JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2018
·
IF 2.441
Yilin Sun,Le Zhen,Ying Peng,Jiankun Wang,Fei Fei,Lixiang Aa,Wenjiao Jiang,Xue Pei,Li Lu,Jie Liu,Guangji Wang,Kun Hao
To improve bioavailability and provide resistance to deamination , an array of gemcitabine (dFdC) prodrugs carrying the acyl modifications has been successful in the optimization of pharmacokinetic properties of dFdC, but the reports about 4- N -carbobenzoxy-dFdC (Cbz-dFdC), a dFdC prodrug bearing alkyloxycarbonyl modification, are relatively rare. Notably, in vivo enzymatic hydrolysis was an absolutely essential factor for the activation of these prodrugs, which is correlated with the anti-tumor activity. Therefore, detailed metabolism studies of Cbz-dFdC should be carried out for a more authentic pharmacodynamic evaluation. In order to detect the pharmacokinetic characteristics of Cbz-dFdC, a selective, sensitive and accurate method for the simultaneous determination of Cbz-dFdC, along with dFdC and its major metabolite dFdU in rat plasma was developed and validated using UFLC–MS/MS techniques. Column was at 40 °C for separation using an eluent with acetonitrile and 0.1% formic acid , 1 mM ammonium formate at a flow rate of 0.2 mL/min. Detection was performed using ESI source in positive ion selected reaction monitoring mode by monitoring the following ion transitions m / z 398.1 → 202.2 (Cbz-dFdC), m / z 264.1 → 112.0 (dFdC), m / z 265.3 → 113.2 (dFdU) and m / z 246.1 → 112.0 (IS). Analytes were extracted by simple precipitation with acetonitrile containing internal standards followed by liquid-liquid extraction with ethyl acetate . The calibration curves of Cbz-dFdC, dFdC and dFdU were linear in the concentration range of 2 to 500 ng/mL, 2 to 500 ng/mL and 40 to 10,000 ng/mL, respectively. The assay ranges selected for the three analytes were appropriate and minimized the need for reanalysis. All the validation data, such as intra- and inter-day precision, accuracy, selectivity and stability, were within the required limits. In conclusion, the sensitive analytical assay was selective and accurate for the determination of rat plasma concentrations of Cbz-dFdC, dFdC and dFdU from a single LC–MS/MS analysis and well-suited to support pharmacokinetic studies.
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高影响因子
OPTIK
·
2013
·
IF 0.524
Zhijuan Cao,Fengxian Qiu,Qing Wang,Guorong Cao,Lin Zhuang,Qiang Shen,Xiaolong Xu,Jie Wang,Qian Chen,Dongya Yang
The azo benzothiazole polyurethane–urea (ABPUU) was synthesized from chromophore molecule 4-[(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3-diamine NBDPD, polyether polyol (NJ-210) and isophorone diisocyanate (IPDI). The structure, thermal property , mechanical property and physical property were characterized and investigated. The refractive index ( n ) and thermo-optic coefficient (d n /d T ) of ABPUU was determined at different temperature and wavelength (532 nm, 650 nm and 850 nm) using attenuated total reflection (ATR) technique. Using the CCD digital imaging devices, transmission loss of ABPUU was measured. A 1 × 2 Y-branched and 2 × 2 Mach–Zehnder interferometer (MZI) switch with two rib waveguides , dual driving electrodes and two critical 3-dB couplers polymeric thermo-optic switches based on thermo-optic effect of prepared ABPUU were designed and simulation. The power consumption of the Y-branched switch is less than 0.84 mW. The Y-branched and MZI switching rising and falling times obtained are 0.8 ms and 0.2 ms, respectively.
