APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2016
·Vol. 180
·期 2
·210-227
·
IF 1.606
Cao Yingying,Deng Dun,Sun Aijun,Zhang Yun,Hu Yunfeng
Chiral 2-chloropropanoic acids and their ester derivatives are crucial intermediates in the synthesis of many chemicals, especially herbicides. The enzymatic synthesis of chiral 2-chloropropanoic acids and their ester derivatives by esterases was not easily achieved, because the structural difference between the two enantiomers was too small to be recognized by esterases. Herein, we report the expression and functional characterization of one novel low temperature-resistant esterase EST12–7 identified from the genome of Pseudonocardia antitumoralis SCSIO 01299 isolated from the sediments of the South China Sea. Biocatalyst EST12–7 could hydrolyze racemic methyl 2-chloropropinate and generate optically pure ( R )-methyl 2-chloropropinate with high enantiomeric excess (>99 %) and conversion (>49 %) after process optimization. Notably, the addition of different surfactants and using surfactants of different concentrations in the kinetic resolution catalyzed by EST12–7 could greatly affect the enantiomeric excess and conversion rate of product ( R )-methyl 2-chloropropinate.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Xiaogan Zhao,Tao Lin,Wenkai Jiang,Yihan Lin,Luyao Xiao,Yufang Tian,Kai Ma,Changliang Zhang,Feng Ji,Ghahvechi Chaeipeima Mahsa,Xin Rui,Wei Li
Lactobacillus helveticus LZ-R-5 (R-5), a strain with high epithelial adhesion and bioactive exopolysaccharide production, was isolated from Tibetan kefir grains. This study investigated its potential to alleviate intestinal inflammation using a DSS-induced colitis model in BALB/c mice. We integrated microbial diversity and serological analyses to assess changes in gut flora and cytokines following the R-5 treatment. Pathological assessments showed that R-5 reduced crypt distortion in the proximal colon and mitigated hepatic immune challenges by enhancing gut barrier function. The increased relative expression of TGF-β1 and the downregulation of NLRP3-related inflammatory factors were conducive to preventing organ damage in the thymus and spleen of mice with colitis. Additionally, R-5 stimulated GPR43 expression and improved epithelial nutrition, promoting mucin production to prevent enterotoxin leakage. It also modulated the gut microbiota by suppressing Bacteroides and Erysipelatoclostridium, leading to a microbiota composition more akin to that of normal flora.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Si Duan,Yuan Gao,Guihong Lan,Haiyan Qiu,Bo Xu,Xiangming Liu,Ming Zhang,Yusong Chen
Functionalization of ligands is an effective strategy to enhance the adsorption performance of adsorbents. In this study, MIL-101(Fe)-R (R = -H, –OH, –NH 2 , and –NO 2 ) was selected as a platform for systematically studying the impact of functionalization on the adsorption behavior of chlortetracycline (CTC). A series of characterizations were conducted on the prepared MIL-101(Fe)-R to clarify the influence of organic linkers on the microscopic morphology, pore structure, and surface functionality of the adsorbents. Additionally, the effects of different functional groups on the adsorption behavior of MIL-101(Fe)-R were compared to screen for MOFs with high efficiency in removing CTC. Experimental results showed that the maximum adsorption capacities (q m ) of MIL-101(Fe), MIL-101(Fe)–NH 2 , MIL-101(Fe)–OH, and MIL-101(Fe)–NO 2 were 418.980 mg/g, 559.854 mg/g, 187.387 mg/g, and 154.131 mg/g, respectively. Among them, MIL-101(Fe)–NH 2 exhibited a higher mass transfer rate (reaching equilibrium in 15 min). Based on apparent adsorption behavior, adsorption kinetics, isotherm and thermodynamic studies, as well as FTIR and XPS characterizations before and after adsorption, the performance modulation mechanism of MIL-101(Fe)-R in CTC adsorption was discussed in detail. Combined with density functional theory (DFT) calculations, the host–guest interaction controlling the adsorption behavior was understood at the molecular level, demonstrating the optimal binding sites of the adsorbents. This study provides guidance for the design of efficient MOF adsorbents for antibiotic wastewater treatment.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Chengmin Hou,Weimin Yan,Hanxiao Ma,Yuan Bai,Zhiting Yuan
Heavy metal ion (Cu(II)) wastewater will do great harm to human body and environment, and the adsorption materials used in traditional adsorption methods are easy to hydrolyze, resulting in secondary pollution to water. In this paper, an adsorption material poly(glycidyl methacrylate-random-hydroxyethyl methacrylate) grafted ferric oxide@starch (St/Fe 3 O 4 - g -p(GMA- r -HEMA)) was prepared, which had epoxy and hydroxyl group , easy to produce crosslinking, reduce the sensitivity of starch to pH and prevent hydrolysis. Infrared spectroscopy (FTIR), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and magnetometer (VSM) were used to characterize the structure and morphology of the adsorbent. The adsorption properties of the adsorbent for removal of Cu(II) ions were studied via changing the experimental conditions, including the amount of adsorbent, Cu(II) ions solution concentration, pH value, adsorption time, adsorption temperature and so on. Under the optimal adsorption conditions of pH value 7, initial Cu(II) concentration 20 mg/L and adsorption time 160 min, the maximum unit adsorption capacity of St/Fe 3 O 4 - g -p(GMA- r -HEMA) was 94.15 mg/g, and the adsorption performance was good. The adsorption process followed Langmuirm model and second-order kinetic model , and was dominated by chemisorption . The thermodynamic model showed that the adsorption process of St/Fe 3 O 4 - g -p(GMA- r -HEMA) was endothermic. After 8 adsorption cycles, 93.5% of the first adsorption effect can still be retained, and the renewable performance had been improved.
