ACS Sustainable Chemistry & Engineering
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2016
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IF 5.267
Yuling Zhao,Jikuan Qiu,Li Tian,Zhiyong Li,Maohong Fan,Jianji Wang
Carbon dioxide (CO2) is an abundant and renewable feedstock for the production of high-value chemicals. Herein, CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were employed as an efficient catalyst system to synthesize 2-oxazolidinones through the coupling reaction of CO2 and propargylic amines. It was found that this cost-competitive catalyst system could efficiently catalyze the reaction within only 4 h at atmospheric pressure CO2, and a wide range of substrates were suitable for this reaction. Various target products were obtained in excellent yields. Furthermore, the catalytic mechanism of the CuI/DBU system was investigated by using density functional theory. It was shown that copper(I) and DBU played synergistic roles in activating both the C≡C triple bond and the amino group of propargylic amines in the reaction.
研究领域:
有机化学
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催化化学
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产品关联
DOI
高影响因子
BIOORGANIC CHEMISTRY
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2025
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IF 4.7
Ji Ding,Jinsong Song,Shengbo Huang,Chuanhua Zhou,Feng Xue
Enantiomerically pure 2-oxazolidinones are widely used as chiral auxiliaries in organic synthesis, but there is an unmet need for more effective methods to access these compounds. Here we report the identification and semi-rational engineering of the halohydrin dehalogenase Sl HHDH from Sneathiella limimaris for the highly enantioselective ring-opening of phenyl glycidyl ether (PGE) with cyanate to yield ( S )-5-phenoxymethyl-2-oxazolidinone. After single and combinatorial mutagenesis, the best enantioselective triple mutant, F15W/A137T/N179L achieved an enantioselectivity of 97 %, with an E valu e of 154. In addition, it could accept a wider range of PGEs to generate corresponding ( S )-5-phenoxymethyl-2-oxazolidinones, whereby the product ee values increased from less than 5 % in wild-type Sl HHDH to between 81 and 96 % in the triple mutant. Structural analysis of Sl HHDH and mutant F15W/A137T/N179L in complex with the substrate PGE showed that changes of the substrate-binding pocket in the mutant position R- PGE farther from the catalytic residues, which may explain the enhanced enantioselectivity. This mutant has great potential as a biocatalyst for the first synthesis of chiral ( S )-5-phenoxymethyl-2-oxazolidinones.
研究领域:
生物化学
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合成生物学
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酶工程
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DOI
PubMed
高影响因子
Catalysis Science & Technology
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2021
·Vol. 11
·期 21
·7072-7082
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IF 6.119
Xiao-Chao Chen,Kai-Chun Zhao,Yin-Qing Yao,Yong Lu,Ye Liu
The development of an efficient methodology to transform CO2 into valuable chemicals has attracted increasing attention concerning the challenging issues of CO2-utilization. Herein, an efficient approach for the preparation of oxazolidinones from CO2, primary (aliphatic/aromatic) amines and 1,2-dichloroethane (or its derivatives) catalyzed by DBU organo-superbase was achieved with yields of 47–97% under mild conditions (80–100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU–amine–CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable product oxazolidinones upon attack of 1,2-dichloroethane (or its derivatives), along with the regeneration of the DBU catalyst. Alternatively, the decomposition of the DBU–aryl amine–CO2 adduct (like IS-B-1) with relatively poor stability also could result in the competitive substitution reaction of 1,2-dichloroethane (or its derivatives) with the aryl amine. This work provides insights into synergetic CO2-activation by the DBU-catalyst and a nucleophilic amine-substrate via the formation of robust carbamate salt intermediates responsible for the final production of oxazolidinones.
研究领域:
有机化学
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环境化学
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DOI
高影响因子
Journal of Inflammation Research
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2022
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IF 4.631
Fan Ye,Yucui Jiang,Jian Zhang,Yingxin Zong,Mei Yu,Cuihua Chen,Chan Zhu,Yan Yang,Keke Jia,Gongxi Chen,Zongxiang Tang
Background Senecio scandens Buch.-Ham (S. scandens) belongs to the Compositae family. As a Traditional Chinese medicine, S. scandens has been used in China to treat conjunctivitis, mastitis and vaginitis, it also has the function of antibacterial and relieving itching.Methods Water extract of S. scandens (WSS) was prepared and its quality was controlled by HPLC. The antipruritic effects of WSS were evaluated by itch behavioral experiments. The oxazolone and compound 48/80 were induced to mice scratch behavior, scratch was recorded 30 min after sensitization. The relationship between the antipruritic mechanism and MrgprB2 on mast cell was studied by using mast cell-deficient Kit (W-sh) “Sash” mice and MrgprB2−/− mice. The mast cells were observed by toluidine blue staining. In vitro, the effects of WSS on MrgprB2 were studied by calcium imaging; The whole-cell patch clamp method recorded the MrgprB2 mediate voltage-dependent currents in mast cells.Results The content of rutin (0.012%) and hyperin (0.014%) in the WSS were determined. WSS could ameliorate the pruritus induced by Oxazolone (inhibition was 41.19%, p = 0.004) and compound 48/80 (inhibition was 50.29%, p = 0.001). Meanwhile, WSS could reduce the number of mast cells in mice skin tissue with allergic contact dermatitis (ACD) (p = 0.002) or compound 48/80 (p = 0.013). In addition, WSS could inhibit the calcium influx (1 mg/mL: p = 0.001, 3 mg/mL: p < 0.0001) and the voltage-dependent currents induced by activation of MrgprB2 on mast cell. WSS also attenuated the calcium influx induced by compound 48/80 in HEK293 cells overexpressing MrgprB2/X2.Conclusion These results showed that WSS could ameliorate pruritus by inhibiting MrgprB2 receptor on mast cells.
研究领域:
药理学
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免疫学
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中药学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
TALANTA
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2017
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IF 4.162
Ke Mao,Haiqin Du,Longchao Bai,Yalin Zhang,Haikun Zhu,Yanmei Wang
In this work, a one-step coating procedure by a simple annealing protocol of poly (2-methyl-2-oxazoline)-random-glycidyl methacrylate (PMOXA-r-GMA) copolymer was used to yield covalent and cross-linked PMOXA-based antifouling coating on a fused-silica capillary inner surface, which was used to determine the bovine lactoferrin (Lf) in infant formula by capillary electrophoresis with ultraviolet (CE-UV) detection. The X-ray photoelectron spectroscopy (XPS) confirmed that PMOXA-r-GMA could be bonded onto fused-silica capillary inner wall and stable electroosmotic flow (EOF) was obtained in the PMOXA-r-GMA coated capillary at pH 2.2–9.0. The separation of a mixture of four basic proteins indicated that the PMOXA-r-GMA coated capillary exhibited excellent separation efficiency for the basic proteins. Therefore, the PMOXA-r-GMA coated capillary was used to determine the quantity of Lf in infant formula. Under the optimal conditions, the peak area (A) and the concentration of Lf showed a good linear relationship within the range of 10–500 μg/mL with a linear correlation coefficient of 0.9995. The limit of detection (LOD) and limit of quantitation (LOQ) for Lf were 5.0 μg/mL and 16.7 μg/mL, respectively. The recoveries at spiked concentrations of 0.20 and 0.40 mg/mL Lf in infant formula were 97.1±5.5% – 97.8±5.1%. The determined values of Lf in infant formula samples with Lf were consistent with the nominal values, indicating that our CE method could be successfully applied to the quantitative analysis of Lf in commercial infant formula.
研究领域:
分析化学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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