AIP Advances
·
2024
·Vol. 14
·期 11
·
IF 1.4
Liu Xiao-Bin,Dai Xiao-Hua,Li Li,Shen Jing,Li Wei,Li Chang-Yi
Enterococcus faecalis ( E. faecalis ) is one of the dominant bacteria in infected root canals, and it is tolerant to commonly used root canal disinfectants. Ag + has a certain antibacterial effect on E. faecalis , but the instability and potential toxicity of Ag + limit its application. Metal azolate framework-7 (MAF-7) is a typical metal–organic framework that has been used for drug delivery due to its high encapsulation efficiency, tunable release profile, and low cytotoxicity. In this study, we used a simple method for the synthesis of Ag + /MAF-7 nanocomposites. After characterization via several techniques, the antibacterial activity of this nanocomposite against E. faecalis was investigated. Ag + was found to be uniformly bound to MAF-7, and the resulting Ag + /MAF-7 nanocomposite showed significant antibacterial activity against E. faecalis . This study demonstrates the potential application of nanocomposite antibacterial materials in treating infected root canals.
研究领域:
牙科学
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微生物学
·
纳米医学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2021
·
IF 0.782
Jue Chen,Tengmei Gao,Yinxia Chang,Yanming Wei,Yonghui Wang
Folate (FA) plays a key role in the biosynthesis of amino acids, purines, and pyrimidines in the human body, and intracellular folate metabolism has become an attractive target of tumor chemotherapy. In this work, an inclusion interaction was found between FA and cucurbit[7]uril (CB[7]), and the formation of a CB[7]-FA 2:1 supramolecular inclusion complex was confirmed by fluorescence spectra, UV-Vis absorption spectroscopy, 1H NMR, and molecular modeling calculations. In addition, FA is generally determined through the indirect fluorescent method because it shows weak fluorescence in aqueous solution. Therefore, a simple, direct fluorescence probe method for rapidly measuring FA was investigated, and the linear equation of FA was ΔF = 14.691C + 37.366 within the concentration ranges of 0.82 ~ 18.31 µg mL–1. The proposed direct fluorescence method was applied to the determination of spiked plasma. We demonstrated that this method could provide an experimental basis for the targeted administration of the CB[7]-FA complex, and it could be extended as a promising fluorescence detection method for drugs in vivo.
研究领域:
生物化学
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分析化学
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药物化学
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产品关联
DOI
高影响因子
Bioresources and Bioprocessing
·
2025
·Vol. 12
·期 1
·1-18
·
IF 5.1
Zhang Rui,Wang Han,Wang Li,Zheng Zhiming
Menaquinone-7, a form of vitamin K 2 , plays a critical role in the treatment of hemorrhagic diseases caused by vitamin K deficiency and in the prevention of bone fractures. Microbial fermentation has emerged as a promising method for MK-7 production due to its high product optical purity and significant physiological activity. However, the current production efficiency of MK-7 remains insufficient to meet industrial demands. In this study, we employed a combination of single-factor experiments, Plackett-Burman design, steepest ascent experiments, and Box-Behnken design to optimize the fermentation medium for MK-7 production by Bacillus subtilis BS - Δ ackA . Through regression analysis and consideration of practical production constraints, the optimal fermentation medium parameters were determined as follows: 20 g/L sucrose, 20.7 g/L glycerol, 47.3 g/L soy peptone, 4 g/L yeast extract, and 1.9 g/L KH 2 PO 4 , 0.1 g/L MgSO 4 ·7 H 2 O. Under these optimized conditions, the MK-7 yield reached 154.6 ± 1.32 mg/L. The experimental results demonstrated excellent stability and reliability, aligning closely with the model predictions. This study significantly enhances MK-7 production at the shake-flask fermentation level, providing valuable insights for large-scale industrial applications.
