MOLECULES
·
2018
·Vol. 23
·期 9
·2234
·
IF 3.098
Qingqiang Tian,Zongjie Gan,Xuetong Wang,Dan Li,Wen Luo,Huajun Wang,Zeshu Dai,Jianyong Yuan
A highly efficient and convenient protocol of imidazolium chloride (30 mol %) catalyzed amidation of amines with moderate to excellent yields was reported. The protocol shows broad substrate scope for aromatic, aliphatic, and heterocyclic primary amines.Keywords:imidazolium chloride;catalyst;primary amines;transamidation
研究领域:
有机化学
·
催化反应
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DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2015
·
IF 2.837
Kai Yang,Shan-Shan Guo,Zhu-Feng Geng,Chun-Xue You,Wen-Juan Zhang,Yin-Ping Li,Cheng-Fang Wang,Shu-Shan Du,Zhi-Wei Deng
Five new sulphur-containing amides ( 2 , 5 – 8 ) and three known analogue compounds ( 1 , 3 – 4 ) were isolated from the leaves of Glycosmis lucida which were collected in Yunnan province, China. Their structures were elucidated with NMR spectroscopy and mass spectrometry. The compounds were identified as N -( p -hydroxyphenethyl)-3-(methylsulfonyl)-propenamide ( 1 ), N -[2-(4- hydroxyphenyl)-ethyl]-3-methanesulfonyl- N -methyl-propionamide ( 2 ), methylgerambullin ( 3 ), methylisogerambullone ( 4 ), methylgerambullindiol ( 5 ), N -{2-[4-(6,7-hydroxy-3,7-dimethyl-oct- 2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl- N -methyl-acrylamide ( 6 ), N -{2-[4-(6,7-dihydroxy- 3,7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfonyl- N -methyl-propionamide ( 7 ), ( E )- N -{2-[4-(6-hydroxy-7-dimethyl-oct-2-enyloxy)-phenyl]-ethyl}-3-methanesulfinyl- N -methyl- acrylamide ( 8 ). Feeding deterrent activities of these surphur-containing derivatives against Tribolium castaneum were assayed for the first time. Compound 2 , 3 , 6 possessed significant feeding deterrent activities against T. castaneum adults (EC 50 = 311.6, 244.9 and 108.3 ppm, respectively). These results demonstrated that some sulphur-containing amides are promising candidates as insect antifeedant agents.
研究领域:
植物化学
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昆虫学
·
天然产物研究
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DOI
高影响因子
ChemistryOpen
·
2020
·Vol. 9
·期 10
·996-1000
·
IF 2.37
Fangjun He,Rumeng Qu,Jie Su,Muyao Du,Junqiang Liu,Yiping Chen,Bo Wang
Graphical Solving the puzzle : The role of the amine in direct amidation of aromatic ketones has been investigated. Amines act as both the reactant and catalyst, as such the excess amount (two or more equivalents) of amines are required to afford reasonable conversions/yields in the classical amidation. The direct amidation of aromatic ketones has been achieved at mild reaction conditions. In the classical amidation between aromatic ketones and amines, 2.0 equivalents of amines are necessarily required to gain satisfying yields. The specific role of the amine in the direct amidation already puzzled us for a long time. In this work, we disclosed that the amine acts as both reactant and catalyst. Specifically, the determination of reaction intermediates revealed the full mechanism, based on which, the introduction of one equivalent base in the amidation is showcased here that a high yield (∼95 %) can be afforded using only 1.1 equiv. of amine.
研究领域:
有机化学
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催化化学
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DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2024
·
IF 11
Jirong Wang,Chengying Zhao,Yuying Chen,Fengzhang Wang,Liping Feng,Yanqi Wang,Chunhong Li,Yuming Bao,Jinkai Zheng
For many applications as a food additive, the emulsifying properties of commercial pectin are usually need to be upgraded to obtain better stabilization properties, to extend the shelf-life of food products. In this study, a novel method was developed in which pectin was activated by 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholin-4-ium chloride (MMTM) to obtain pectins amidated with different amino acids and then the structural characteristics, emulsifying properties, and structure–property relationships of the resulting modified pectins were systematically explored. MMTM efficiently activated the amidation of pectin with different amino acids. Pectin amidated with alkaline amino acids had the highest degree of amidation (DA), ranging from 13.5% to 24.8%, followed by amidation with neutral (6–11.9%) and acidic (4.5–6.4%) amino acids. The high DA and larger number of hydrophobic groups of pectins amidated with lysine, arginine, histidine, methionine, or phenylalanine resulted in emulsions with a smaller particle size (610.1–907.0 nm) and greater stability than obtained with the original pectin. The thicker adsorption layer resulting from the high-molecular-weight cysteine-amidated pectin accounted for the high stability of the emulsion. These results provide the basis for the development of novel methods for modifying pectin, based on amidation with amino acids, to significantly improve emulsification.
