OPTICAL MATERIALS
·
2024
·
IF 3.8
Worku Lakew Kebede,Kuo Dong-Hau,Chen Xiaoyun
Metal oxide semiconductor photocatalysts have received remarkable consideration as a promising technology for environmental remediation and energy conversion. Oxysulfide semiconductors have narrow band gaps which are appropriate for photocatalytic removal of toxic organic pollutants under visible light illumination. For the elimination purpose of these pollutants, Mo(O,S) 2 , Mn(O,S) 2 , and Mn–Mo(O,S) 2 oxysulfide catalysts containing various Mn contents were synthesized at low temperatures via a simple method. The structural, morphological, electrochemical, compositional, and optical properties of the as-synthesized catalysts were exhaustively characterized. The photocatalytic degradation activity of the bares Mo(O,S) 2 , Mn(O,S) 2 , and other Mn–Mo(O,S) 2 compositions were evaluated over different types of organic pollutants under visible light illumination. The addition of Mn in Mo(O,S) 2 structure improved the photodegradation activity, and Mn–Mo(O,S) 2 -30 was found to be the best composition with superior photodegradation performance towards the four cationic, anionic, and neutral dyes. The degradation efficiency of 10 ppm of MB, and MO dyes reach 99.7 % and 98.6 %, within 30 and 120 min, respectively. Mn–Mo(O,S) 2 -30 catalyst also shows a good photodegradation performance on Rh B and NR organic pollutants. According to the recycling test, the catalyst exhibited excellent performance. The photodegradation follows pseudo-first order kinetics with a rate constant of 0.097 and 0.036 min −1 for MB and MO dyes, respectively. The trapping experiment showed that superoxide anion radicals (O 2 •- ) and holes (h + ) are the responsible active species for the degradation on MO and MB, respectively. The novelty of using Mn–Mo(O,S) 2 -30 for various dyes degradation lies in its remarkable catalytic properties.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2025
·Vol. 41
·期 4
·1-15
·
IF 4.2
Zhao Jing-yi,Gao Fan,Wu Mengru,Li Yang,Chen Yong,Xiao Zijun
Enantiopure ( S )-2-methylbutanoic acid [( S )-2-MBA] is a high-value chiral compound with applications in fragrances, pharmaceuticals, and agrochemicals. However, conventional chemical synthesis lacks stereoselectivity, while existing biosynthetic methods suffer from low yield and purity. Here, we report a novel microbial process using Bacillus spizizenii ATCC 6633 for efficient ( S )-2-MBA production via L-isoleucine catabolism. Through targeted screening of rhizospheric soil isolates and Bacillaceae strains, ATCC 6633 demonstrated superior performance, producing 3.67 g/L ( S )-2-MBA with 99.32% enantiomeric excess ( ee ) under optimized conditions (45 °C, 8% inoculation, 5 g/L glucose, and 8 g/L L-isoleucine). A 58.92% conversion efficiency was achieved, and a simplified purification process recovered 63.90% product with 97.32% purity. Mechanistic studies suggested glucose depletion triggered ( S )-2-MBA accumulation, aligning with starvation-induced secondary metabolism. This cost-effective, eco-friendly approach eliminates racemic separation steps and harsh reagents, positioning ATCC 6633 as a promising biocatalyst for sustainable ( S )-2-MBA production.
研究领域:
生物化学
·
微生物学
·
有机化学
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产品关联
DOI
PubMed
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2016
·Vol. 358
·期 18
·2923-2928
·
IF 6.453
Peiyuan Yao,Yunfeng Cui,Shanshan Yu,Yuncheng Du,Jinhui Feng,Qiaqing Wu,Dunming Zhu
An efficient multi-enzyme cascade reaction for the synthesis of ( R )- or ( S )-2-hydroxybutyric acid [( R )- or ( S )-2-HB] from l -threonine was developed by using recombinant Escherichia coli cells expressing separately or co-expressing l -threonine deaminase from Escherichia coli K-12 ( ilvA ), formate dehydrogenase (FDH) from Candida boidinii and l -lactate dehydrogenase ( l -LDH) from Oryctolagus cuniculus or d -lactate dehydrogenase ( d -LDH) from Staphylococcus epidermidis ATCC 12228. Up to 750 mM of l -threonine were completely transformed to ( R )- or ( S )-2-HB in optically pure form (>99% ee ) with high isolated yields. This one-pot multi-enzyme transformation provides a new practical method for the synthesis of these important optically pure compounds.
