigated using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate in the presence of H 2 O 2 . DFF could catalyze oxidization of TMB by H 2 O 2 to produce a blue colored oxidation product. Effect of various reaction conditions, such as pH, temperature, H 2 O 2 concentration and reaction time on the catalytic activity of DFF was studied. The peroxidase-like activity of DFF was found to follow Michaelis–Menten kinetics, and its catalysis accorded with ping-pong mechanism. The calculated kinetic parameters (K cat ) of DFF catalysis showed higher peroxidase-like activity than fluorescein and 2′,7′-dichlorofluorescein (DCF). According to the radical capture and electron spin resonance (ESR) spectroscopy results, we confirmed that hydroxyl radical (•OH) is the active specie of catalytic process. It is known that the oxidation of galactose by galactose oxidase (GAOx) enzyme leads to the formation of H 2 O 2 , the H 2 O 2 released in this reaction was consequently quantified using DFF as peroxides mimics and TMB as the chromogen. Thus, a combination of above two reactions was exploited to establish a method for galactose detection. Under the optimum conditions, the linear range of this method was from 10 μM to 20 mM with the detection limit down to 3 μM. Moreover, the developed method was applied to detect galactose in urine samples. Our work will facilitate the utilization of DFF intrinsic peroxidase-like activity in medical diagnostics and biotechnology.
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PubMed
高影响因子
Pharmaceutics
·
2020
·Vol. 12
·期 2
·167
·
IF 4.421
Yu Wang,Xu Bai,Bo Hu,Maochen Xing,Qi Cao,Aiguo Ji,Shuliang Song
Detailed knowledge of the intestinal transport of polymannuronic acid (PM) and polyguluronic acid (PG) is critical for understanding their biological activities. To investigate the transport in the gastrointestinal tract, PM and PG were chemically modified with tyramine and conjugated with fluorescein isothiocyanate (FITC) to synthesize FITC-PM (F-PM) and FITC-PG (F-PG) successfully. The transport mechanisms of F-PM and F-PG across the intestinal epithelial cell monolayers (Caco-2 cell monolayers) were then investigated. The results demonstrated that the transport of F-PM and F-PG into epithelial cells was time- and energy-dependent, which was mediated by the macropinocytosis pathway and the clathrin- and caveolae (or lipid raft)-mediated endocytic pathway. The transport process of F-PM and F-PG in Caco-2 cells depended on the acidification of endosomes and involved lysosomes. Tubulin mediated the transport of F-PM, but not of F-PG. Moreover, the absorption enhancer chitosan (CS) promoted the transport of F-PM and F-PG, increasing the apparent permeability coefficient (Papp) by 1.9-fold and 2.6-fold, respectively, by reversibly opening the tight junction (TJ). In summary, this study provided a comprehensive understanding of the transport of PM and PG in the small intestinal epithelial cells, which will provide a theoretical basis for the development of PM and PG with good intestinal absorption.Keywords:polymannuronic acid;polyguluronic acid;transport mechanisms;Caco-2 cell monolayers
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高影响因子
iScience
·
2023
·
IF 5.8
Yao Li,Zi-Yu Liang,Hai-Lin Wang
Summary Red blood cells supply the oxygen required for all human cells and are in demand for emerging blood-loss therapy. Here we identified N6-methyl-2′-deoxyadenosine (6mdA) as an agonist that promotes the hyperproliferation of burst-forming unit erythroid (BFU-E) progenitor cells. In addition, 6mdA represses the apoptosis of erythroid progenitor cells (EPCs). Combined use of with SCF and EPO enabled cultures of isolated BFU-E to be expanded up to 5,000-fold. Transcriptome analysis showed that 6mdA upregulates the expression of the EPC-associated factors c-Kit, Myb, and Gata2 and downregulates that of the erythroid maturation-related transcription factors Gata1, Spi1, and Klf1. Mechanistic studies suggested that 6mdA enhances and prolongs the activation of erythropoiesis-associated master gene c-Kit and its downstream signaling, leading to expansion and accumulation of EPCs. Collectively, we demonstrate that 6mdA can efficiently stimulate the EPC hyperproliferation and provide a new regenerative medicine recipe to improve ex vivo generation of red blood cells.
