Catalysis Science & Technology
·
2024
·
IF 4.4
Jinsong Song,Chuanhua Zhou,Xi Chen,Yang Gu,Feng Xue,Qiaqing Wu,Dunming Zhu
Cyanate-mediated epoxide ring-opening by halohydrin dehalogenases (HHDHs) is a promising method for the synthesis of important optically pure 2-oxazolidinones. However, the regio- and stereoselectivity of the naturally occurring HHDHs are still not satisfactory for styrene oxides (SOs). We used a structure-guided semi-rational design to improve the selectivity of HHDHs from Ilumatobacter coccineus (IcHheG), followed by site-saturation and combinatorial mutagenesis of Y18, L103, I104, and N196. The double mutant I104F/N196W showed dramatically improved selectivity toward SOs with excellent regioselectivity (>99 : 1) and stereoselectivity (E > 200), producing the corresponding useful and valuable (S)-4-aryl-2-oxazolidinone and (S)-SO with 98% ee. Moreover, it accepted a wider range of styrene oxides with moderate to excellent selectivity. Analysis of the substrate binding conformations showed that the regio- and stereoselectivity improvement in IcHheG was attributed to an increase of geometric distances to the two carbons and the oxygen atom of the epoxide ring for a single stereoisomer. This study elucidated key structural motifs responsible for regulating the regio- and stereoselectivity of IcHheG, offering theoretical guidance for protein engineering of HHDHs from other organisms.
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MOLECULES
·
2025
·Vol. 30
·期 7
·1643
·
IF 4.6
Dongmei Gao,Lele Shi,Yuhang Huang,Yingmei Lv,Xuan Yang,Zhenting Du
The thiazole heterocycle is one of the most common moieties found in various drugs. Using 2-aminothiazole as the core structure, the amino group was functionalized with an amide. As a result, 30 trisubstituted 2-amino-4, 5-diarylthiazole derivatives were synthesized, with different substitutions introduced at the C2, C4, and C5 positions. The anti-Candida albicansbiological activities of these synthetic compounds on five kinds ofCandida albicansat different concentrations were detected by the microdilution method. In the first round, four derivatives of 2-amino-4, 5-diarylthiazole exhibited moderate anti-Candida albicansactivity. Among them,4a8was chosen to be subjected to a demethylation process. Thus,5a8was synthesized successfully, giving anti-Candida albicansactivity (MIC80= 9 μM) similar to that of a typical antifungal drug, fluconazole. To understand the mechanism of anti-Candida albicans, molecular docking of the most active5a8against four target proteins of anti-Candida albicans,such as glutamine-fructose-6-phosphoamidamitransferase (GFAT), protein kinase (Yck2), heat-shock protein 90 (Hsp90), and lanosterol 14a-demethylase (CYP51) was carried out. Our research will provide an experimental basis and theoretical guidance for the further design of a new aminothiazole-leading pharmaceutical molecule.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2020
·
IF 4.389
Sheng Yan,Ming-Ming Tu,Yun-Ren Qiu
Polysulfone (PSf) membrane is widely employed in blood purification fields, but the blood compatibility of PSf membrane is not adequate. To improve the hemocompatibility of PSf membrane, 4-(chloromethyl)benzoic acid (CMBA) and sulfonated hydroxypropyl chitosan (SHPCS) were grafted onto PSf membrane surface. In our strategy, CMBA was firstly grafted on the PSf membrane surface through the Friedel-Crafts alkylation reaction, and the product was named BAPSf membrane. Then, SHPCS was grafted onto the BAPSf membrane surface by esterification , and the product was named SHPCS-BAPSf membrane. The effects of temperature and reaction time on the productivity of BAPSf and the grafting density of carboxyl and the effects of reaction time on the grafting density of SHPCS grafted onto the BAPSf membrane surface were studied. The SHPCS-BAPSf membranes are investigated by ATR-FTIR, XPS , contact angle measurements and evaluated by blood compatibility in vitro. The results reveal that the hydrophilicity of SHPCS-BAPSf membranes were grealy improved and the evaluation of protein adsorption , hemolysis test, platelet adhesion plasma recalcification time(PRT), activated partial thromboplastin time(APTT), prothrombin time(PT) and thrombin time(TT) confirmed that the SHPCS-BAPSf membranes have remarkable blood compatibility.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wenqi Wang,Fan Feng,Wentao Chen,Dongyun Ma,Jinmin Wang
