JOURNAL OF BIOTECHNOLOGY
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2023
·
IF 4.1
Fang-Ying Zhu,Qing Yang,Min Cao,Ken Zheng,Xiao-Jian Zhang,Qi Shen,Xue Cai,Zhi-Qiang Liu,Yu-Guo Zheng
d -(−)-Pantolactone (DPL) is a key intermediate for the production of d -(+)-pantothenate (vitamin B5). Deracemization of d , l -pantolactone (D, L -PL) through oxidizing l -(+)-pantolactone (LPL) to ketopantoyl lactone (KPL) and subsequently reducing KPL to DPL is a promising route for synthesizing DPL. Herein, a newly mined l -pantolactone dehydrogenase from Rhodococcus hoagie ( Rho LPLDH) was used for the oxidative dehydrogenation of LPL. To alleviate inclusion bodies formed by membrane-bound Rho LPLDH intracellular expression in E. coli , strategies involving chaperone assistance and decreasing induction temperature were used to achieve Rho LPLDH soluble expression. To enhance its activity, directed evolution and hydrophilicity-based engineering yielded increased catalytic activity and thermostability . 1 M LPL was efficiently converted to KPL by engineering strain CM5 co-expressing Rho LPLDH L254I/V241I/I156L/F224Q/N164K and chaperone. A “two stages in one-pot” method was employed in deracemization of 1 M D, L -PL with 91.2% yield. These results demonstrated that CM5 catalyst exhibits great potential in enzyme cascade deracemization for the production of DPL.
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FOOD RESEARCH INTERNATIONAL
·
2023
·
IF 8.1
Xinyu Qiao,Han Li,Yunjiao Ma,Xianbing Xu,Junjie Yi,Hesham R. El-Seedi,Ming Du
Aquatic protein hydrolysates have many biological activities, but the off-flavor seriously decreases their commercial acceptability. Therefore, it is important to invest in finding an effective deodorization of aquatic hydrolysates that do not affect activities. In this study, ethanol pretreatment of mussel was applied to establish a new method to deodorize the blue mussel ( Mytilus edulis L. ) hydrolysates. LC-MS and GC–MS analysis results showed that 87.34% of fatty acids, 83.94% of aldehydes, most volatile flavor compounds including aldehydes, ketones, alcohols, acids, and hydrocarbons were decreased after ethanol pretreatment. Besides, it was found that the enzymatic hydrolysates of mussel with or without ethanol pretreatment showed high osteogenic activity, which induced an increase of 33.65 ± 4.36% and 31.77 ± 5.45% in MC3T3-E1 cell growth. These results suggest that ethanol pretreatment has beneficial potential for improving the flavor aspects of blue mussel peptides which may have the potential to stimulate bone regeneration and formation.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2023
·Vol. 27
·期 3
·753-761
·
IF 2.5
Chu Youqun,Zhang Huixuan,Zhou Huihui,Xu Tengfei,Yan Hui,Huang Zhangkao,Zhao Fengming
The nano-Ag–TiO 2 hollow microsphere precursors were prepared by the one-pot solvothermal method using L-tyrosine as the template agent and reducing agent. Subsequently, the nano-Ag–TiN hollow microsphere composites were formed by reducing nitride in an ammonia-filled atmosphere. The esterification of ethanol solvent and L-tyrosine microdroplet template generates traces of water in situ for the hydrolysis of alkane titanium. As the L-tyrosine microdroplet templates are sacrificed and incorporated into the titanium dioxide matrix, a hybridized hollow structure is formed. With the help of L-tyrosine, the surface of Ag–TiO 2 hollow microsphere precursors appeared folded rough surface, and the nanosilver was mostly distributed in the TiO 2 spherical shell. The constructed Ag–TiO 2 hollow microsphere demonstrated a good linear relationship between the current response value and the concentration in the range of 0.2–220 μM of H 2 O 2 , with the lowest detection limit of 0.04 μM. In the same concentration range, whereas the lowest detection limit of Ag–TiN hollow microsphere was 0.02 μM. The detection results of H 2 O 2 revealed that the Ag–TiN/HMS electrode has outstanding interference resistance, stability, and repeatability.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 33
·47887
·
IF 2.188
Tiantang Fan,Wuyou Ye,Beibei Du,Qin Zhang,Li Gong,Jiafeng Li,Shengli Lin,Zhongyong Fan,Qing Liu
A series of high-molecular-weight terpolymers named PTG- b -LG and PT- b -LG were synthesized based on the macroinitiators of PTG copolymers and PTMC, respectively. In vitro degradation of PTG- b -LG and PT- b -LG was carried out by immersing into PBS, in comparison with that of P L LA. Mass loss, water uptake, GPC, DSC, WAXD, and 1 H NMR were examined for the degradation study. It was found that PTG- b -LG degraded faster than PT- b -LG and P L LA due to the Di -random block structure, which had lower regularity of chain and lower crystallinity. The compositional changes appeared to be more complex, but the molar mass decreased owing to chain fragmentation caused by hydrolysis. Moreover, morphological changes were also observed during the degradation in all situations with the crystallization of by-products and a preferential degradation of amorphous domains. Specifically, PTG- b -LG presented an adjustable degradation rate and may be used for the fabrication of totally biodegradation stents in the future. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47887.