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PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Qi Dang,Jiani Chen,Tianbao Li,Long Liu,Tianzeng Huang,Chunya Li,Tieqiao Chen
A palladium-catalyzed decarbonylative annulation of 2-arylbenzoic acids with internal alkynes via C(sp2)–H activation has been developed. A series of phenanthrenes were produced in moderate to good yield with good functional group tolerance. The mechanism study indicated that the C(sp2)–H activation should be the rate-determining step during the reaction.
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高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-15
·
IF 5.228
Zhang Tingjing,Liang Jianqiang,Wang Panxue,Xu Ying,Wang Yutang,Wei Xinyuan,Fan Mingtao
Phloretin-2′- O -glycosyltransferase (P2′GT) catalyzes the last glycosylation step in the biosynthesis of phloridzin that contributes to the flavor, color and health benefits of apples and processed apple products. In this work, a novel P2′GT of Malus x domestica (Md P2′GT) with a specific activity of 46.82 μkat/Kg protein toward phloretin and uridine diphosphate glucose (UDPG) at an optimal temperature of 30 °C and pH 8.0 was purified from the engineered Pichia pastoris broth to homogeneity by anion exchange chromatography, His-Trap affinity chromatography and gel filtration. The purified Md P2′GT was low N -glycosylated and secreted as a stable dimer with a molecular mass of 70.7 kDa in its native form. Importantly, Md P2′GT also exhibited activity towards quercetin and adenosine diphosphate glucose (ADPG), kaempferol and UDPG, quercetin and UDP-galactose, isoliquiritigenin and UDPG, and luteolin and UDPG, producing only one isoquercitrin, astragalin, hyperoside, isoliquiritin, or cynaroside, respectively. This broad spectrum of activities make Md P2′GT a promising biocatalyst for the industrial preparation of the corresponding polyphenol glycosides, preferably for their subsequent isolation and purification. Besides, Md P2′GT displayed the lowest K m and the highest k cat /K m for phloretin and UDPG compared to all previously reported P2′GTs, making Md P2′GT favor phloridzin synthesis the most.
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PubMed
高影响因子
BIODEGRADATION
·
2021
·Vol. 32
·期 1
·99-112
·
IF 3.909
Qiao Weichuan,Miao Jiahui,Jiang Hongmei,Yang Qiwen
Perfluoroalkyl carboxylates (PFCAs) is toxic to the environment and human health. However, the degradation characteristics of fluorotelomer alcohols (FTOHs), precursors of PFACAs biodegradation, in the sludge during aerobic composting remain unclear. In this study, the degradation characteristics of 6:2 FTOH in sewage sludge by composting were researched and the influences of 6:2 FTOH on the composting process and microbial communities of the sludge were evaluated. After 52 days of composting, 6:2 FTOH retained only 0.73% of its original concentration, and its half-life was less than 1 d; 6:2 FTOH was degraded finally to perfluorohex unsaturated acid, perfluoropentanoic acid, 5:3 polyfluorinated acid (FTCA), 4:3 FTCA, and perfluorobutanoic acid through two pathways; and 6:2 FTCA and 6:2 fluorotel unsaturated acid were the intermediate products. Notably, dosing with 6:2 FTOH affected the composting process of sewage sludge. Additionally, 50 mg/kg 6:2 FTOH resulted in a decrease in the microbial richness and diversity of sludge compost. When compared with the compost without 6:2 FTOH, the proportion of Proteobacteria had increased, and the proportion of Firmicutes had decreased as the concentration of 6:2 FTOH increased. The negative effect of a dosage of 50 mg/kg 6:2 FTOH was more obvious than the effect of other treatments. This study expanded our understanding of the risk of sludge contaminated by 6:2 FTOH being used as a fertilizer after composting.
