Molecular Catalysis
·
2022
·
IF 5.089
Shiyu Wei,Guochao Xu,Jieyu Zhou,Ye Ni
Baeyer-Villiger monooxygenases are recognized as valuable tools for biooxidative synthesis of chiral sulfoxides. In this work, a novel HAPMO ortholog from Pseudomonas fluorescens (HAPMO Pf ) was identified by genome mining. Evolutionary relationship and sequence analysis revealed that HAPMO Pf belongs to the family of typical type I BVMOs. HAPMO Pf has a low K M value (0.025 mM) toward 4-hydroxyacetophenone, and a half-life of 24 h at 30 °C and pH 9.0. HAPMO Pf exhibited distinct activity toward aromatic ketones as well as various thioethers, such as methyl phenyl sulfide and bromo‑methyl phenyl sulfide. The highest activities of HAPMO Pf was 1.47 U·mg −1 toward 4-hydroxyacetophenone among tested ketone and thioether substrates. Furthermore, over 95% enantioselectivity was determined toward methyl phenyl sulfides with ortho, meta, and para -substituents (Cl, Br, CHO, NH 2 ). Therefore, HAPMO Pf is a promising biocatalyst for the synthesis of aromatic esters and chiral sulfoxides.
研究领域:
生物化学
·
生物催化
·
酶学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Zhenyu Zhao,Xuting Wang,Shifu Wang,Zuoyi Xiao,Shangru Zhai,Jiliang Ma,Xiaoli Dong,Haodong Sun,Qingda An
The development of g-C3N4-based photocatalysts with abundant active sites is of great significance for photocatalytic reactions. Herein, a smart and robust strategy was presented to fabricate three-dimensional (3D) g-C3N4 nanosheet-coated alginate-based hierarchical porous carbon (g-C3N4@HPC), including coating melamine on calcium alginate (CA) hydrogel beads, freeze-drying hydrogel beads as well as pyrolysis at high temperatures. The resulting photocatalyst possessed a significantly high surface area and a large amount of interconnected macropores compared with porous carbon without the melamine coating. The unique structural features could effectively inhibit the curling and agglomeration of g-C3N4 nanosheets, provide abundant photocatalytic active sites, and promote mass diffusion. Therefore, the g-C3N4@HPC composite exhibited remarkable photocatalytic activity and outstanding stability toward the photoreduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 under natural sunlight and simulated visible-light irradiation (λ > 420 nm) using a 300 W xenon lamp. Moreover, the mechanism toward the photocatalytic reaction was extensively studied by quenching experiments and electron spin resonance (ESR) experiments. The results showed that active hydrogen species were able to be achieved by following a dual-channel pathway in the NaBH4 system, which included photocatalytic reduction of H+ ions and photocatalytic oxidation of BH4– ions. This work not only opens up a new way to design efficient photocatalysts for various reactions but also provides a reference for an in-depth study of the photoreduction mechanism.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Pan Li,Chunchao Hou,Xuehua Zhang,Yong Chen,Tao He
The hybrid coupling between inorganic semiconductor and molecular catalyst can provide a promising approach for the construction of highly efficient and selective photocatalytic CO 2 reduction systems. This hybrid system can take full advantage of the strong light harvesting capability of semiconductor and high selectivity of molecular catalyst. The interaction linker bridging the semiconductor and molecular catalyst plays an important role in supplying efficient electron transfer channels. In this study, both CdS with and without ethylenediamine functionalization (i.e., CdS-EF and CdS) have been successfully synthesized and further respectively coupled with tetra(4-carboxyphenyl)porphyrin iron(III) chloride (FeTCPP) for CO 2 photoreduction. It is found that CdS-EF exhibits inferior photocatalytic activity to CdS, while CdS-EF/FeTCPP hybrid photocatalyst shows much higher activity than CdS/FeTCPP. This is because hydrogen bonding exists between the amino groups in CdS-EF and carboxyl groups in FeTCPP, which can act as electron transfer channels from CdS to FeTCPP in the obtained hybrid system.
研究领域:
材料科学
·
光催化
·
环境化学
·
无机化学
·
分子催化
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Ze Feng,Yujia Xie,Fang Hao,Pingle Liu,He'an Luo
A series of manganese metalloporphyrins were prepared and tested in cyclohexane oxidation. It has been found that the manganese 5,10,15,20-tetrakis(4-nitrophonyl) porphyrin (Mn-TNPP) presents better catalytic performance. The Mn-TNPP was then immobilized on different supports, and characterized by UV–vis, FT-IR, XRD, TG/DTG and ICP. Among these supported Mn-TNPP catalysts, Mn-TNPP/ZnO exhibits the best selectivity to KA oil and higher turnover number in cyclohexane oxidation. The influence of the reaction conditions and the recycle of the catalysts are discussed. Mn-TNPP/ZnO catalyst presents the average cyclohexane conversion of 7.17%, KA oil selectivity of 91.18%, and the average catalytic turnover number of 6.53 × 10 4 after six times of recycle under 150 °C and 1.0 MPa.
