MOLECULES
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2013
·Vol. 18
·期 4
·4158-4169
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IF 2.428
Luhui Ren,Xue Du,Mengnan Hu,Chaoqun Yan,Taigang Liang,Qingshan Li
An asymmetric synthesis of a series of novel 4-methyl-(3'S,4'S)-cis-khellactone derivatives3a–ois reported for the first time. Their structures were confirmed by1H-NMR,13C-NMR and MS. Their cytotoxic activity was evaluated by the MTT assay against three selected human cancer cell lines: HEPG-2 (human liver carcinoma), SGC-7901 (human gastric carcinoma), LS174T (human colon carcinoma). Some compounds showed high inhibitory activity against these human cancer cell lines. Among them, compound3aexhibited strong cytotoxicity, with IC50values ranging from 8.51 to 29.65 μM. The results showed that 4-methyl-cis-khellactone derivatives withS,Sconfiguration could be a potential antitumor agents.Keywords:4-methyl-(3'S,4'S)-cis-khellactone derivatives;asymmetric synthesis;antitumor activity
研究领域:
药物化学
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肿瘤学
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有机合成化学
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DOI
PubMed
高影响因子
Catalysis Science & Technology
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2024
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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.
研究领域:
生物化学
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生物技术
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酶工程
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有机化学
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蛋白质工程
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2025
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IF 2.5
Sleshi Fentie Tadesse,Worku Lakew Kebede,Dong-Hau Kuo
Visible-light-driven photocatalysis is an efficient and environmentally benign approach to mitigate organic pollutants from waste effluents. A facile one-step precipitation method was used to synthesize Fe–Mo3(O,S)4−x/La4Mo2O11 (FeLaMoOS) nanocomposites. The as-prepared materials were characterized by XRD, SEM, HR-TEM, XPS, PL, EIS, photocurrent, and UV-visible spectroscopy. The type I heterojunction formed between Fe–Mo3(O,S)4−x and La4Mo2O11 exhibited a maximum light absorption response in the visible spectrum. The FeLaMoOS composite (13% Fe and 20% La) demonstrated the highest degradation efficiency, degrading 97.5% MO and 99.2% RhB in 90 min. The removal efficiency of MB was 99.6% after 45 min of magnetic stirring in the dark. The enhanced catalytic efficiency can be attributed to the effective charge separation of photoinduced e−–h+ pairs due to doping and heterojunction formation. Superoxide radicals (O2˙−) played a dominant role, while hydroxyl radicals (˙OH) played only a minor role, in the photocatalytic degradation process. Possible photocatalytic degradation mechanisms of organic dye molecules were proposed, based on the active radical species involved and the band potentials of the photocatalysts. This study can be used to establish a simple and efficient strategy for designing reusable composite photocatalysts for the degradation of organic dyes.
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
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IF 9.4
Wenxue Zhao,Aihua Yan,Zigao Su,Fei Huang,Jixu Zhang,Ye Gao,Huaqi Yuan
Enabling highly-efficient multiplex-optimization photocatalysts is critical to overcome the bottlenecks of hydrogen evolution reaction efficiency and photostability. Herein, novel CoS/S v -ZnIn 2 S 4 /MoS 2 composites are successfully synthesized through an in situ technique. Taking advantage of the synergistic effect of sulfur vacancy, Schottky-type MoS 2 /S v -ZnIn 2 S 4 junction and Ohmic-type CoS/S v -ZnIn 2 S 4 junction, the light absorption, electron/hole separation efficiency, charge transfer rate and hydrogen reduction reaction dynamic can be significantly enhanced. As a result, an impressive photocatalytic hydrogen evolution rate of 18.43 mmol g −1 h −1 is achieved under the visible-light irradiation. Furthermore, apparent quantum efficiencies of 72.14 % and 9.91 % are also achieved under 350 and 420 nm monochromatic light irradiation. This work presents an in situ perspective to design multiplex-optimization photocatalytic system for highly-efficient hydrogen production.