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高影响因子
JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2023
·
IF 2.3
Wei Tian,Jingni Wang,Wen Zhong,Hao Huang,Mingyu Ji,Tingting Yang,Shijie Lin,Shaofeng Chen,Peilin Yang
Two new anthraquinone-organotin complexes [Ph 3 Sn(O 2 CC 14 H 7 O 2 ) · MeOH] · MeOH ( AQS01 ) and Cy 3 Sn(O 2 CC 14 H 7 O 2 ) ( AQS02 ) were synthesized and characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, 119 Sn NMR, X-ray crystallography and thermo-gravimetric analysis. Incorporation of 9,10-anthraquinone with organotin successfully enhanced its anticancer activity. Interestingly, the anti-proliferative activity of AQS01 against CAL-27 cells in vitro was almost 10-fold that of mitoxantrone and 40-fold that of cisplatin. Flow cytometry showed that AQS01 could induce apoptosis and arrest cell cycle in S phase. UV–visible absorption spectrometry and molecular docking showed that AQS01 can be well embedded in the double helix of DNA. Moreover, AQS01 induced cell death by upregulating the expression level of the DNA damage protein γ -H 2 AX and activating the mitochondrial apoptotic signaling pathway (Bax/Bcl-2). Therefore, AQS01 can be used as a potential anticancer drug and has potential for further research.
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高影响因子
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
·
2022
·Vol. 77
·期 7
·715-722
·
IF 1.712
Jinghao Zhuang,Wenlin Feng,Bo Zhou,Qili Zhang,Chong Liu,Yao Gong
A series of CaSr(WO 4 ) 2 : Eu 3+ and CaSr(WO 4 ) 2 : Eu 3+ , Li + phosphors with different Eu 3+ or Eu 3+ /Li + molar contents were successfully synthesized by high-temperature solid-state reaction. Through a series of characterization methods, the composition, structure and luminescence characteristics of the sample are obtained. Upon excitation at 393 nm, the strong red light corresponding to the 5 D 0 → 7 F 2 transition of Eu 3+ can be observed. The effect of Li + charge compensation on the photoluminescence of the sample is studied. The strongest red emission is obtained through 1% Eu 3+ and 1% Li + doping. All of the results indicate that Li + charge compensation can effectively enhance the red emissions intensity of Eu 3+ -doped CaSr(WO 4 ) 2 phosphors.
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高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 3.475
Yu Zhang,Xiaohui Di,Wen Wang,Miaojia Song,Qiang Yu,Zhongming Wang,Zhenhong Yuan,Xiaoyan Chen,Huijuan Xu,Ying Guo
Methyl-2-furoate (MF) is a high-value compound, and can be produced via esterification of furoic acid derived from biobased furfural. Herein, CAL-B and [bmim][PF 6 ] were the most efficient lipase and organic medium for MF production, respectively. Based on mass action law and reaction reversibility, a mathematical model was developed. Data analysis showed the newly proposed binary regression was apparently more suitable compared to the commonly used unitary regression. The enzymatic promotion factor m i for esterification and hydrolysis was 1.8159 and 0, while the alcohol inhibition factor n i was 0 and 0.06436, respectively. Both the activation energy E a, i for esterification and hydrolysis was 84 kJ/mol, and the pre-exponential factor A i was 7.1408×10 13 and 7.8962×10 13 , respectively. Kinetics study demonstrated that CAL-B held significantly more dominant esterification activity compared to hydrolysis activity, whereas alcohol just inhibited hydrolysis activity instead of esterification activity, and the relationship between esterification/hydrolysis rate constants k i and temperature agreed with Arrhenius equation. The maximum MF yield was 82.5 % at 24 h, and the yield decreased to 75.4 % after 1 re-use of CAL-B, but maintained about 20 % for next 4 cycles. Totally, the developed model and binary regression analysis method is ideal for in-depth examination of lipase-catalyzed kinetics in heterogeneous system.