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高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
·
2025
·
IF 3.6
Wenzhe Ma,Wanqing Wei,Jian Wen,Cong Gao,Guipeng Hu,Xiaomin Li,Jia Liu,Jing Wu,Wei Song
The synthesis of tertiary amides is crucial in pharmaceutical manufacturing, but achieving this efficiently through enzymatic methods remains challenging. Here, we describe the screening, evolution, and application of a lactamase for the synthesis of 2-(2-oxopyrrolidin-1-yl)-butanoic acid (2-OYBA) in aqueous phase. Through database mining, we identified a lactamase from Paraburkholderia xenovorans ( Px AmpC) with the highest amide synthesis activity in this study at 31.3 U/g. Using protein crystallization, molecular dynamics simulations, and quantum mechanics calculations, we proposed and verified three potential synthesis mechanisms for 2-OYBA. We identified a mechanism for synthesis of 2-OYBA involving adenylation and lactamization, with the carboxyl group in the intermediate 2-2 (INT2-2) acting as a proton shuttle. Guided by this mechanism, rational design efforts enhanced amide synthesis activity by 16.6-fold. The Px AmpC mutants also exhibited a broader substrate scope for amide bond synthesis compared to the wild type. Our findings advance the green synthesis of complex amide compounds.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Xiaochen Qi,Fuli Li,Chih-Huang Weng,Kai Liu,Renchuan Fu,Na Liu,Longzhen Ding
2-(2-Hydroxy-5-methylphenyl) benzotriazole (UV-P), a high-production and structurally complex benzotriazole derivative, has an uncertain degradation pathway and transformation dynamics in aquatic environments, raising concerns about its potential toxicological risks to human health and the ecological systems. This study investigated the oxidative degradation of UV-P by ferrate(VI) in aqueous solution under controlled experimental conditions. The results demonstrated that ferrate(VI) efficiently degraded UV-P under alkaline conditions, achieving a maximum removal efficiency of 91.76 % at pH 8.0. Furthermore, the influence of various environmental factors, including pH, oxidant dosages, inorganic ions (HCO 3 − , Cl − , Br − , NO 3 − , Ca 2+ , K + , Mg 2+ , and NH 4 + ), and humic acid, on the ferrate(VI)-mediated oxidative degradation of UV-P were systematically examined. The results indicated that although inorganic ions and humic acid partially inhibited the degradation process, a satisfactory degradation efficiency was still attained. The intermediate identification results indicated that the ferrate(VI)-mediated oxidative degradation of UV-P primarily proceeded via bond cleavage, oxygen atom transfer, and radical coupling reactions, resulting in the formation of cleavage products, hydroxylated derivatives, and polymeric compounds. The oxidative degradation pathway of UV-P and key reactive sites targeted in the ferrate(VI) degradation system were examined through quantum chemical methods, including analyses of atomic charge distribution and frontier electron density. The toxicity assessment highlighted the need to focus on the chronic toxicity of specific aminated degradation products. This study is essential for elucidating the degradation mechanism of the benzotriazole compound UV-P in aquatic environments and comprehensively assessing its potential biotoxicity.
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高影响因子
KEY ENGINEERING MATERIALS
·
2015
·
IF 0
Yang Yi Chen,Qi Zhong,Tao Chen,Ji Ping Wang
The cotton fabrics with enhanced cleaning capability were prepared by grafting thermo-responsive random copolymer poly (2-(2-methoxyethoxy) ethoxyethyl methacrylate-co-acrylic acid), abbreviated as P(MEO2MA-co-AA), to the amino modified cotton fabrics. ATR-FTIR measurement confirmed the immobilization of P(MEO2MA-co-AA) to the cotton fabrics. Equilibrium swelling ratio indicates that the cotton fabric with grafted P(MEO2MA-co-AA) possesses thermo-responsive ability .The enhanced cleaning capability was investigated by the decontamination experiments probed with confocal microscope. The results show the cleaning capability can be prominently improved when the cleaning temperature is lower than the LCST of P(MEO2MA-co-AA).
研究领域:
材料科学
·
纺织工程
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KEY ENGINEERING MATERIALS
·
2015
·
IF 0
Jie An,Yang Yi Chen,Lei Mi,Ji Ping Wang,Qi Zhong
Thermo-responsive random copolymer poly (2-(2-methoxyethoxy) ethoxyethyl methacrylate-co-ethylene glycol methacrylate) P(MEO2MA-co-EGMA) was investigated in thin film. By spin-coating, the obtained film thickness varied from 9 nm to 97 nm, which shows a linear relationship with tetrahydrofuran solution concentration. The swelling and transition behavior of P(MEO2MA-co-EGMA) films were monitored by white-light interferometry under water vapor atmosphere. It is observed that the film rapidly swelled in the first 90 min. Afterwards it reached an equilibrium state. The film thickness did not show a prominent increase by further prolonging the swelling time. In addition, the swelling capability of P(MEO2MA-co-EGMA) films was related to the film thickness. The thicker film possessed less swelling capability. Unlike the transition behavior in aqueous solution, P(MEO2MA-co-EGMA) films showed a much broader transition region, which might be related to the influence of Si substrate.