研究领域:
催化化学
·
有机合成
·
工业化学
·
材料化学
·
绿色化学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Li Jiang,Yiqian Yang,Lin Huang,Yan Zhou,Junwei An,Yuchun Zheng,Yiwei Chen,Yanhong Liu,Jianhui Huang,Ee Lui Ang,Suwen Zhao,Huimin Zhao,Rongzhen Liao,Yifeng Wei,Yan Zhang
The various isomers of hydroxyproline (HP) are widely distributed in nature, serving as key components of structural proteins, while their quaternized betaine derivatives function as osmoprotectants in many organisms. Aerobic bacteria degrade HPs through a variety of well-studied mechanisms. Recent studies show that certain anaerobic bacteria degrade HPs through distinct mechanisms, involving the O2-sensitive glycyl radical enzymes (GREs) t4L-HP dehydratase (HypD) and t4D-HP C–N lyase (HplG). Here, we report the discovery of two more GREs, N-methyl c4L-HP dehydratase (HpyG) and N-methyl c4D-HP dehydratase (HpzG), which catalyze radical-mediated dehydration of the two N-methyl-c4HP enantiomers, while also displaying significant activities toward their unmethylated substrates. Both GREs are associated with homologues of pyrroline-5-carboxylate reductase, which catalyze reduction of their products N-methyl-pyrroline-5-carboxylate to form N-methyl-proline. Crystal structures of HpyG and HpzG in complex with their substrates revealed active site architectures distinct from that of HypD and provided insights into the mechanism of enantioselective radical-mediated dehydration. Our research further expands the repertoire of diverse chemical mechanisms involved in the bacterial metabolism of highly prevalent HP isomers and derivatives in the anaerobic biosphere.
研究领域:
生物化学
·
微生物学
·
酶学
✓ 已验证
DOI
高影响因子
SCIENTIA HORTICULTURAE
·
2024
·
IF 3.9
Qiong Wu,Xiaoya Tao,Chunxiao Cui,Yanan He,Dongdong Zhang,Yurong Zhang,Li Li
Phytohormones are vital for tomato ripening, and abscisic acid (ABA) is speculated to induce ethylene biosynthesis at the initiate of tomato fruit ripening; however, its interaction sites remain unclear. In the present study, Constans-like 4 (SlCOL4), a CO/COL transcription factor, was cloned from tomato fruit. Amino acid sequence and subcellular location analysis proved that SlCOL4 was a typical transcription factor of the COL family. Gene expression analysis showed SlCOL4 expressed in different tissues of tomato plants and its transcription abundance declined at the onset of fruit ripening, coincidentally it was found to be down-regulated in ABA-treated tomato fruit and responded to exogenous ABA within 6 h after treatment. Meanwhile, yeast one-hybrid and dual-luciferase analysis showed that the ABA response factor SlAREB1 inhibited the transcription of SlCOL4 , indicating it was directly regulated by ABA at the mature green stage of tomato fruit . In addition, the pericarp color turned red faster than that of control fruit, and the key ethylene biosynthesis genes, ACS2, ACS4, and ACO1 , were up-regulated in SlCOL4 silenced tomato fruit, suggesting that SlCOL4 may be a negative regulator of ripening. Furthermore, several genes associated with the ethylene signaling pathway were identified downstream of SlCOL4 by chromatin immunoprecipitation sequencing (ChIP-Seq) analysis. Overall, the transcription factor SlCOL4 may interact with ABA and ethylene signals and negatively regulate tomato fruit ripening. The results in this study provide new insights for elucidating the molecular mechanism of ABA-ethylene interaction in regulating tomato fruit ripening, and provide references for further research on the role of COLs transcription factors in tomato fruit ripening as well.
研究领域:
植物生理学
·
分子生物学
·
园艺学
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2023
·
IF 5.3
Yue Hua,Jingsen Zhang,Tengda Zhang,Aimin Zhu,Guangqing Xia,Xiuling Zhang,Lanbo Di
Catalytic removal of 4-nitrophenol (4-NP) in wastewater remains a significant challenge due to the poor activity and stability of the catalysts. Herein, low-cost graphite oxide (GO) supported Pd and Ni NPs (PdNi/GO) with enhanced catalytic activity and stability for 4-NP reduction were synthesized by a plasma method in the aqueous solution of Pd(NO 3 ) 2 , Ni(NO 3 ) 2 , and GO. The normalized rate constant k nor over the PdNi/GO with Pd/Ni= 1.8:0.2 for 4-NP reduction was as high as 5480 min −1 ·g −1 ·L, which was comparable with that of Pd/GO, and it was about 50.7 times higher than that of Pd/rGO-H prepared by traditional thermal reduction method. Importantly, after six reaction cycles, it only decreased to 74.8% of the initial value, which was much higher than that of the Pd/GO catalyst (59.8%). The characterization results indicated that plasma synthesized Pd/GO catalyst can keep the oxygen-containing groups (OCGs) on the GO surface , generate abundant defects, and facilitate the adsorption of the 4-NP. Interestingly, the addition of Ni could keep these merits, and the formed PdNi alloyed structure may facilitate the electron transfer between PdNi NPs and GO, contribute to the strong adsorption of 4-NP and the rapid generation of active hydrogen. Consequently, the PdNi/GO catalyst exhibited outstanding catalytic activity and stability for 4-NP reduction. This work provided a fast, facile, environmentally friendly, and easy to scale up plasma method for synthesizing high performance Pd-based catalysts.
