SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Yuanchao Pei,Yaxin Zhang,Jie Ma,Yang Zhao,Zhiyong Li,Huiyong Wang,Jianji Wang,Ran Du
Development of porous adsorption materials tethered with functional groups was favorable to establish a more efficient, stable and broad-spectrum metal ions removal strategy from water. In this work, carboxyl functional poly(ionic liquid)s@MOF composites were prepared through in situ polymerization of ILs monomers inside MOF pores. Their thermophysical property, structure and morphology were characterized by different techniques. These PILs@MOF composites were proposed as universal and efficient adsorbents to remove selected rare earth metal ions (La 3+ , Sm 3+ , Nd 3+ ) and heavy metal ions (Pb 2+ , Cd 2+ ) from water medium. Effect of pH value and composite dosage on the adsorption efficiency were studied in detail. The optimized adsorption efficiency as high as 99.8 % could be found for the selected metal ions by PIL@MIL-101. In addition, the isotherms, kinetics and thermodynamic parameters of the adsorption process were also determined, and these results imply that the Langmuir model and pseudo-second-order model fitted well with the experimental data. Thermodynamic parameters revealed spontaneous and exothermic nature of the adsorption process. A plausible mechanism for the adsorption process was suggested by the electrostatic interaction and coordination between the carboxyl group and metal ions with the aid of FTIR and XPS measurements. Finally, recycling experiments were performed to demonstrate the recyclability and stability of PIL@MOF composites undergoes at least five adsorption–desorption runs. The current research presented a series of poly(ionic liquid)s@MOF composites as a universal adsorption platform that demonstrated great potential for removing metal ions with remarkable efficiency.
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2022
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IF 4.831
Wen Liu,Jinyao Li,Zicheng Wang,Yafei Tian,Guodong Ren,Xiaoyu Hou,Lixia Guo,Lihong Li,Chengwu Zhang,Zhifang Wu,Lili Yan,Sijin Li,Haipeng Diao
Sulfur dioxide (SO 2 ) is a key molecule in organisms that is involved in the regulation of different physiological procedures. Aberrant SO 2 causes a variety of diseases, such as cancer and neurodegeneration. Thus, sensitive and selective detection of SO 2 is of great importance. Based on the Förster resonance energy transfer (FRET) between green fluorescence carbon dots (GCDs) donor and amide-linked near-infrared fluorescence emissive organic small molecular dye (CDDBT) acceptor, one ratiometric fluorescent nano platform, Mito-GCDs-CDDBT for mitochondria SO 2 sensing was constructed. In this FRET sensing system, CDDBT served as the receptor for SO 2 , and the presence of SO 2 enhanced GCDs green fluorescence signal and quenched CDDBT near-infrared fluorescence signal due to the disruption of FRET. Mito-GCDs-CDDBT could sensitively detect SO 2 with a detection limit of as low as 0.701 μM. Meanwhile, Mito-GCDs-CDDBT achieved fluorescence imaging to measure the response of cellular exogenous and endogenous SO 2 with remarkable mitochondrial targeting. Moreover, Mito-GCDs-CDDBT also realized SO 2 sensing in vivo including zebrafish and mice. The as-prepared versatile nanoplatform displayed several advantages, such as mitochondria targeting, FRET-based sensitive detection, and sensing capabilities in biological milieu. Potentially, it could be applied in the diagnostics of SO 2 involved diseases.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2023
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IF 6.1
Zhiyong Xie,Ziqi Zeng,Guijie Chen,Wei Dong,Yujia Peng,Weiqi Xu,Yi Sun,Xiaoxiong Zeng,Zhonghua Liu
The intracellular polysaccharides of Aspergillus cristatus (IPSs) from Fuzhuan brick tea have been demonstrated to improve immune function linked to modulating the gut microbiota. Herein, to further investigate the efficacy of IPSs to maintain gut homeostasis, the protection of the purified fraction of IPSs (IPSs-2) on the mice with colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms were explored in this study. The results revealed that IPSs-2 alleviated the typical symptoms of colitis and suppressed the excessive inflammatory mediators, regulating the genes related to inflammatory responses in the colon at the mRNA level. Meanwhile, IPSs-2 treatment reinforced the intestinal barrier function by ameliorating the DSS-induced histological injury, facilitating the differentiation of goblet cells to enhance Mucin-2 generation, and enhancing the expression of tight junction proteins to alleviate colitis. In addition, IPSs protected against colitis by promoting the production of short-chain fatty acids (SCFAs), the activation of SCFAs receptors, and the leverage of the gut microbiota via the enrichment of Bacteroides, Parabacteroides, Faecalibacterium, Flavonifractor_plautii, and Butyricicoccus, linking with reducing inflammation and repairing intestinal barrier function. Overall, our research revealed the therapeutic potential of IPSs-2 as a prebiotic for attenuating inflammatory bowel disease and provided a rationale for future investigation.