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高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Da-Hua Shi,Xiao-Dong Ma,Zong-Ming Tang,Tong Dong,Bao-Yun Xu,Yu-Wei Liu,Xiao-Kai Song,Wei-Wei Liu,Meng-Qiu Song
Three 2-phenylthiazole derivatives were synthesized, characterized and evaluated as urease inhibitors. The structures of the 2-phenylthiazole derivatives were characterized by FT-IR, 1 H NMR and 13 C NMR spectroscopy. Their crystal structures were also determined by single-crystal X-ray diffraction studies. Hirshfeld surfaces analysis and their associated two dimensional fingerprint plots of compounds were used as theoretical approach to assess driving force for crystal structure formation via the intermolecular interactions in the crystal lattices of synthesized compounds. The study of X-ray single crystal diffraction and Hirshfeld surfaces analysis of the prepared compounds shows N H⋯O hydrogen bonds and C H⋯O intermolecular interactions among molecules of synthesized compounds. The urease-inhibition activities of the synthesized compounds were tested by phenol red method. Among the three compounds, the compound N-cyclohexyl-2-(4-methoxyphenyl)thiazole-4-carboxamide ( 5b ) showed the best urease inhibitory activity with the IC 50 of 1.82 μ M. The docking study performed demonstrated that compound N-cyclohexyl-2-(4-methoxyphenyl)thiazole-4- carboxamide could interact with the catalytic active site of urease.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Yu-Jie Shen,Li-Feng Fang,Yan Yan,Jia-Jia Yuan,Zhi-Qiang Gan,Xiu-Zhen Wei,Bao-Ku Zhu
A metal-organic composite membrane with sub-2 nm pores was developed via interfacial coordination reaction in biphasic systems for the first time. Herein, tannic acid (TA) was dissolved in water, as aqueous phase; iron(III) acetylacetonate (Fe(acac) 3 ), used as Fe(III) source, was dissolved in n -hexane as organic phase. A detailed study was conducted to obtain the defect-free TA-Fe(III) separation layer, including the salt concentration in aqueous solution, pH of the aqueous solution and the ratio of TA to Fe(acac) 3 . The results indicated that the defect-free TA-Fe(III) composite membrane formed when the tris-complex (TA 3 -Fe(III)) was achieved. The optimal condition for preparing TA-Fe(III) composite membrane was using aqueous solution containing 0.4 M NaCl at pH = 6 with the ratio of TA to Fe(acac) 3 of 10. Different from the typical separation layer formed on the membrane surface by interfacial polymerization, the TA-Fe(III) separation layer was formed in the pores of the substrate, which is attributed to the higher diffusion coefficient of Fe(acac) 3 from organic phase to aqueous phase. This work provided a novel strategy to fabricate metal-organic composite membrane with sub-2 nm pores; meanwhile, the new-prepared membrane shows a high Na 2 SO 4 rejection of 97.3% with the water permeance of 8.6 L m −2 h −1 bar −1 , and a high VB 12 rejection of 97.6%, indicating an excellent ion/molecule separation performance.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Yiqun Zhang,Chong Wang,Fengmin Liu,Xiaoying Sun,Xinhao Guo,Lianjing Zhao,Geyu Lu
In recent years, researchers have discovered that self-assembled monolayer functionalized surfaces could improve the gas-sensing performance of semiconductor oxide-based sensors. In the present work, metal-organic framework material ZIF-8 was selected as the self-sacrificial template, and then ZIF-8 materials were calcined at a high temperature to obtain ZnO nanoparticles . Subsequently, the surface of ZnO was modified to install a single layer of 3-aminopropyltriethoxysilane (APTES). In comparison with the pure ZnO-based sensor, the sensor based on 0.5 vol% APTES/ZnO had higher response to 2-butanone. The response has remarkably improved mainly due to APTES molecules capture electrons from the surface of ZnO to widen the electron depletion layer . In addition, the amine (–NH 2 ) group of the APTES monolayer enhanced the specific interaction between the sensing material and 2-butanone, thereby the performance of the sensor was improved. After functionalization with 0.5 vol% APTES, the lower detection limit of the sensor reached as low as 200 ppb, while that of the pure ZnO-based sensor was 500 ppb.
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