To solve the problems of liquid electrolytes, such as easy leakage, unsafety, and narrow applicable voltage range, a polyacrylamide (PAM) hydrogel electrolyte with high transparency and ionic conductivity has been developed. With addition of a redox indicator, sodium 4-diphenylamine sulfonate (SDAS), a color-changing SDAS@PAM hydrogel electrolyte was obtained. The integration of the PAM hydrogel and SDAS into one layer enables the electrolyte to achieve reversible color changes between green and colorless in addition to the function of transporting ions. An electrochromic device (ECD) based on the resulting color-changing hydrogel electrolyte was constructed with a configuration of FTO/ [email protected] /WO 3 · x H 2 O/FTO, where WO 3 · x H 2 O film was used as the counter electrode. A reversible color change between the superimposed blue-green color to colorless, a large optical modulation (74.2 %), fast responses (6.3 s for coloration and 11.8 s for bleaching) and a good cyclic stability are achieved. Additionally, the synergistic electrochromic effect of SDAS and WO 3 · x H 2 O can significantly reduce the coloration and bleaching voltages of the ECD. Therefore, our strategy of designing ECDs with a color-changing hydrogel electrolyte utilizing a redox indicator paves the way for developing and constructing more energy-efficient smart windows.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Jin Dong,Yi-Xuan Fu,Bai-Feng Zheng,Meng-Xi Chen,Qiong Chen,Kandegama Wishwajith,Jiangqing Dong,Hong-Yan Lin,Guang-Fu Yang
Mosquito-borne diseases remain a significant global health burden, necessitating innovative vector control strategies. 4-Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors, widely used as herbicides, have been recently explored for their potential to disrupt mosquito tyrosine metabolic pathways, offering a novel approach to mosquito control. This study utilized a structure-based rational design strategy to repurpose existing HPPD inhibitors, such as pyrazole-benzene 2,2-dioxothiadiazole and pyrazole-1,3-isoindolinone hybrids, targeting Aedes aegypti HPPD ( Aa HPPD). Biochemical assays demonstrated that a series of synthesized hybrid compounds exhibited superior inhibitory activity against mosquito-derived HPPD compared to traditional inhibitors, the IC 50 values of compound a9 and compound c14 are 7.70 nM and 53.80 nM, respectively. Crystallographic analysis showed stable inhibitor binding mediated by chelation with metal ions in the active site and π-π interactions with Phe336 and Phe364. C6/36 cell assays further confirmed elevated tyrosine accumulation and significantly affected energy metabolism in the tricarboxylic acid cycle following treatment with the newly designed inhibitors. These findings highlight the potential of repurposed HPPD inhibitors as safe and effective mosquito control agents with novel mechanisms of action.
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JOURNAL OF PHYSICAL CHEMISTRY B
·
2010
·
IF 3.471
Shaoling Song,Naifei Hu
Poly(4-vinylpyridine) (P4VP) films were electropolymerized on a pyrolytic graphite (PG) electrode surface. The cyclic voltammetric (CV) response of ferrocenedicarboxylic acid (Fc(COOH)2) at P4VP film electrodes was very sensitive to the pH and perchlorate (ClO4−) concentration in testing solutions. Fc(COOH)2 was at the “on” state with a relatively large CV oxidation peak current for the films at pH 4.0 but showed the “off” state with significantly suppressed CV response at pH 7.0. The reversible ClO4− concentration-sensitive on−off property of P4VP films toward Fc(COOH)2 at pH 4.0 was also observed. In particular, the influence of pH and ClO4− concentration on the on−off behavior of the system is not independent or separate but synergetic or cooperative, and the electrostatic interaction between the films and the probe plays a predominant role in deciding the pH- and/or ClO4− concentration-dependent behavior for the system. The dual-responsive property of the P4VP films toward Fc(COOH)2 could also be used to control the bioelectrocatalysis of glucose by glucose oxidase. This synergetic-triggered bioelectrocatalysis on the basis of the intelligent interface system may establish a foundation for fabricating novel multiple factor-controllable biosensors based on enzymatic electrocatalysis.
