JOURNAL OF CHEMICAL EDUCATION
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2024
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IF 2.5
Huifa Han,Yali Qin,Fan Wang,Ning Ding,Fang Fang,Lihong Hu,Hongming Jin,Yinan Zhang
Electrophilic aromatic substitution (SEAr) and nucleophilic aromatic substitution (SNAr) reactions are among the most valuable reactions in the conversion of aromatic rings. While these reactions are typically covered in separate experiments in undergraduate organic courses, a continuous experimental setup elucidating both SEAr and SNAr processes remains unexplored in the literature for undergraduate laboratories. We herein described a two-step experimental design to cascade the SEAr and SNAr reactions, aiding students in better understanding the similarities and differences of these conversions as well as introducing the concept of umpolung. The experiment also reinforces students’ proficiency in fundamental organic synthesis techniques and workup procedures, such as TLC analysis, chromatography purification, recrystallization, and handling LRMS and NMR.
研究领域:
有机化学
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化学教育
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产品关联
DOI
高影响因子
ACS Omega
·
2020
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IF 2.87
Baojie Liu,Chengrong Qin,Fuqiang Zhang,Shuo Wang,Chen Liang,Shuangxi Nie,Shuangfei Wang,Shuangquan Yao
In fact, the chemical reaction rate of traditional chlorine dioxide bleaching of pulp is too fast to observe the intermediate process. The mechanism behind the reaction of 4-hydroxy-3-methoxyacetophenone (APO), a phenolic lignin model compound, with high concentrations of chlorine dioxide was investigated. Individual solutions of each compound and a mixture of the two were analyzed by UV–vis spectrophotometry, and an absorbance band at 260 nm was observed for the stable benzoquinone intermediates at room temperature. Free chlorine dioxide displayed an absorbance at 360 nm and changes in this absorbance were studied with different APO concentrations. A fixed molar ratio of 1:3 was obtained between APO and chlorine dioxide consumption. The intermediate absorbance demonstrated a linear relationship with the APO concentration. The reaction path between APO and chlorine dioxide at high concentrations was speculated, and it was observed that the activity of C1, C2, C3, C5, and C6 on the APO benzene ring was enhanced when high concentrations of chlorine dioxide were present. From these results, a new method for efficient and clean chlorine dioxide bleaching can be developed.
研究领域:
化学工程
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环境科学
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产品关联
DOI
PubMed
高影响因子
ANALYST
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2021
·Vol. 146
·期 12
·4080-4086
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IF 4.616
Hao Gu,Kang Ma,Weiqian Zhao,Lirong Qiu,Wei Xu
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been widely applied for the analysis of large biomolecules. The emergence of inorganic material substrates and new organic matrices extends the use of MALDI MS for small molecule analyses. However, there are usually preferred matrices for different types of analytes. Here, an organic compound, 4-hydroxy-3-nitrobenzonitrile, was found to be a general purpose matrix for the analyses of small organic, peptide and protein molecules. In particular, 4-hydroxy-3-nitrobenzonitrile has a strong UV absorption property, and it provides a clean background in the low mass range. Its analytical performances as a UV-laser matrix were demonstrated for different types of analytes, including organic drugs, peptides, proteins, mouse brain tissue and bacteria. Compared with commercial matrices, this new matrix has better performances when analyzing small molecules, such as drugs, peptides and lipids, while it has similar performances when analyzing proteins.
研究领域:
分析化学
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质谱分析
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生物分子分析
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产品关联
DOI
PubMed
高影响因子
Surfaces and Interfaces
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2023
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IF 6.2
Hao Yang,Yi Liu,Hidetoshi Saitoh,Hao Chen,Hua Li
Biofouling is a stepwise accumulation process involving participation of various molecules and marine organisms. To tackle this complex threat, development of efficient long-term antifouling coatings yet keeps elusive. Here we report a newly constructed coating with both antifouling activity and low surface energy. The special surface structure formed by silica spheres and fluorosilanes offers the coating superhydrophobicity. Capsaicin-mimicking N-(4-hydroxy-3-methoxy-benzyl)-acrylamide (HMBA) powder is synthesized via the Friedel-Crafts reaction and is used as the antifoulant additives in the coating. By the synergistic effect of surface superhydrophobicity and the dispersed antifoulant, the multilayered HMBA-silica coating effectively inhibits the adhesion of alginate, bovine serum albumin and Chlorella , their adhesion rate on the HS-3 coating is 11.9 %, 8.7 % and 3.3 % respectively. The HS-3 coating kills 96.6 % gram-negative bacteria E. coli and 99.9 % gram-positive bacteria S. aureus. Furthermore, the HMBA-silica coating significantly mitigates by its superhydrophobicity the corrosion of artificial seawater, its corrosion current density has decreased by 4 orders of magnitude compared to bare 316 L plate. In a 90 days real seawater immersion experiment, the coating shows excellent anti-fouling and anti-corrosion properties. The fabrication route of the HMBA-silica coating using the synthesized broad-spectrum antifoulant HMBA and hydrophobic silica would give insight into developing new antifouling materials for marine applications.