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Catalysis Science & Technology
·
2020
·Vol. 11
·期 1
·297-311
·
IF 5.721
Xiaoqiang Zhang,Peifang Yan,Bin Zhao,Z. Conrad Zhang
The electronic and structural differences of anatase TiO2 (TiO2-A) and rutile TiO2 (TiO2-R) supported Ni catalysts are studied to understand the distinctively different catalytic pathways in guaiacol hydrodeoxygenation over Ni/TiO2-A and Ni/TiO2-R catalysts. Temperature programmed reduction profiles of NiO/TiO2-A and NiO/TiO2-R reveal two types of metal–support interactions. NiO on TiO2-R requires much higher temperature to reduce than NiO on TiO2-A by hydrogen reduction. Surface TiO2-A is partially reduced together with NiO at low temperature driven by strong interaction between reduced Ni and the reducible TiO2-A surface. In situ X-ray photoelectron spectroscopy (XPS), high resolution TEM (HRTEM), and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy of adsorbed CO reveal two types of reduced Ni species on Ni/TiO2-A: Ni0 particles and atomically dispersed electron-rich Niδ− atoms. While Ni0 particles are formed only at high Ni loadings, they are fully encapsulated by an overlayer of partially reduced TiOx, making the surface of Ni particles totally inaccessible to CO and to reactants. The electron-rich Niδ− atoms are favorably formed at all Ni loadings on the TiO2-A surface and show only linearly adsorbed CO in the DRIFT spectra. Electron transfer from Ti and O on the TiO2-A surface to atomically dispersed Ni is indicated by the observation of dominant electron-rich Niδ− species in conjunction with Ti(4+δ)+ and O(2−δ)− on Ni/TiO2-A following H2 reduction. In contrast, the chemical states of metallic Ni0 and Ti4+ remain unchanged on Ni/TiO2-R after H2 reduction. The atomically dispersed Niδ− species, formed only on the Ni/TiO2-A surface, is proposed as the active site responsible for the selective hydrodeoxygenation of guaiacol to phenolics. In contrast, the metallic Ni0 particles formed on the Ni/TiO2-R surface catalyze the typical catalytic hydrogenation, preferentially saturating the aromatic ring.
研究领域:
化学
·
材料科学
·
催化反应
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·
IF 6.7
Xinjun Yu,Zhaoxia Qian,Zhichao Tu,Mingpeng Zhou,Yuxiang Sun,Xin Liu,Zhao Wang,Yinjun Zhang
(R)-N-(2,6-dimethylphenyl) aminopropionic acid methyl ester ((R)-DMPM) is a key chiral intermediate for the fungicide N-(2,6-Dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester ((R)-Metalaxyl). The biological function of the (R)-Metalaxyl is heavily dependent on its R-configuration, however, conventional chemical or single-esterase esterification for (R)-DMPM production induces severe racemization, dramatically compromising the optical purity and the efficacy of (R)-metalaxyl. In this study, a novel dual-enzyme cascade immobilized on polystyrene resin, combining the esterase PAE from Pseudochrobactrum asaccharolyticum WZZ003 for stereoselective hydrolysis of the substate (R,S)-(DMPM) to produce (S)-DMPM and (R)-MAP-acid, and the Novozym 435 for transmethylation of (R)-MAP-acid to produce (R)-DMPM, was applied. After a systematic optimization of dual-enzyme catalysis, the highest optical purity of (R)-DMPM ever reported with an e.e.p of 99.1% and an E value of 900 was obtained under the 49.2% conversion of (R,S)-DMPM and 96.2% of esterification yield conditions. The results overcome the limitations of racemization and provides a green, high-yield route for the industrial production of (R)-DMPM.