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FOOD AND CHEMICAL TOXICOLOGY
·
2025
·
IF 3.5
Yue Che,Xiaozhu Wang,Qian Li,Xiyi Peng,Zhen Liu,Wenhui Xu,Mei Jing,Ting Wang,Jian Gao,Weiling Wang
A B S T R A C T Exposure to 4-vinylcyclohexene diepoxide (VCD) has been associated to reproductive toxicity, However, the dynamic ovarian function alterations over time in rats and the underlying mechanisms remain unclear. This study investigated the effects of VCD on ovarian function in female Sprague-Dawley (SD) rats on the 25, 60 and 135 days after VCD injection and discovered related mechanisms. Our results showed that VCD had little ovotoxicity on the 25 th day, as no significant changes were observed except for the reduction of preantral follicles. However, on the 60 th day and 135 th day, rats exhibited irregular estrous cycles, abnormal serum sex hormone levels, ovarian morphological damage, decreased primordial and preantral follicles, and increased atretic follicles. We further found that on the 60 th and 135 th day, VCD might exert ovotoxicity by decreasing antioxidant enzyme levels, inhibiting of the Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (NRF2) and PTEN-induced putative kinase 1 (PINK1)/E3 ubiquitin ligase (Parkin) signaling pathway. Interestingly, on the 25 th day, KEAP1/NRF2 and PINK1/Parking signaling pathway were activated. This study provided a wider application in using laboratory rodents as a model of ovarian failure and highlighted that VCD-induced ovotoxicity was linked to the regulation of the KEAP1/NRF2 and PINK1/Parkin signaling pathways.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Yihan Chen,Wanqing Wei,Jianhao Xu,Wei Song,Jian Wen,Guipeng Hu,Xiaomin Li,Cong Gao,Jing Wu
3-Hydroxy-3-methylbutyrate (HMB), an important dietary supplement, can enhance the quality of life for sedentary and elderly people. However, the catalytic efficiency of the pathway enzymes limited the biosynthesis of HMB. Here, we identified an efficient 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) from Bacteroides barnesiae (BbHPPD) that converted l-Leucine (l-Leu) to HMB together with an efficient L-amino acid deaminase (L-AAD) in lab-preserved Proteus mirabilis (PmL-AADQ92A). The regioselective hydroxylation mechanism of the decarboxylated intermediate of 4-methyl-2-oxopentanoic acid (α-KIC) catalyzed by BbHPPD was elucidated for the first time. Structure-guided semirational design of BbHPPD generated a mutant M4. Compared to the wild type, the titer of mutant M4 increased by 254% when using α-KIC as a substrate. Finally, the engineered Escherichia coli 06 strain achieved the HMB titer of 11.6 g/L, a molar conversion of 65%, and a space-time yield of 0.64 g/(L·h) (the highest to date) in 18 h. This study lays the foundation for industrial-scale biosynthesis of HMB.
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JOURNAL OF HAZARDOUS MATERIALS
·
2016
·
IF 4.836
Dan Chen,Huining Zhang,Kai Yang,Hongyu Wang
In this work, 4-aminothiophenol and 3-aminopropyltriethoxysilane were firstly used to functionalize graphene oxide (GO) in order to promote the sorption efficiencies of methylene blue (MB) and copper (Cu 2+ ). Characterization experiments illustrated that sulfydryl group ( SH) and amino group ( NH 2 ) were existed onto 4-aminothiophenol modified GO (GO-SH) and 3-aminopropyltriethoxysilane modified GO (GO-N), respectively. Adsorption isotherm results showed that the maximum adsorption capacities of MB by GO-SH and GO-N were 763.30 and 676.22 mg/g, which was much higher than original GO 455.95 mg/g. For Cu 2+ adsorption, the maximum adsorption capacities by GO-SH and GO-N were 99.17 and 103.28 mg/g, suggesting that the engineered GO exhibited greater Cu 2+ sorption ability than original GO 32.91 mg/g. Both MB and Cu 2+ removal rates increased with pH and adsorbent dosage increased, while the sorption rates weakly reduced with increasing ionic strength. The modification by SH and NH 2 would not only increase the sorption sites, but also cause chelation with heavy metals, and thus improving the sorption capacities of MB and Cu 2+ .