研究领域:
材料科学
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光化学
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能源材料
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产品关联
DOI
PubMed
高影响因子
Drug Design Development and Therapy
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2017
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IF 2.822
Jingrun Chen,Junjie Liu,Dongxiao Cui,Chaoqun Yan,Liqiang Meng,Liqian Sun,Shurong Ban,Rui Ge,Taigang Liang,Qingshan Li
This study deals with the design and synthesis of a series of novel 4-methoxy-substituted and 5-methyl-substituted (3′S,4′S)-(−)-cis-khellactones. The newly synthesized compounds were characterized by 1H nuclear magnetic resonance (NMR), 13C-NMR, mass spectrometry, and elemental analysis. All the derivatives were subjected to in vitro cytotoxicity screening against HEPG-2 (human liver carcinoma), SGC-7901 (human gastric carcinoma), and LS174T (human colon carcinoma), by using the MTT assay. The results revealed that several of the 4-methoxy-substituted compounds exhibited potent cytotoxicity. Among these, compound 12e showed the highest activity against cancer cells which 50% inhibitory concentration (IC50) values were in the range of 6.1–9.2 μM with low toxicity on normal human hepatocyte. Preliminary investigation of possible mechanisms of action of compound 12e against HEPG-2 cells indicated possible induction of apoptosis, as determined by morphological observations and Annexin V/propidium iodide (PI) double staining, in addition to apparent dissipation of mitochondrial membrane potential (MMP), as measured by 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1) staining in combination with the activation of caspase-9 and caspase-3 by Western blot analysis. Overall, the data suggest that compound 12e may be a promising potential anti-cancer agent that could act primarily by inducing apoptosis through the mitochondria-mediated intrinsic pathway in human hepatoma cells.
研究领域:
药理学
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肿瘤学
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药物化学
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Hairus Abdullah,Sethupathi Shanmugasundaram,Mohamed Tarek Ahmed,Hardy Shuwanto,S.K. Krishna,Dong-Hau Kuo
Carbon-free based fuels are a promising solution to overcome the world energy crisis and environmental pollution . Therefore, hydrogen fuel is a critical and sustainable energy source to replace the limited carbon-based fossil fuels, which can be generated using a simple photocatalysis method. Herein, we demonstrated that Ni- and Mg-doped ZnIn 2 (O,S) 4 (NMZI) photocatalysts prepared with a hydrothermal process performed an unprecedented HER rate without a noble-metal cocatalyst under visible-light illumination. The amounts of Ni and Mg dopants in NMZI were varied and the as-prepared NMZI were characterized with SEM, TEM, XRD, Raman, FTIR, XPS, EPR, DRS, PL , EIS, TPC , CV, and tested for photocatalytic HER . It was found that the Ni and Mg co-dopants induced substitutional surface defects of Zn In − , Ni In − , and Mg In − . As a result, the formation of oxygen vacancy ( V O 2 + ) compensated the induced defect charges, which are crucial in the HER mechanism. EDS, ICP, and XPS analyses suggest a non-stoichiometric Zn(Zn,Ni,Mg,In) 2 (O,S) 3.5 with Zn, Ni, and Mg occupying In sites in the structure. The NMZI catalyst could achieve a maximum HER rate of 9.4 mmol/g․h under visible-light illumination. It is believed that the HER performance improvement is due to the defect formation on NMZI catalyst that subsequently enhances the optical, electrochemical, and photocatalytic properties. The photocatalytic HER mechanism has been elucidated and discussed thoroughly in this work.
研究领域:
材料科学
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能源与环境科学
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DOI
高影响因子
GREEN CHEMISTRY
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2023
·Vol. 25
·期 18
·7126-7140
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IF 9.8
Jiao Chen,Jiali Cai,Feng Sha,Wenjun Sun,Xilei Lyu,Yonghui Chang,Fei Cao,Lili Zhao,Hongli Wu,Pingkai Ouyang
As a potential substitute for petroleum-based terephthalic acid (TPA) in the manufacture of polyesters, 2,5-furandicarboxylic acid has been obtained through several feasible routes. Herein, a new chemo-enzymatic strategy for generating furan-2,5-dicarboxylic acid (FDCA) precursors from sodium gluconate via bio-oxidation and dehydration is presented. By coupling the bio-oxidation of gluconate 5-dehydrogenase with carbonyl reductase PsCR for cofactor regeneration, 5-keto-D-gluconic acid (5KGA), a specific product of D-gluconic acid bio-oxidation and a stable intermediate, was obtained in 99% yield. The statin intermediate ethyl (S)-4-chloro-3-hydroxybutanoate was simultaneously generated as a co-product via cycling cascade catalysis. Subsequently, the yield of the FDCA precursor n-butyl-5-formyl-2-furancarboxylate (nBu-FFCA) generated via5KGA dehydration and esterification reached 77.9%. Key intermediate characterization and theoretical calculations revealed that the decarboxylation and dehydration of cyclic 5KGA to furfural was the main side-reaction that prevented a better yield of dehydrated 5KGA. This route demonstrates good sustainability and market competitiveness compared to the existing FDCA synthesis methods.
研究领域:
化学工程
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生物化学
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材料科学
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可持续化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）