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MOLECULES
·
2019
·Vol. 24
·期 15
·2770
·
IF 3.06
Yunchang Fan,Zeyu Niu,Chen Xu,Lei Yang,Tuojie Yang
Rheum palmatumL. (R. palmatumL.) is a traditional Chinese herb and food, in which rhein and emodin are the main bioactive components. The extraction of the two compounds fromR. palmatumL. is, thus, of great importance. In this work, protic ionic liquids (PILs) were applied in the microwave-assisted extraction (MAE) of rhein and emodin fromR. palmatumL., which avoids the toxicity of organic solvents. The results of the present study indicate that PILs possessing higher polarity exhibit higher extraction ability due to their stronger absorption ability for microwave irradiation. Compared with conventional solvents, such as methanol, trichloromethane, and deep eutectic solvents (DESs), the PIL, 1-butyl-3-himidazolium methanesulfonate ([BHim]MeSO3) reported herein is more efficient. The selected extraction conditions of liquid–solid ratio, microwave irradiation time, microwave irradiation power, and PIL concentration were 40 g·g−1, 50 s, 280 W, and 80%, respectively. Under the selected conditions, the extraction yields of rhein and emodin were 7.8 and 4.0 mg·g−1, respectively. These results suggest that PILs are efficient extraction solvents for the separation of active components from natural products.Keywords:microwave-assisted extraction;protic ionic liquids (PILs);polarity;Rheum palmatumL.
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CHIRALITY
·
2019
·Vol. 31
·期 10
·824-834
·
IF 1.927
Shiyu Chen,Xiaoxia Huang,Shun Yao,Wencai Huang,Yin Xin,Minghui Zhu,Hang Song
Several amino acid chiral ionic liquids were introduced as functional monomers to prepare molecularly imprinted polymers for specific recognition of L-phenylalanine. Among them, the imprinted polymers L-Phe@MIPs based on [ViImC3][L-Pro] showed the best selective recognition ability for L-phenylalanine. A series of experiments such as dynamic adsorption, static adsorption, and competitive adsorption were conducted to investigate the specific recognition ability and adsorption capacity of the L-Phe@MIPs. It is found that the adsorption efficiency to L-phenylalanine on L-Phe@MIPs was 3.11 times higher than that to D-phenylalanine. All the results demonstrated that the L-Phe@MIPs possessed good recognition and relatively high adsorption efficiency for L-phenylalanine. Besides, the recovery of L-phenylalanine was above 98%, and the L-Phe@MIPs exhibited good reusability.
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JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Heng Mao,Hong-Gang Zhen,Ali Ahmad,Shen-Hui Li,Yue Liang,Jun-Fan Ding,Yao Wu,Lin-Zhi Li,Zhi-Ping Zhao
High separation performance and superior mechanical properties of the membranes are both of critical importance for membrane modules to achieve high efficiency and long-term stability. Herein, a series of mixed matrix membranes (MMMs) with brick-and-mortar architecture are prepared by incorporating two-dimensional zeolitic imidazolate framework-L (ZIF-L) nanosheets into polydimethylsiloxane (PDMS) matrix for separating alcohols (ethanol, n -propanol or n -butanol) from aqueous solution. The unique leaf-like morphology, flexible pore structure , and high hydrophobicity of ZIF-L nanosheets allow the straight and preferential permeation for alcohols; while the brick-and-mortar architecture renders the tortuous and intricate pathways for water, thus improving the membrane selectivity. Incorporating ZIF-L nanosheets endows the membranes with outstanding pervaporation performance, together with unusual and favorable increase in mechanical properties. More interestingly, the subtle interconnection of ZIF-L nanosheets creates the relatively continuous pathways for penetrants. Consequently, the resultant membrane displays a high separation factor (57.6) and a comparable permeation flux (402 g m −2 h −1 ) in separating 1.0 wt% n -butanol aqueous solution at 40 °C. Furthermore, the presence of ZIF-L nanosheets donates good thermal properties and promising long-term stability to the membranes. The findings of engineering brick-and-mortar architecture through two-dimensional porous fillers may provide new insights into designing high-performance MOF-based membranes for various applications.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Longhua Ding,Zhongyao Zhao,Dongjun Li,Xue Wang,Jialin Chen
A simple and highly efficient “off-on” fluorescent sensor based on grapheme quantum dots (GQDs) for Cu 2+ was developed. In this sensing platform, the fluorescence of GQDs was quenched in the presence of 2,4-dinitrophenylcysteine (DNPC), which is the reaction product of 1-chloro-2,4-dinitrobenzene (CDNB) and l -cysteine, owing to the spectral overlap between the absorption of DNPC and the excitation of GQDs. In the presence of Cu 2+ , l -cysteine was catalytically oxidized to l -cystine by O 2 , resulting in the reduction of DNPC. Thus, the fluorescence of GQDs was recovery. Based on this, the fluorescent detection of Cu 2+ could be achieved. The proposed sensing strategy offered a selective identification of Cu 2+ with a detection limit of 4.5 nM. Additionally, the practical application of this assay for Cu 2+ determination in real water samples was also demonstrated.