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RSC Advances
·
2016
·Vol. 6
·期 41
·34692-34698
·
IF 3.289
Ling Wang,Qi Sun,Yang Liu,Zhisong Lu
Carbon nanotubes (CNTs) have been employed as supporting materials for the dispersion of gold nanoparticles (AuNPs) to achieve improved catalytic properties. However, the application of CNT–AuNP composites for the evaluation of chlorophenols (CPs) is not reported. Herein, gold nanoparticle/carboxyl functionalized multi-walled carbon nanotube (AuNPs@cMWCNT) nanocomposites were synthesized via an in situ reduction method and further characterized with field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-vis) spectroscopy and X-ray diffraction (XRD). The AuNPs@cMWCNT modified glassy carbon electrode was subsequently prepared as a sensor for the electrochemical detection of 4-chlorophenol (4-CP). The electro-oxidation of 4-CP on the sensor is an adsorption-controlled irreversible process, which undergoes a two-electron and two-proton transfer. Under the optimal conditions, the oxidation peak current was proportional to the 4-CP concentration in the range of 0.3 to 400 μM, with a detection limit of 0.11 μM. The experimental data demonstrate that the sensor has great reproducibility, long-term stability, high specificity and excellent feasibility. The AuNPs@cMWCNT based sensor could be a facile, low-cost and rapid tool for the potential on-line monitoring of 4-CP in practical applications.
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CHROMATOGRAPHIA
·
2021
·Vol. 84
·期 4
·325-333
·
IF 2.044
Shuai Xiaomin,Cai Zhiqiang,Zhao Xinyu,Chen Yujie,Zhang Qian,Ma Ziwei,Hu Junjie,Sun Tao,Hu Shaoqiang
In this work, a novel calix[4]resorcinarene-based ionic liquid (C4RA-2IL) was synthesized, structurally characterized, and statically coated on capillary column as stationary phase for capillary gas chromatography (GC). The column efficiency of the C4RA-2IL column is 3345 plates m −1 , which are determined by n -dodecane at 120 °C. Based on its McReynolds constants, the C4RA-2IL column showed moderate polarity. Particularly, the C4RA-2IL column show high separation performance for a wide range of analytes and some difficult separation of meta/para-isomers. Moreover, it exhibited excellent selectivity for critical aromatic isomers of chloroaniline, bromaniline, iodoaniline, toluidine and xylidine isomers and shows advantageous separation capability over the commercial polysiloxane stationary phase. This work presents a promising future of calixarene-based ionic liquid as a new type of stationary phase in GC separations.
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RSC Advances
·
2016
·Vol. 6
·期 43
·36256-36263
·
IF 3.289
Huiqi Wang,Shigang Wei,Huihui Zhang,Qiong Jia
A functionalized calix[4]arene (alkenyl@C[4]A) was introduced into the poly(butyl methacrylate-ethylene dimethacrylate) monolith inside a capillary to prepare a polymer monolith microextraction (PMME) material (poly(BMA-alkenyl@C[4]A-EDMA)). Various techniques, including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermo-gravimetric analysis, were employed to characterize the synthesized poly(BMA-alkenyl@C[4]A-EDMA) monoliths. A new method was developed for the preconcentration and analysis of bisphenols using PMME coupled with high performance liquid chromatography (HPLC). Under the optimized conditions, the monolithic column afforded acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. The method was applied to the determination of bisphenols in human serum samples with recoveries ranged from 77.6% to 109.7%.
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