研究领域:
环境催化
·
纳米材料
·
物理化学
·
水处理
·
能源与环境科学
✓ 已验证
DOI
高影响因子
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2018
·Vol. 39
·期 5
·611-617
·
IF 0.522
Qi Sun,Jianmei Li,Tao Le,Lei Zhang
Herein, a facile and enzyme-free CP sensor was fabricated by in situ electrochemical reduction strategy on the surface of glassy carbon electrode (GCE). Reduced graphene oxide (RGO) was chose as supporting materials for the distribution of platinum nanoparticles (Pt NPs) to obtain improved catalytic properties. The applicability and suitability of the obtained RGO-Pt/GCE for 4-CP detection were also evaluated. The results indicated that the RGO-Pt NPs modified electrode displayed much better catalysis and higher sensitivity for 4-CP oxidation. Under optimum conditions, the oxidation peak current was proportional to 4-CP concentration in the range from 0.1 to 500 μM with a detection limit of 51 nM. Meanwhile, it is demonstrated that the prepared sensor is also characterized by excellent feasibility, satisfactory reproducibility, good stability and high specificity. The results suggested that RGO-Pt/GCE could be a facile, cost-effective, and rapid tool for the prospect on-line evaluation of 4-CP in drinking water samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
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.
研究领域:
生物化学
·
合成生物学
·
代谢工程
✓ 已验证
DOI
PubMed
高影响因子
ZEITSCHRIFT FUR KRISTALLOGRAPHIE-NEW CRYSTAL STRUCTURES
·
2023
·Vol. 238
·期 6
·1069-1070
·
IF 0.3
Yan-Qing Wang,Wen-Qing Yan,Li-Xue Nie,Ping-Ping Luan,Chao-Qun Li
C 20 H 22 Cu 3 N 8 O 10 , monoclinic, C 2/ c (no. 15), a = 12.0766(11) Å, b = 16.2778(14) Å, c = 14.7605(13) Å, β = 97.8580(10) ∘ , V = 2874.4(4) Å 3 , Z = 4, R
gt ( F ) = 0.0420, wR
ref ( F
2 ) = 0.0988, T = 298.15 K.
研究领域:
无机化学
·
晶体学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 28
·16955-16961
·
IF 3.361
Zeng-Feng Wei,Li-Jie Ni,Heng Quan,Jiang Duan
4-Substituted catechols with different CC bonds as urushiol analogues were synthesized through the a three-step route including reductive amination reaction of 3,4-dihydroxybenzaldehyde with N-Boc-piperazine, Boc deprotection, and amidation with various fatty acids. Electrochemical polymerization of these analogues on a copper surface afforded robust coatings with desirable adhesive force, hydrophobicity and thermal stability. Cyclic voltammetry and infrared spectroscopic characterizations revealed that the coating formation of urushiol analogues resulted from the electrooxidation-induced radical coupling of phenoxyl radicals with a phenyl ring and the side chain CC bond. The coating of the urushiol analogue bearing only one side chain CC bond exhibited the best performance in copper corrosion inhibition, with an inhibition efficiency of 99.99% and long-term effect (99.9% after 4 weeks of immersion in 3.5 wt% NaCl). The desired performance of these urushiol analogues suggests that they could be of practical applications as an alternative to the resource-limited natural urushiol.
研究领域:
有机化学
·
材料科学
·
腐蚀与防护
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2020
·Vol. 167
·期 13
·136513
·
IF 3.721
Nannan Dou,Jianying Qu
Herein, a hybrid nanomaterial of copper-nickel bimetal and reduced graphene (rGO) was simply and quickly synthesized by hydrothermal method, which was characterized by transmission electron microscope, field emission scanning electron microscopy, fourier transform infrared spectroscopy, electrochemical impedance and X-ray diffractometry. A new type of electrochemical sensor was constructed by fixing this hybrid on the glassy carbon electrode (GCE). Square wave voltammetry and cyclic voltammetry indicate that this Cu-Ni/rGO/GCE sensor has highly sensitive electrocatalytic activities to 4-aminophenol (4-AP) and acetaminophen (AC). The linear detection ranges were 0.10∼50.00 μM for AC and 0.10∼30.00 μM for 4-AP, with the detection limits of 2.13 nM for AC and 2.19 nM for 4-AP, respectively. The Cu-Ni/rGO/GCE was successfully used for the determination of 4-AP and AC simultaneously of paracetamol tablets, and satisfactory results were obtained.
研究领域:
材料科学
·
分析化学
·
生物医学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）