研究领域:
高分子科学
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材料化学
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薄膜技术
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智能材料
·
表面与界面科学
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DOI
JOURNAL OF MOLECULAR STRUCTURE
·
2020
·
IF 2.463
Shaoping Feng,Kun Huang,Zhangjie Huang,Guiyang Liu,Guowei Zhang,Gaozhang Gou
ABSTRACT In view of the separation and recycling of Pd(II) from multi-metal aqueous solution, a functionalized extractant of 2-[(2-ethylhexyl)thio]benzoxazole (EHBXS) with excellent selectivity for Pd(II) was synthesized and used to extract Pd(II) for the first time. The effects of EHBXS concentration, HCl concentration, organic/aqueous (O/A) phase ratio, contact time, and regeneration of EHBXS were investigated in detail. The extraction efficiency of Pd(II) was almost 100 % while the co-extraction efficiencies of Pt(IV), Rh(III), Cu(II), Fe(III) and Ni(II) existed in the aqueous solution were less than 10 %, which indicates that EHBXS is an effective extractant and can effectively remove Pd(II) from other metals at desired extraction conditions. Thiourea ((NH 2 ) 2 CS) solution (1.0 mol/L) could be used as an effective Pd(II) stripping agent and the one-step stripping efficiency of Pd(II) was higher than 98 %. EHBXS has excellent regeneration ability and the extraction efficiency of Pd(II) with regenerated EHBXS reaches to 87% even after 7 cycles. Moreover, the coordination mechanism between EHBXS and Pd(II) has been proven via the slope method, FT-IR spectra, 1 H NMR, 13 C NMR and single X-ray diffraction. Pd(II) and EHBXS formed a 1:2 complex of Pd(EHBXS) 2 Cl 2 during extraction. Pd(II) was coordinated with two Cl atoms and two EHBXS, and thus formed Pd(EHBXS) 2 Cl 2 molecule, in which EHBXS was coordinated with Pd(II) via the N atom in the benzoxazole ring as neutral unidentate ligand.
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高影响因子
OPTIK
·
2020
·
IF 2.187
Tongpeng Zhao,Shaohua Ji,Degao Zhong,Fei Teng,Shakir Ullah,Siyuan Hu,Jie Tang,Bing Teng
The organic nonlinear optical (NLO) material N, N-dimethyl-4-[2-(2-quinolyl) vinyl] aniline (DADMQ) has been synthesized and high-quality single crystal with the dimension of 8 × 1 × 0.5 mm 3 was grown from methanol solvent by slow cooling method for the first time. Single crystal and powder XRD studies show that DADMQ crystal belongs to the orthorhombic space group Pna2 1 . All the functional groups and structure of the synthetic material can be determined from FT-IR and 1 H NMR spectral analyses. The thermal properties can be studied through TG/DTG and DSC analyses, and its melting point is confirmed at 184.9 ℃. Some critical optical characteristics like the optical transmittance, optical absorption coefficient (α), energy band gap ( E g ), cut-off wavelength (λ max ) and extinction coefficient (κ) can be carried out through UV–vis-NIR spectral analysis. The dielectric features of the title crystal have also been measured. Furthermore, there is a blue emission appeared at 493 nm through PL spectral analysis. The second harmonic generation (SHG) efficiency of the title crystal has been measured, which indicates that DADMQ has 3.64 times greater than KDP crystal.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 48
·38382-38390
·
IF 3.84
Q. Zhong,Y. Y. Chen,S. L. Guan,Q. S. Fang,T. Chen,P. Müller-Buschbaum,J. P. Wang
The smart cleaning ability of cotton fabrics is realized by cross-linking thermo-responsive random copolymer to the cotton. Poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate), denoted as P(MEO2MA-co-EGMA), is synthesized from 2-(2-methoxyethoxy)ethoxyethyl methacrylate (MEO2MA) and ethylene glycol methacrylate (EGMA) with a molar ratio of 17 : 3. Its dilute aqueous solution (1 mg mL−1) presents a lower critical solution temperature (LCST) of 38 °C. Furthering increase the solution concentration, the LCST shifts towards lower temperature. By applying citric acid as a cross-linker, P(MEO2MA-co-EGMA) is successfully immobilized onto cotton fabrics. The obtained cotton fabrics also possess thermo-responsive property with a LCST at 37 °C. The smart cleaning ability is confirmed by single fiber cleaning experiments using a confocal microscope. It is observed that the cleaning ability of the cotton with cross-linked P(MEO2MA-co-EGMA) can be prominently enhanced at low temperature (below LCST). In addition, due to the low glass transition temperature of P(MEO2MA-co-EGMA) (−26 °C), the polymer is in a gel state at room temperature and will not negatively impact fabric softness. P(MEO2MA-co-EGMA) is a promising candidate for preparing textiles with smart cleaning ability and great fabric hand.