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JOURNAL OF BIOTECHNOLOGY
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2019
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IF 3.163
Xiao-Ling Tang,Nan-Nan Zhang,Guo-Yan Ye,Yu-Guo Zheng
( R )-3-amino-1-butanol is a key intermediate of Dolutegravir for the treatment of HIV/AIDS and its green and efficient biosynthesis has attracted a great deal of attention. Transaminases are currently used as promising biocatalyst for the synthesis of chiral amines. However, many transaminases have ( S )-specificity and ( R )-selective transaminases were less exploited and studied, making the production of ( R )-amines remain challenging. In this study, a novel transaminase from Actinobacteria sp. ( As -TA) was obtained and applied for the biosynthesis of ( R )-3-amino-1-butanol by transferring the amino group from isopropylamine to 4-hydroxy-2-butanone. After optimization of the reaction condition and using a substrate fed-batch strategy, the conversion of 100, 200, 300, 400 and 500 mM 4-hydroxy-2-butanone reached 100%, 94.9%, 86.1%, 76.1% and 70.9%, respectively. ( R )-3-amino-1-butanol with a maximum yield of 29.6 g/L and 99.9% e.e. value was obtained. This was the first time demonstrating the successful biosynthesis of ( R )-3-amino-1-butanol with transaminase as biocatalyst and the obtained As -TA enriched the enzyme pool of transaminase with ( R )-specificity.
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BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
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2024
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IF 2.5
He Liu,Qian Gao,Kaiyue Zhang,Meng Xu,Hualei Wang,Dongzhi Wei
( R )-selective transaminases have the potential to act as efficient biocatalysts for the synthesis of important pharmaceutical intermediates. However, their low catalytic efficiency and unfavorable equilibrium limit their industrial application. Seven ( R )-selective transaminases were identified using homologous sequence mining. Beginning with the optimal candidate from Mycolicibacterium hippocampi , virtual mutagenesis and substrate tunnel engineering were performed to improve catalytic efficiency. The obtained variant, T282S/Q137E, exhibited 3.68-fold greater catalytic efficiency ( k cat / K m ) than the wild-type enzyme . Using substrate fed-batch and air sweeping processes, effective conversion of 100 mM 4-hydroxy-2-butanone was achieved with a conversion rate of 93 % and an ee value > 99.9 %. This study provides a basis for mutation of ( R )-selective transaminases and offers an efficient biocatalytic process for the asymmetric synthesis of ( R )-3-aminobutanol.
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ANALYTICAL LETTERS
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2017
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IF 1.15
Xiuping He,Jiangtao Wang,Xiaoqi Mei
A multitemplate molecularly imprinted polymer was synthesized using fragments similar to gonyautoxins 1 and 4 including 2,4,6-triaminopyrimidine, 4-hydroxy-2-butanone, and imidazole as dummy templates by bulk polymerization. Scanning electron microscopy and infrared spectroscopy showed a porous structure and the formation of organic groups in the imprinting process of the polymer. One millilitre of 0.1 mol L−1 acetic acid and 1 mL of 95% methanol were the optimized washing and eluting solutions during the molecularly imprinted solid-phase extraction. The adsorption capacity of the multitemplate molecularly imprinted polymer was lower than for the monotemplate molecularly imprinted polymer prepared in a previous study in seawater in which Alexandrium tamarense and Alexandrium minutum were cultivated. This result may due to the inappropriate combination of the dummy template fragments in the synthesis resulting in the unfitness of the imprinting sites for gonyautoxins 1 and 4. In general, it is inappropriate to use fragments with the similar parts to the analyte as the dummy templates. However, this work indicated the optimal molecularly imprinted polymer for the selective extraction of gonyautoxins 1 and 4.
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CHEMICAL ENGINEERING SCIENCE
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2015
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IF 2.337
Jun Mei,Jianyong Mao,Zhirong Chen,Shenfeng Yuan,Haoran Li,Hong Yin
The aim of this paper is to explore the reason for the catalyst-free phenomenon of synthesizing 4-hydroxy-2-butanone from formaldehyde and acetone under supercritical conditions and in high-temperature liquid-phase. Experiments were conducted in a tubular flow-type reactor at temperatures between 230 and 270 °C for residence times between 0.5 and 8 min. Under these conditions, a small amount of formic acid appeared via noncatalytic self-disproportionation of formaldehyde. The generated formic acid proved to play a role as catalyst in main reactions. A mechanism-based detailed chemical kinetics model for main reactions was suggested to assess the effect of temperature. This model applied well both under supercritical conditions and in high-temperature liquid-phase. The activation energies for forming and dehydration of 4-hydroxy-2-butanone were 97.5±3.5 kJ/mol and 120.6±5.8 kJ/mol, respectively.
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BIOORGANIC CHEMISTRY
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2024
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IF 4.5
He Liu,Shixi Wang,Meng Xu,Kaiyue Zhang,Qian Gao,Hualei Wang,Dongzhi Wei
( R )-selective transaminases show promise as catalysts for the asymmetric synthesis of chiral amines, which are building blocks of various small molecule drugs. However, their application is limited by poor substrate acceptance and low catalytic efficiency. Here, a potential ( R )-selective transaminase from Fodinicurvata sediminis (FsTA) was identified through a substrate truncating strategy, and used as starting point for enzyme engineering toward catalysis of 4-hydroxy-2-butanone, a substrate that poses challenges in catalysis. Molecular docking and dynamics simulations revealed Y90 as the key residue responsible for poor substrate binding. Starting from the variant (Y90F, mut1) with initial activity, FsTA was systematically modified to improve substrate-binding through active site reshaping and consensus sequence strategy, yielding three variants (H30R, V152K, and Y156F) with improved activity. A quadruple mutation variant H30R/Y90F/V152K/Y156F (mut4) was also found to show a 7.95-fold greater catalytic efficiency ( k cat / K M ) than the initial variant mut1. Furthermore, mut4 also enhanced the thermostability of enzyme significantly, with the T m value increasing by 10 °C. This variant also exhibited significantly improved activity toward a series of ketones that are either not accepted or poorly accepted by the wild-type. This study provides a basis for the rational design of an active to creating variants that can accommodate novel substrates.
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