研究领域:
材料科学
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海洋生物学
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化学
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表面工程
✓ 已验证
产品关联
DOI
高影响因子
CURRENT ISSUES IN MOLECULAR BIOLOGY
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2024
·Vol. 46
·期 4
·3694-3712
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IF 2.8
Kai Li,Yuan Wang,Xiao Guo,Bo Wang
Establishing a multi-enzyme synergistic lignocellulosic biodegradation system using lytic polysaccharide monooxygenase (LPMO) and polyphenol oxidases is vital for efficiently utilizing plant biomass waste, ultimately benefiting the carbon cycle and promoting environmental protection. Single-residue mutations of LPMO can improve the efficiency of lignocellulosic biomass degradation. However, the activity of mutant-type LPMO in relation to lignin-diverted reducing agents has not been sufficiently explored. In this study, laccase and tyrosinase were initially investigated and their optimal conditions and impressive thermal stability were revealed, indicating their potential synergistic abilities with LPMO in lignocellulose biodegradation. When utilizing gallic acid as a reducing agent, the activities of LPMOs were increased by over 10%, which was particularly evident in mutant-type LPMOs after the addition of polyphenol oxidases. In particular, the combination of tyrosinase with either 4-hydroxy-3-methoxyphenylacetone orp-coumaric acid was shown to enhance the efficacy of LPMOs. Furthermore, the highest activity levels of wild-type LPMOs were observed with the addition of laccase and 3-methylcatechol. The similarities between wild and mutant LPMOs regarding their activities in lignin-diverted phenolic compounds and reducing agents are almost identical, suggesting that the single-residue mutation of LPMO does not have a detrimental effect on its performance. Above all, this study indicates that understanding the performance of both wild and mutant types of LPMOs in the presence of polyphenol oxidases and various reducing agents constitutes a key link in the industrialization of the multi-enzyme degradation of lignocellulose.
研究领域:
生物技术
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生物化学
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环境科学
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酶学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2024
·
IF 3.1
Yufang Huang,Xikang Ren,Yonghui Li,Junqing Zhang,Na Wei,Hailong Li,Yinfeng Tan
The Liangfu formula, as described in 'Liangfang Jiye', is well-known for its efficacy in treating stomach pain, abdominal pain, and dysmenorrhea. This research aimed to investigate the pharmacokinetics and tissue distribution of 5-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-heptanone (DPHA), Galangin, Kaempferide, 5-Hydroxy-1,7-diphenyl-3-heptanone (DPHC), α-Cyperone, and Nootkatone in vivo using an LC-MS/MS method. The method successfully separated the six active components and internal standards (Chrysin and Yakuchinone-A) on an XB-C18 column with a mobile phase of 0.2 ‰ formic acid water-acetonitrile. It demonstrated good linearity with a correlation coefficient (r 2 ) ≥ 0.9911 and a lower limit of quantification (LLOQ) of 5–80 ng/mL for the different components. Precision, accuracy, matrix effects, and recovery rates were within acceptable ranges. Pharmacokinetic analysis revealed significant differences in parameters between primary dysmenorrhea (PD) and normal rats (especially AUC, T max, and CL z /F). Tissue distribution showed that the six active components of the herbal pair Alpinia officinarum Hance- Cyperus rotundus L. (HPAC) extract was primarily distributed in the liver, lung, and kidney. This study offers valuable insights into the potential mechanisms of action and drug development for treating PD.
研究领域:
药理学
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中医
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分析化学
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药物动力学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2023
·
IF 5.9
Hua-Bin Yuan,Xue Lei,Jin Cheng,Tieling Xing,Guoqiang Chen
Polyphenols have been utilized to connect hydrophobic modifiers with certain substrates because of their adhesive properties and multiple active groups in their structure. Nevertheless, research is scarce regarding using polyphenols to enhance the superhydrophobic properties of polyamide . In this study, a plant-derived phenolic compound , p-coumaric acid (pCA), was chelated with Fe 3+ and deposited on the polyamide 66 (PA66) surface to increase its roughness. Subsequently, octadecanethiol was grafted onto pCA using a thiol-ene click chemistry reaction to create a superhydrophobic modified PA66 fabric (pCA-Fe-SH-PA66) with a static water contact angle (CA) of 154.4° and a sliding angle (SA) of 2°. The resulting pCA-Fe-SH-PA66 demonstrated excellent capabilities in self-cleaning, UV-blocking, photothermal conversion, and oil-water separation. Furthermore, pCA-Fe-SH-PA66 exhibited remarkable antibacterial ability, displaying inhibitory rates of 97.00% against E. coli and 96.15% against S. aureus , respectively. Additionally, it demonstrated noteworthy stability in a series of tests, encompassing 225 min of washing, 1000 cycles of abrasion, 48 h of UV light aging, 48 h of acid/base solution, seawater, and organic reagents immersion. Furthermore, it was demonstrated that three additional plant-derived phenolic compounds, namely 3-hydroxycinnamic acid (HA), polyatin (PD), and 4-hydroxy-3,5-dimethoxycinnamic acid (HDA), can also be effectively utilized for the multifunctional modification of PA66 fabric. The proposed modification method is mild, fast, and simple, offering a novel approach to the multifunctional modification of synthetic materials. The modified PA66 fabric holds potential in applications such as oily wastewater treatment , outdoor sportswear, tents, and other fields.
研究领域:
材料科学
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化学工程
·
纺织科学
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环境科学
·
生物技术
✓ 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）