研究领域:
生物化学
·
合成生物学
·
代谢工程
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 45
·19868-19879
·
IF 3.288
Sleshi Fentie Tadesse,Dong-Hau Kuo,Worku Lakew Kebede,Lalisa Wakjira Duresa
Discharging of organic pollutants from industrial activities into the water bodies is a common worldwide problem, which can adversely affect human life and the environment. Recently, many efficient, eco-friendly, and cost-effective photocatalytic methods have been investigated for environmental remediation. In this study, a simple and facile precipitation method at low temperature was proposed for the synthesis of V-doped Mo(O,S)2 oxysulfide. The crystallinity, morphology, elemental composition, and optical and electrical properties of the as-synthesized materials were characterized by XRD, Raman spectroscopy, FT-IR spectroscopy, FE-SEM, TEM, XPS, PL, and EIS. The photocatalytic performance of both bare and V-doped Mo(O,S)2 was evaluated in the degradation of methylene blue (MB) dye. The holes (h+) and hydroxyl radicals (OH˙) were identified as the main oxidative species for MB degradation. V-Mo(O,S)2-10 synthesized with 10% vanadium precursor showed the highest photocatalytic efficiency for MB degradation under visible light irradiation with an apparent rate constant of 0.028 min−1, which was much greater than that of bare Mo(O,S)2 at 0.0098 min−1. Besides, V-Mo(O,S)2-10 had the lowest recombination rate of electron–hole pairs and charge transfer resistance to enhance the photocatalytic activity, as evidenced by PL and EIS analyses. Therefore, V-doped Mo(O,S)2 can be a potential candidate for photocatalytic degradation of organic dyes for environmental remediation.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Worku Lakew Kebede,Dong-Hau Kuo,Xiaoyun Chen
Environment and energy are presently some of the highest priority topics for mankind that need to be addressed. Organic pollutants are toxic and carcinogenic for human and aquatic life hence their presence in water even in low concentrations can cause serious health problems. Photodegradation of organic pollutants by utilizing oxide-based heterostructure photocatalysts is the promising approach to carry out remediation efficiently ascribed to the advanced optoelectronic and structural superiority of oxide photocatalysts. The Zn(O,S)/Mo(O,S) 2 composites were synthesized via a facile solvothermal method at low temperatures. Several methods were used to characterize the composite morphology, structure, electrical conductivity, chemical composition, and optical characteristics. The heterostructured Zn(O,S)/Mo(O,S) 2 oxysulfide was employed successfully in the photocatalytic degradation of organic pollutants. Among the as-prepared samples, the 30-ZnMoOS composite catalyst was found to have the highest photodegradation performance on various organic dye pollutants. The photocatalytic activity of the as-synthesized Zn(O,S)/Mo(O,S) 2 samples was assessed on the photodegradation of different kinds of organic dyes under visible light irradiation. The photocatalytic degradation efficiency of 30-ZnMoOS composite over 10 ppm neutral red (NR), methylene blue (MB), rhodamine B (Rh B), and methyl orange (MO) was found to be 99.6 %, 99.9 %, 99.5 %, and 98.8 % within 40, 45, 180, and 180 min, respectively, under visible light illumination. In the present photocatalytic system, the superoxide ( . O 2 - ) anions, hydroxyl ( . OH) radicals, and holes (h + ) are proposed to be the direct reactive species causing the photodegradation of organic dyes.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Worku Lakew Kebede,Dong-Hau Kuo,Fekadu Tadesse Bekena,Lalisa Wakjira Duresa
Environmentally toxic organic pollutants, namely methylene blue (MB), neutral red (NR), Rhodamine B (RhB), and methyl orange (MO) dyes contain highly toxic, carcinogenic, non-biodegradable, and colored pigments which cause harm for humans and aquatic organisms even at low concentrations. To detoxify these toxic organic pollutants from the wastewater, the bimetallic solid solution-typed In–Mo(O,S) 2 catalyst with various indium (In) contents were synthesized at low temperature through a simple precipitation method. The morphological, structural, chemical compositions, electrochemical and optical properties of the catalysts were thoroughly characterized. The photodegradation performance of the In–Mo(O,S) 2 catalysts over the cationic, anionic and neutral dyes were studied under visible light irradiation. It has been observed that the photocatalytic activity was enhanced as In was added to the Mo(O,S) 2 catalyst, and In–Mo(O,S) 2 -20 was found to be the best composition to completely degrade four organic dyes. The dye degradation had rate constant values of 9.5 × 10 −2 min −1 , 6.3 × 10 −2 min −1 , 4.4 × 10 −2 min −1 , and 15.7 × 10 −1 min −1 for MB (20 ppm), NR (20 ppm), RhB (10 ppm), and MO (10 ppm) dyes, respectively. The active species for degradation of MB is different from those for RhB and MO. Single phase In–Mo(O,S) 2 -20 capable to degrade four kinds of dyes at a fast rate is a good photocatalyst.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Fekadu Tadesse Bekena,Dong-Hau Kuo,Worku Lakew Kebede