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Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 3
·122882
·
IF 7.5
Lingmei Yang,An Wei,Ru kuan Liu,Guo ling Zhang,Bing Han,Baining Lin,Lianhua Li
Non-noble metal NiCoAl-R catalysts with tunable Ni/Co molar ratios were rationally designed and synthesized for the liquid-phase selective hydrogenation of benzaldehyde to benzyl alcohol. A series of Ni x Co 1-x Al-R (x = 0.3, 0.5, 0.7) catalysts were successfully prepared, featuring a metal–metal oxide synergistic structure constructed via a hydrothermal–calcination–reduction method. The characterization revealed that the optimized Ni 0.5 Co 0.5 Al-R catalyst possesses an ideal "metal–metal oxide synergistic interface": the highest content of Ni 0 ensures superior intrinsic hydrogenation rates, while the spinel phase Co 3 O 4 effectively transfers electrons and anchors the active Ni 0 sites to prevent structural degradation. The well-defined mesoporous channels significantly enhance mass transfer and product diffusion, contributing to near-complete conversion of benzaldehyde (99.4%), a benzyl alcohol yield of 94.3%, and a low apparent activation energy of 73.74 kJ·mol⁻¹ . Furthermore, the catalyst demonstrated excellent recycling stability, maintaining a benzyl alcohol yield of 87.8% after reusing for five cycle. Compared with noble-metal-based counterparts, the developed NiCoAl-R catalytic system integrates high activity, excellent selectivity, robust structural stability, and distinct cost advantages, presenting a promising non-noble-metal paradigm for the selective hydrogenation of benzaldehyde with strong potential for industrial application.
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BIORESOURCE TECHNOLOGY
·
2026
·
IF 8.2
Guangyao Yang,Bingjie Liu,Shiyuan Xie,Yongqing Xu,Jingbo Jia,Hui Zhou,Dongwu Chang,Changfu You,Haiming Wang,Junfu Lyu
Biomass chemical looping gasification (BCLG) demonstrates great potential to help address global environmental issues and green energy demands. Yet it remains a challenge to develop novel oxygen carriers (OCs) in BCLG to break the trade-off between the biomass conversion and syngas selectivity with high syngas yield. In this study, Sr–Fe OCs labelled as S3F2, S4F2, and S5F2, containing primarily of Ruddlesden–Popper (R-P) layered perovskite structured Sr 3 Fe 2 O 7-x , were synthesized. Sr 3 Fe 2 O 7-x thermodynamically favors the selective formation of CO over CO 2 , conferring its inherently high CO selectivity. Both the interstitial oxygen and lattice oxygen were found to contribute to the gasification process, which presented enhanced activity and oxygen uncoupling characteristic. The excessive Sr incorporation in S4F2 and S5F2 further increased the oxygen vacancies of Sr 3 Fe 2 O 7-x , and caused a much higher oxygen mobility and oxygen release capacity (S5F2 > S4F2 > S3F2). Additional Sr in S5F2 formed Sr(OH) 2 ·H 2 O on Sr 3 Fe 2 O 7-x surface, which acted as additional oxygen source for gasification and also suppressed the overoxidation of syngas product on the surface. These combined features enabled the most favorable performance of S5F2 with a carbon conversion of 91%, CO selectivity of 94%, and syngas yield of 1208 mL/g at 900 °C, much higher than the Fe 2 O 3 benchmark (77.8%, 59.8%, and 557.9 mL/g, respectively).
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JOURNAL OF MEDICINAL CHEMISTRY
·
2026
·
IF 7.3
Haoran Li,Shuli Xia,Pengqi Zhang,Mengfei Li,Ling Lv,Xuetao Zhang,Xin Li,Zhiqing Liu,Chang-Yun Wang,Pingyuan Wang
G protein-coupled receptor 52 (GPR52) has been identified as a promising therapeutic target for the treatment of schizophrenia, psychiatric disorders, and other human neurological diseases. A series of novel 2,3-disubstituted pyrazine derivative GPR52 agonists have been designed, synthesized, and biologically evaluated. Through the exploration of the structure–activity relationship, several potent GPR52 agonists (14a, 14h, 14l, 20c, and 20i) were identified, with EC50 values in the nanomolar range (26–70 nM). Further studies on 14h indicate that it has excellent pharmacokinetic properties in mice and rats, as well as brain permeability (brain/plasma ratio = 1.6 and 3.1, respectively). In vivo, compound 14h (R-185) significantly inhibits MK-801-induced hyperlocomotor behaviors in zebrafish larvae and mice. Overall, our research results have identified an effective, orally bioavailable, and brain-permeable GPR52 agonist (14h), which is a promising candidate for the development of antischizophrenia drugs.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Ye Zhu,Qiong Hu,Wei Wei,Chenglin Yi,Xiaoya Liu
In this study a type of colloidal particles with a cross-linked poly(divinylbenzene) (poly(DVB)) core and a poly(acrylic acid- r -styrene) (PAS) shell were directly prepared by reversible addition-fragmentation chain transfer (RAFT)-mediated cross-linking copolymerization. The particle size, morphology, zeta potential and pH responsibility were studied. The emulsification study showed that PAS-Poly(DVB) colloidal particles were effective particulate emulsifiers when homogenized with various oils including toluene, white oil, isooctyl palmitate, dicaprylyl carbonate, silicone oil, and propylheptyl caprylate. Additionally, the emulsification performance of PAS-Poly(DVB) colloidal particles at different pH values were investigated. Gelled white oil- in -water high internal phase emulsions (HIPEs) were formed at a high oil volume fraction of 80% when the colloidal particles were flocculated at low pH value. The addition of base can trigger the demulsification of the HIPEs, exhibiting a pH-responsive behavior. The effects of oil phase volume fraction on emulsion rheological properties were investigated. Both the emulsion viscosity and storage modulus (G′) progressively increased with the increasing of oil phase volume fraction. These results suggest that our work provides a convenient and feasible way to prepare effective particulate emulsifiers via the direct chemical reaction, and the PAS-Poly(DVB) colloidal particles have promising potential application in the oil industry and preparation and exploitation of smart materials.