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TALANTA
·
2019
·
IF 4.916
Hongyuan Wang,Chunmao Chen,Yongli Liu,Yalin Wu,Yongyong Yuan,Qingxiang Zhou
2,4,6-Trinitrophenol (TNP) is a common explosive and widely used in military, pharmaceutical, pesticide, printing and dyeing industries. TNP in the wastewater and waste residues will enter into the environment by various ways and lead to serious threat on the environment. It is urgent to develop simple and robust analytical methods for highly sensitive and selective determination of TNP. L -cysteine-coated cadmium sulfide quantum dots (L-Cy-CdS QDs) with strong fluorescence were synthesized at room temperature and characterized by ultraviolet visible absorption spectra, transmission electron microscopy and fourier transform infrared spectrometer. TNP could quench the fluorescence of quantum dots based on the favorable electronic energy transfer , fluorescence resonance energy transfer, and electrostatic interactions . The effects of pH, reaction time and L-Cy-CdS QDs concentration on the fluorescence response were optimized. It was found that the fluorescence quenching of the quantum dots was linear with the concentration of TNP in the range of 0.05–5 μg mL −1 , and the limit of detection was as low as 39 ng mL −1 . The method can be applied to the quantitative detection of TNP in environmental water samples.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Chengdong Yang,Mi Zhou,Yi Lin,Chong Cheng,Fei Cheng,Wenlong Liu,Puxin Zhu
Super-tough poly ( l -lactide) (PLLA) without compromising its biodegradability and biocompatibility was fabricated by reactive blending with PLLA and maleic anhydride grafted starch (MS)/poly (ethylene glycol) diacrylate (PEGDA). PEGDA as reactive compatibilizer exhibits higher compatibilization efficiency and significant plasticization effect in PLLA matrix. Fourier transform infrared spectroscopy (FT-IR) confirmed that PEGDA monomer successfully located at the molecules of MS and some interesterification reactions occurred between PEGDA and PLLA. The ductility of PLLA materials were significantly improved, for example, the elongation of break increased to 298% at the optimum PLLA/MS/PEGDA content. Dynamic mechanical thermal analysis (DMTA) demonstrated the glass transition temperature of blends decreased with the contents of MS/PEGDA increasing. The differential scanning calorimeter (DSC) results revealed that cold crystallization temperature and melting temperature of blends were decreased with the augment of the contents of MS/PEGDA. Wide angle X-ray diffraction (WARD) and DSC certified that a high crystalline article was obtained through practical extrusion process, which could propagate shear yielding deformation to dissipate energy during tensile fracture. Scanning electron microscope (SEM) demonstrated that the blends with PEGDA did not exhibit a visible phase-separated morphology from cryogenic fractured surfaces compared with the blend without PEGDA.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Matteo Ciprian,Karla Hernandez Ruiz,Meruyert Kassymova,Tingting Wang,Serge Zhuiykov,Somboon Chaemchuen,Rong Tu,Francis Verpoort
3D metal N-doped carbon frameworks (M-NCFs) are produced from the direct pyrolysis of 2D zeolitic imidazolate frameworks (ZIF-L Zn and Co) in a reducing atmosphere. The effects of the thermal treatment were studied in order to achieve the desired catalyst. The results show that metal nanoparticles and N-doping species present in the carbon matrix have a direct influence on the catalytic performance. Zn/NCF-1000 displayed quantitative conversion and selectivity towards the chemical fixation of carbon dioxide through the cycloaddition with epoxides. Furthermore, the magnetic property of the newly synthesized Co/NCF-600 was used to demonstrate its superior stability and recyclability, retaining the same catalytic activity for more than 10 cycles.
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ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Keqin Deng,Hao Wang,Jing Xiao,Chunxiang Li,Shaowei Zhang,Haowen Huang
A sandwich-type photoelectrochemical (PEC) immunosensor was constructed for sensitive detection of prostate specific antigen (PSA). It was based on electrochemically reduced graphene oxide-TiO 2 (ERGO-TiO 2 ) as photoelectrochemical platform to immobilize capture antibody (Ab 1 ). Then, quinone-rich polydopamine nanospheres (PDANS) loaded detection antibody (Ab 2 ) and photocurrent signal label, l -cysteine-coated cadmium sulfide quantum dots (CdSQDs). ERGO-TiO 2 displayed greatly improved photocurrent response to white light. CdSQDs conjugated with PDANS further amplified photocurrent signal because of the good conductivity of PDANS and ERGO. The increased photocurrent showed a linear correlation with PSA in the concentration range from 0.02 pg mL −1 to 200 ng mL −1 with the detection limit of 6.8 fg mL −1 . It also revealed high selectivity and good stability.
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危险品化学品经营许可证（带存储）