Wastewater treatment becomes an important part to improve environmental quality and protect water resources. Thus, developing a new photocatalyst is a key solution for environmental issues. Herein, universal, highly efficient, and novel Bi 2 (O,S) 3 /Mo(O,S) 2 nanocomposite photocatalyst was fabricated by a facile method and the crystal structure, morphology, composition, and optical properties of the as-prepared catalysts were characterized in details. The photocatalytic performance of the catalysts was evaluated by the photodegradation of methyl orange (MO), rhodamine B (RhB), methylene blue (MB), and neutral red (NR), the results showed that 20% Bi-MoOS nanocomposite had excellent photodegradation activity towards all dyes. 96.0% of MO, 96.6% of RhB, 98.8% of MB and 91.3% of NR dyes were removed after 180 min, 40 min, 20 min, and 25 min visible light irradiation, respectively. The photodegradation of these dyes was further confirmed with HPLC. The excellent photocatalytic activity of the nanocomposites was due to the efficient separation and transport of photogenerated charge carriers induced by the fabricated binary heterostructures. The photodegradation fitted well the pseudo-first-order kinetics. The active species capture experiment study showed that, OH, O 2 − and h + all took parts in the degradation of dyes. The stability of the catalyst and reaction mechanism also explained in this work.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2022
·
IF 3.595
Feng Cheng,Wei-Bang Xie,Xiao-Fan Gao,Rong-Liang Chu,Shen-Yuan Xu,Ya-Jun Wang,Yu-Guo Zheng
( S )-2-chlorophenylglycine (( S )-CPG) is a key chiral intermediate for the synthesis of clopidogrel . Herein, a novel, efficient and environmentally friendly chemo-enzymatic route for the preparation of optically pure ( S )-CPG was developed. A straightforward chemical synthesis of the corresponding prochiral keto acid substrate (2-chlorophenyl)glyoxylic acid (CPGA) was developed with 91.7% yield, which was enantioselectively aminated by leucine dehydrogenase (LeuDH) to ( S )-CPG. Moreover, protein engineering of LeuDH was performed via directed evolution and semi-rational design. A beneficial variant Es LeuDH-F362L with enlarged substrate-binding pocket and increased hydrogen bond between K77 and substrate CPGA was constructed, which exhibited 2.1-fold enhanced specific activity but decreased thermal stability . Coupled with a glucose dehydrogenase from Bacillus megaterium ( Bm GDH) for NADH regeneration, Es LeuDH-F362L completely converted up to 0.5 M CPGA to ( S )-CPG in 8 h at 40 °C.
研究领域:
有机化学
·
生物化学
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生物催化
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药物化学
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DOI
PubMed
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2022
·
IF 3.858
Jianjiong Li,Shanshan Yu,Yingang Wang,Peiyuan Yao,Qiaqing Wu,Dunming Zhu
(S)-2-Aminobutane, d-alanine, and d-homoalanine are important intermediates for the production of various active pharmaceutical ingredients and food additives. The preparation of these small chiral amine or amino acids with high water solubility still demands searching for efficient methods. In this work, we identified an ω-transaminase (ω-TA) from Sinirhodobacter hungdaonensis (ShdTA) that catalyzed the kinetic resolution of racemic 2-aminobutane at a concentration of 800 mM using pyruvate as the amino acceptor, leading to the simultaneous isolation of enantiopure (S)-2-aminobutane and d-alanine in 46% and 90% yield, respectively. In addition, (S)-2-aminobutane (98% ee) and d-homoalanine (99% ee) were isolated in 45% and 93% yield, respectively, in the kinetic resolution of racemic 2-aminobutane at a concentration of 400 mM coupled with deamination of l-threonine by threonine deaminase. We thus developed a biocatalytic process for the practical synthesis of these valuable small chiral amine and d-amino acids.