研究领域:
微生物发酵
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生物技术
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生物工程
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应用微生物学
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营养科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemPlusChem
·
2020
·Vol. 85
·期 4
·679-683
·
IF 2.753
Shengke Li,Kit Ieng Kuok,Xia Ji,Anni Xu,Hang Yin,Jun Zheng,Huaping Tan,Ruibing Wang
Graphical Antibacterial switch : The capability of cucurbit[7]uril (CB[7]) in modulating the antibacterial activity of ambroxol hydrochloride (ABX) was successfully demonstrated by using two strains of Pseudomonas aeruginosa and Escherichia coli . The antibacterial activity of ABX was “turned off” upon encapsulation by CB[7] and “turned on” after ABX was released from the CB[7]-ABX host–guest complex upon addition of a competitive guest amantadine hydrochloride. Supramolecular encapsulation by cucurbit[7]uril (CB[7]) was recently demonstrated to provide a simple and efficient method for antibacterial activity regulation of antibiotics. In this work, CB[7] was shown to form binary host-guest complex with ambroxol hydrochloride (ABX), a clinical mucokinetic and expectorant drug, which was reported to exhibit certain antibacterial activity. 1 H NMR titration and isothermal titration calorimetry experiment results suggested that the 4-hydroxyl cyclohexylamine group of ABX was included inside the CB[7] cavity, with a binding constant K a of (6.69±0.11)×10 5 M −1 in phosphate buffered saline (PBS) solution, thermodynamically driven by both enthalpy change (ΔH=−12.2 kJ/mol) and entropy change (TΔS=21.1 kJ/mol). More importantly, ABX's inhibitory activity (MIC 50 ) against bacillary strains towards Pseudomonas aeruginosa and Escherichia coli strains was decreased from (5.11±0.31)×10 −6 M −1 and (2.63±0.34)×10 −5 M −1 to zero upon encapsulation by CB[7], and was subsequently recovered to almost its original activity when a competitive guest, amantadine hydrochloride, for disassembling CB[7]-ABX complex, was added, suggesting that the antibacterial activity of ABX could be readily “turned off/on” upon its complexation and decomplexation with CB[7].
研究领域:
药理学
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微生物学
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化学
✓ 已验证
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2017
·
IF 2.234
Jianguo Xu,Jiangang Yu,Yi Jin,Jie Li,Zhiqun Yu,Yanwen Lv
A new procedure of microwave-assisted organic synthesis in flow was designed and introduced for Fischer indole synthesis of 7-ethyltryptophol (7-ET). By using back-pressure regulator (BPR), a reaction temperature of 180 °C could be easily and readily achieved even in a low-boiling solvent [water/ethylene glycol(EG)]. At this temperature, the synthesis of 7-ET from 2-ethylphenylhydrazine and 4-hydroxybutanal in flow was successful (78% net yield) and practical (short residence time: 30 s) with a simple purification process of extraction.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Xiaolu Wang,Jinxun Chen,Manquan Fang,Tao Wang,Lixin Yu,Jiding Li
In this contribution, zeolitic imidazolate framework (ZIF-7)/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) with uniformly dispersed ZIF-7 were fabricated. The homogeneous dispersion of ZIF-7 nanoparticles in PDMS matrix and better interface compatibility were characterized by SEM and EDS. PV performance reveals that the MMMs display increased total flux and the highest separation factor occurs at 20 wt% ZIF-7 loading, which were 1689 g m −2 h −1 and 66 respectively as compared to 1080 g m −2 h −1 and 51 for pure PDMS membrane when separating 1 wt% butanol aqueous solution at 60 °C. The total flux reaches 3496 g m −2 h −1 with 80 wt% butanol in permeate for the enrichment of 5 wt% butanol solution at 60 °C. The enhanced flux may result from enlarged free volume in the polymer matrix caused by the incorporation of ZIF-7 nanoparticles. Moreover, the super-hydrophobic ZIF-7 pore channels and butanol preferential permeation may contribute to the improvement of separation factor. The result also shows that there is a 21.1% reduction of energy barrier for penetrant transportation for 20 wt% ZIF-7 filled PDMS membrane as compared to pristine PDMS membrane. A long period of pervaporation experiment was also carried out to investigate the structure stability of the ZIF-7/PDMS membrane, and the MMM remains intact during the 240 h continuous operation, which is the key to industrial application for membrane-based separation process. All above indicated that ZIF-7 is a good filler to fabricate butanol permselective pervaporation membranes for butanol separation and enrichment.