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高影响因子
CHEMISTRY & BIODIVERSITY
·
2025
·
IF 2.5
Ya-Shuai Kang,Hao-Wen Zhu,Xue Zhao,Hao Ma,Yu Yang,Rui Xu,Fu-Yao Luo,Er-Wei Li,Qian Luo,You-Zhi Zhang,Chang-Wei Li
A total of 46 endophytic fungi were isolated from Huperzia serrata and then cultured in a standard liquid medium and PDB medium. Cytotoxicity and antimicrobial activity assays revealed that seven crude extracts exhibited significant inhibitory effects on MCF-7 and SH-SY5Y cell lines; four crude extracts effectively inhibited the growth of Candida albicans , and 12 crude extracts demonstrated potent inhibition effects on Staphylococcus aureus . Strains displaying antimicrobial activity or potential for producing novel metabolites were selected for identification. In total, 14 strains representing 7 genera were identified, 5 of which had not been previously documented regarding their secondary metabolites. A fungus, Penicillium panissanguineum SZSS 4-2-2 was preliminarily selected for further chemical investigation. From the fermentation extract of P. panissanguineum SZSS 4-2-2, one new compound ( 1 ), one new natural product ( 2 ), and two known compounds ( 3 and 4 ) were isolated. The structures of these compounds were elucidated through spectral analysis and calculated nuclear magnetic resonance and electronic circular dichroism data. Compound 1 demonstrated a significantly stronger inhibitory effect on lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 macrophages, with an IC 50 value of 64.91 µM. By contrast, compounds 2 , 3 , and 4 exhibited only moderate inhibitory effects on NO production. Graphical In this study, a total of 46 endophytic fungi were isolated from H. serrata. Strains displaying antimicrobial activity or potential for producing novel metabolites were selected for identification. And, from the fermentation extract of one endophytic fungus, P. panissanguineum SZSS 4-2-2, one new compound (1), one new natural product (2), and two known compounds (3 and 4) were isolated.
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高影响因子
E-POLYMERS
·
2024
·Vol. 24
·期 1
·
IF 3.2
Yangyi Chen,Tong Su,Shihang Zhou,Chendi Xie,Huan Qi,Zaisheng Cai,Liqun Chen
The structure and transition behavior of crosslinked thermo-responsive poly(2-(2-methoxyethoxy) ethylmethacrylate- co -(ethyleneglycol) methacrylate) (P(MEO 2 MA- co -EGMA 360 )) gel film on a flat cellulosic-based substrate were investigated. The regenerated cellulose (RC) film was prepared by spin-coating with trimethylsilyl cellulose (TMSC), followed by etching with hydrochloric acid vapor on a treated silicon wafer, then crosslinked polymer gel film was obtained by spin-coating, drying, and baking with a pre-crosslinked solution containing polymers. Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer, and atomic force microscopy results show that a RC film with a thickness of 25 nm is generated in the upper layer of TMSC film on the silicon wafer. The cross-linking induces closer arrangement and hinders the extension of chain segments, leading to less prominent phase transition behaviors of polymer gel films. By quartz crystal microbalance measurement and 3D microscopes, a phase transition hysteresis is discovered, the hydrated and loose structure of crosslinked polymer gel film switches to dehydrated and compact structure in initial heating process, which subsequently recovers during the following cooling process. However, the degrees of rehydration and flexibility of film could not reach the initial value because of the insufficient transition time and steric hindrance caused by crosslinking.
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高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Jing-jing Zhang,Zong-cai Tu,Hui Wang,Yue-ming Hu,Peng-cheng Du,Yi-peng Yang
In this work, the mechanism of the effect of lipid oxidation on the IgG/IgE binding ability of ovalbumin (OVA) was investigated via the peroxyl radicals produced by 2, 2′-azobis (2-amidinopropane) dihydrochloride to simulate lipid oxidation. Results showed that the structure of OVA unfolded partially with an increase in oxidation degree, leading to the exposure of the allergenic epitopes and increasing the IgG/IgE binding ability of OVA. Nine oxidation sites were found on the α-helix, and these sites may unwind the α-helix and expose the allergenic epitopes on the OVA surface, leading to antibody recognition and combination. Consequently, the IgG/IgE binding ability of OVA was increased. In conclusion, the allergenic capacity of OVA can be promoted by modifying peroxyl radical oxidation in processing egg products.
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高影响因子
危险品化学品经营许可证（带存储）