研究领域:
生物催化
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有机化学
·
药物化学
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DOI
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2020
·
IF 3.503
Chun-Yue Weng,Dan-Na Wang,Shan-Yun Ban,Qiu-Yao Zhai,Xin-Yi Hu,Feng Cheng,Ya-Jun Wang,Yu-Guo Zheng
( S )-2-chlorophenylglycine methyl ester (( S )- 1 ) is a key chiral building block of clopidogrel, which is a widely administered antiaggregatory and antithrombotic drug. Herein, Protease 6SD was covalently immobilized on multi-walled carbon nanotubes (MWCNT), and the as-prepared immobilizate P-6SD@NH 2 -MWCNT was applied in the enantioselective resolution of ( R,S )- 1 to yield ( S )- 1 . In order to overcome the poor solubility of ( R,S )- 1 in aqueous solution, a novel triphasic reaction system constituting P-6SD@NH 2 -MWCNT, aqueous phase and methyl tert -butyl ether (MTBE) as the organic phase was constructed, which simultaneously improved the substrate solubility and the immobilizate recyclability. Under the optimized reaction conditions, P-6SD@NH 2 -MWCNT catalyzed 10 mM ( R,S )- 1 for 2 h, yielding optically pure ( S )- 1 (>99.0 % ee s ) with 70.74 % conversion of the ( R,S )- 1 . Moreover, P-6SD@NH 2 -MWCNT can be reused for 15 batches, displaying an exquisite recycling performance. It is for the first time that enantiomerically pure ( S )- 1 was successfully synthesized by protease-catalyzed one-step resolution.
研究领域:
生物化学
·
制药工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Linghui Kong,Bo Fan,Yu-Cai He
( S )-2-Chloro-1-(3,4-difluorophenyl)-ethanol [( S )-CFPL] is a key chiral intermediate in the manufacture of Ticagrelor. In this study, deep eutectic solvent (DES) was used as the co-solvent, and several reaction parameters were investigated and characterized. It was observed that supplementary of DES could promote the asymmetric reduction of 2‑chloro-1-(3,4-difluorophenyl) ethanone (CFPO) to ( S )-CFPL through the biological reduction by recombinant E. coli containing a NADH-dependent reductase CmCR. The high pKa value of carboxylic acid in DES and low viscosity of DES were beneficial to increase cell membrane permeability and enhancement of biocatalytic efficiency. By supplementary of DES ChCl:LA (7.5 vol%) into the bioreaction system, the efficient bioreduction reaction of 100 mM CFPO was achieved via the biocatalysis with whole-cell at 30 °C and pH 7.0, affording ( S )-CFPL in 95.9 % yield and optical purity > 99 %. The process was environmentally friendly with high biocatalytic productivity and had potential practicability in the mass production of ( S )-CFPL.
研究领域:
生物化学
·
合成生物学
·
绿色化学
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DOI
高影响因子
NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY
·
2019
·Vol. 393
·期 6
·967-978
·
IF 2.058
Rong Rong,Zhang Rui-zhen,Wang Xin,Dan Yu-han,Zhao Yun-li,Yu Zhi-guo
R -/ S -2-(2-hydroxypropanamido) benzoic acid ( R -/ S -HPABA), marine-derived anti-inflammatory antiplatelet drugs, were initially synthesised in our group. However, preliminary research showed that R -/ S -HPABA were eliminated rapidly because of extensive hydroxylation metabolism of phenyl ring in vivo. In order to reduce significant hydroxylation metabolism to improve pharmacological activity and bioavailability, trifluoromethyl group was incorporated into R -/ S -HPABA to synthesise R -/ S -2-(2-hydroxypropanamido)-5-trifluoromethyl benzoic acid ( R -/ S -HFBA), respectively. The purposes of this study were to report the synthesis of R -/ S -HFBA and compare the anti-inflammatory antiplatelet effect and pharmacokinetic properties of R -/ S -HFBA with those of R -/ S -HPABA. Carrageenan-induced rat paw edema assay was used for the evaluation of the anti-inflammatory activity. R -/ S -HFBA showed better results in inhibiting edema and were able to prolong the anti-inflammatory effect after carrageenan injection. The antiplatelet aggregation activity of R -/ S -HFBA and R -/ S -HPABA was studied on arachidonic acid-induced platelet aggregation of rabbit platelet-rich plasma. The aggregation inhibition rate of R- / S -HFBA was significantly ( p < 0.05) higher than that of R- / S -HPABA, respectively. Molecular docking study revealed that R -/ S -HFBA possess more potent binding affinity with COX-1/COX-2 than R -/ S -HPABA, respectively, and that the presence of trifluoromethyl group leads to increase in activity of R -/ S -HFBA. R -/ S -HFBA also afford more favorable pharmacokinetic properties than R- / S -HPABA, respectively, such as higher C max , larger AUC 0-∞ , and longer t 1/2 , which, as expected, are more metabolically stable.
研究领域:
药理学
·
药物化学
·
药物设计
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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）