研究领域:
材料科学
·
化学工程
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Brazilian Journal of Pharmaceutical Sciences
·
2023
·
IF 1.3
Mei Xuejiao,Lu Dingqiang,Yan Xiangping
L-Malic acid is the Active Pharmaceutical Ingredient of the latest generation of compound electrolyte injection (STEROFUNDIN ISO, Germany) and plays a very important role in the rescue of critically ill patients. The optical purity of L-malic acid is a Critical Quality Attributes. A new reversed-phase high performance liquid chromatography (RP-HPLC) method for pre-column derivatization of D-malic acid enantiomer impurity in L-malic acid bulk drug was established. The derivatization reaction was carried out using (R)-1-(1-naphthyl)ethylamine ((R)-NEA) as a chiral derivatization reagent. The Kromasil C18 column was used with a detection wavelength of 225 nm, a flow rate of 1.0 mL·min-1, and a column temperature of 30 °C. The mobile phase was acetonitrile-0.01 mol·L-1 potassium dihydrogen phosphate solution (containing 20 mmol·L-1 sodium heptanesulfonate, adjusted to pH 2.80 with phosphoric acid) (at a ratio of 45:55) and the resolution of D-malic acid and L-malic acid derivatization products reached 1.7. The proposed method possesses the advantages of simple operation, mild conditions, stable derivatization products and low cost. Also it gave better separation and was more accurate than previous methods.
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FISH & SHELLFISH IMMUNOLOGY
·
2023
·
IF 4.7
Lili Yun,Meiru Kang,Yihao Shen,Junchang Feng,Guokun Yang,Jianxin Zhang,Xiaolin Meng,Xulu Chang
This study aimed to evaluate the effects of dietary supplementation with Bacillus velezensis R-71003 combined with sodium gluconate on antioxidant capacity, immune response and resistance against Aeromonas hydrophila in common carp . In addition, the biocontrol potential of the secondary metabolites of B. velezensis R-71003 was also evaluated to analyze the possible mechanism of B. velezensis R-71003 against A. hydrophila . The results indicated that the antibacterial crude extract of B. velezensis R-71003 can destroy the cell wall of A. hydrophila . Moreover, the results showed that dietary B. velezensis R-71003 could promote antioxidant capacity, which significantly increased the activities of CAT and SOD and decreased the content of MDA. Additionally, B. velezensis R-71003 supplementation significantly enhanced the immunity of common carp, as measured by the mRNA expression levels of cytokine-related genes ( TNF-α , TGF-β , IL-1β and IL-10 ). In addition, dietary B. velezensis R-71003 exhibited an upregulation of IL-10 and a downregulation of IL-1β, coupled with higher survival rates when challenged with A. hydrophila compared to the positive group. Furthermore, compared to prechallenge, the mRNA expression levels of TLR-4 , MyD88 , IRAK1 , TRAF6 , TRIF and NF-κB in the head kidney of common carp were significantly increased after challenge. The fish fed the B. velezensis R-71003 diet showed lower expression of TLR-4 , MyD88 , IRAK1 , TRAF6 , TRIF and NF-κB after the challenge than those fed the control diet. Thus, this study revealed that B. velezensis R-71003 can improve the resistance of common carp to pathogenic bacteria by destroying bacterial cell walls and improving fish immunity by activating the TLR4 signaling pathway . Importantly, this study indicated that sodium gluconate has a positive effect on B. velezensis R-71003 in enhancing the anti-infection ability of common carp. The results of this study will lay the foundation for the application of B. velezensis R-71003 in combination with sodium gluconate as an alternative to antibiotics in aquaculture.
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