研究领域:
材料科学
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化工分离技术
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产品关联
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2013
·Vol. 8
·期 2
·162-168
·
IF 0.886
Xie Jiangkun,Yan Naiqiang,Liu Fei,Qu Zan,Yang Shijian,Liu Ping
Porous ZIF-7 with the sodalite (SOD) cage structure (ZIF, Zeolitic imidazolate framework) were synthesized by the solvothermal method. Synthesized material was characterized by powder X-ray diffraction (PXRD), thermal gravity (TG), scanning electron microscopy (SEM) and N 2 adsorption analysis. ZIF-8 with the SOD structure and a little larger pore window was synthesized in a similar way and was characterized for comparisons. Thermal stability and structural stability of ZIF-7 were tested through PXRD analysis, and the capability of the material for CO 2 capture from simulated flue gas was investigated through physical adsorption method. The results showed that CO 2 adsorption capacity on ZIF-7 was about 48 mL·g −1 while the capacity on ZIF-8 was about 18 mg·g −1 (at 12°C and 0.98 P / P
0 relative pressure). Furthermore, the impact of flue gas components on adsorption capacity of ZIF-7 and the selectivity of CO 2 against N 2 on ZIF-7 was also investigated in this work.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Bioresources and Bioprocessing
·
2015
·Vol. 2
·期 1
·1-9
·
IF 0
Huang Xiaomei,Cao Xuejun
Background Ursodeoxycholic acid (UDCA) is an important clinical drug in the treatment of liver disease. In previous work, ursodeoxycholic acid was prepared by traditional organic synthesis. The preparation of ursodeoxycholic acid through an electrochemical method with higher stereoselectivity and environmental friendliness is described herein. Results Dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and N -methyl-2-pyrrolidone (NMP) were used as stereoselectivity additives during electroreduction. With 107.5 mM DMSO in methanol containing potassium bromide and a continuous current of 20 mA, 936 Coulombs was passed into the electrolysis system, achieving 88.5 % conversion of 7-ketone lithocholic acid (7K-LCA), while the yield of UDCA reached 72.8 %. Cyclic voltammetry (CV) was used to explore the electrochemical behavior of the reaction, and the electrolysis results were consistent with the cyclic voltammograms. Conclusions Ursodeoxycholic acid can be prepared by electroreduction with high stereoselectivity. The method developed here offers a potential application for large-scale production of ursodeoxycholic acid and an interesting reference to asymmetric electrochemical reduction of the keto group.
研究领域:
药学
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有机化学
✓ 已验证
产品关联
DOI
JOURNAL OF CHROMATOGRAPHY A
·
2014
·
IF 4.258
Liyun Ma,Si-Min Liu,Lin Yao,Li Xu
Cucurbit[7]uril (CB7), one host macromolecule, possesses a hydrophobic inner cavity and two identical hydrophilic carbonyl fringe portals, thus interacting with a variety of guest molecules through hydrophobic, hydrogen bonding and ion–dipole interactions. These characteristics make CB7 a good candidate as the stationary phase (SP) modifier in high performance liquid chromatography (HPLC). In the present work, CB7 was immobilized onto silica (CB7-SiO 2 ) by a sol–gel approach. The obtained CB7-SiO 2 was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and elemental analysis. The chromatographic performance of CB7-SiO 2 was then studied in detail, in both reversed phase (RP) and hydrophilic interaction liquid chromatographic (HILIC) modes. For probe aromatic compounds and dyes, the typical RP behavior was observed, mainly due to the predominant hydrophobic interaction between the analytes and CB7-SiO 2 . For probe alkaloids, the “U-shape” curves were obtained; in the methanol-rich part, HILIC performance was obvious, probably owing to hydrogen bonding and ion–dipole interactions. Compared to bare SiO 2 SP, the stronger retention and different selectivity were observed on CB7-SiO 2 . The CB7-SiO 2 SP remained stable within at least 11,000 column volumes of the MP, revealing the satisfactory stability of it. The proposed method integrated the advantages of CB7 and sol–gel method provided a feasible way for the wider application of CBs in separation science.
研究领域:
分析化学
·
分离科学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 36
·28394-28400
·
IF 3.84
Yunpan Ying,Yuanlong Xiao,Jing Ma,Xiangyu Guo,Hongliang Huang,Qingyuan Yang,Dahuan Liu,Chongli Zhong
Metal–organic frameworks (MOFs) have exhibited promising applications in gas and liquid separation. As a subclass of MOFs, zeolitic imidazolate frameworks (ZIFs) are attracting more and more interest because of their unique thermal and chemical stability. One of the representative ZIFs, ZIF-7, has super-hydrophobic pores, making it a perfect filler in polymer membranes for recovering acetone from fermentation broths. In this study, mixed matrix membranes (MMMs) based on ZIF-7 and polydimethylsiloxane (PDMS) were prepared, which display improved acetone–water total flux and separation factors simultaneously compared with a pure PDMS membrane. The separation factor can reach up to 39.1 with a high flux of 1236.8 g m−2 h−1 at 333 K, which is the highest value among those reported up to now to the best of our knowledge.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2014
·Vol. 31
·期 7
·1276-1280
·
IF 1.241
Yuan Xiangxi,Ma Xiaolei,Cao Xuejun
A novel method of producing ursodeoxycholic acid was developed through direct electro-reduction of 7-ketolithocholic acid in a divided electrolytic cell. Titanium ruthenium mesh electrode was used as the anode, while high purity lead plate was used as the cathode. The process was optimized with regards to the electrolyte, temperature, concentration of methanol, current density and concentration of anolyte. When potassium bromide was used as the electrolyte, the saturated solution of 7-ketolithocholic acid in 85–93% (v/v) methanol, current density 9.52–28.6 A/m 2 and concentration of anolyte at 4–6% (w/w), the maximum percentage yield of ursodeoxycholic acid could be 47%. The method will provide a potential approach for large-scale production of ursodeoxycholic acid.
研究领域:
药学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2023
·
IF 4.4
Xiaoliang Wang,Yibo Li,Yan Liu,Qian Wu,Zunxi Huang,Shukun Tang,Junmei Ding
The newly semi-synthetic β -lactam antibiotics play critical roles in prevention and treatment of β -lactam antibiotic-resistant bacteria. Acetyl xylan esterases belong to carbohydrate esterase 7 family can specifically hydrolyze 7-aminocephalosporanic acid (7-ACA) to produce deacetyl-7-aminocephalosporanic acid (D-7ACA) which is one of the most important starting materials to synthesize newly semi-synthetic β -lactam antibiotics. Here, an effective acetyl xylan esterase, ThAXE, from Thermobifida halotolerans YIM 90462 T , was firstly identified and characterized. ThAXE exhibited its highest catalytic activity against p -nitrophenyl acetate ( p -NPC 2 ) at pH 8.5 and 50 °C, with K m and K cat / K m were 1.0 ± 0.1 mM and 2262.9 mM −1 s −1 , respectively. Additionally, ThAXE can hydrolyze the acetyl group of 7-ACA at its C3' position with the specific activity of 7.4 U mg −1 . Furthermore, molecular docking combined with site-directed mutagenesis validation demonstrated that the pocket of catalytic residues Ser186, Asp272, and His301 could accommodate p -NPC 2 and 7-ACA ligands. This is the first report of a novel acetyl xylan esterase from T. halotolerans that has considerable potential biotechnological values.
研究领域:
生物化学
·
微生物学
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生物技术
·
酶学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）