研究领域:
食品科学
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化学
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材料科学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2024
·
IF 8.2
Yizhou Feng,Daohui Lin,Kun Yang,Wenhao Wu
Knowledge of antibiotic desorption from high-temperature biochar is essential for assessing their environmental risks, and for the successful application of biochar to remove antibiotics. In previous studies, irreversible pore deformation, formation of charge-assisted hydrogen bonds or amide bonds were individually proposed to explain the desorption hysteresis of antibiotics on biochars, leading to a debate on hysteresis mechanism. In this study, desorption of sulfamethoxazole (SMX), ciprofloxacin (CFX) and tetracycline (TET) on a wood chip biochar produced at 700 °C (WBC700) and its oxidized product (O-WBC700) was investigated to explore the underlying hysteresis mechanism. Significant desorption hysteresis was observed for SMX, CFX and TET on WBC700 and O-WBC700. Hysteresis index (HI) of each antibiotic was higher on O-WBC700 with more oxygen-containing groups than WBC700, and was higher at lower equilibrium concentration. HI of antibiotics on WBC700 (or O-WBC700) increased in the order of SMX < CFX < TET. The calculated adsorption enthalpy of each antibiotic on WBC700 was positive, indicating an endothermic process. These phenomena together with FTIR, XPS spectra confirmed that the desorption hysteresis mechanism of antibiotics on high-temperature biochar is the formation of amide bonds by amidation reaction, but not the pore deformation or the hydrogen bond. Moreover, antibiotic can form amide bonds with WBC700 only if the amine group with p K a > 4.0, and the HI values were positively correlated with their p K a values. Amine group of antibiotics with higher p K a value show more nucleophilicity and could form stronger amide bonds with carboxyl group of biochar. The obtained results could help to solve the debate on desorption hysteresis mechanism of antibiotics on high-temperature biochars, and provide a new insight into the role of amine groups and amidation reaction on the hysteresis.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PAPERS
·
2014
·Vol. 68
·期 10
·1408-1414
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IF 1.193
Cao Meng,Hu Hua-You,Zhao Hu-Cheng,Zhang Xi-Quan,Gu Hong-Mei,Yang Ling,Cai Jin,Wang Peng,Hu Bing,Ji Min
In the current study a facile synthetic route for preparing antineoplastic drug GDC-0449 is investigated. Starting with pyridine-1-oxide and 1-iodo-3-nitrobenzene, the intermediate product 2-(2-chloro-5-nitrophenyl) pyridine was prepared by cross-coupling, deoxidation and halogenation. The final compound was then synthesised by reduction of the nitro group followed by amidation. This synthetic route avoids the use of unstable organometallic or organic boride compounds; it employs relatively inexpensive and bench-stable reagents, involves readily controllable reaction conditions, and achieves a relatively high yield.
研究领域:
药物化学
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有机合成
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肿瘤学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2023
·Vol. 89
·期 7
·
IF 4.4
Ping Lu,Juan Xue,Xi Chen,Xuemeng Ji
Cronobacter sakazakii is a Gram-negative bacterium that causes infections in individuals of all ages, with neonates being the most vulnerable group. The objective of this study was to explore the function of the dnaK gene in C. sakazakii and to elucidate the impact of alterations in the protein composition regulated by dnaK on virulence and stress adaptation. Our research demonstrates the critical role of the dnaK gene in various key virulence factors, including adhesion, invasion, and acid resistance in C. sakazakii. Through the use of proteomic analysis, we discovered that deletion of the dnaK gene in C. sakazakii leads to an upregulation of protein abundance and increased levels of deamidated posttranscriptional modifications, suggesting that DnaK may play a role in maintaining proper protein activity by reducing protein deamidation in bacteria. These findings indicate that DnaK-mediated protein deamidation may be a novel mechanism for virulence and stress adaptation in C. sakazakii. These findings suggest that targeting DnaK could be a promising strategy for developing drugs to treat C. sakazakii infections.IMPORTANCE Cronobacter sakazakii can cause disease in individuals of all ages, with infections in premature infants being particularly deadly and resulting in bacterial meningitis and sepsis with a high mortality rate. Our study demonstrates that dnaK in Cronobacter sakazakii plays a critical role in virulence, adhesion, invasion, and acid resistance. Using proteomic analysis to compare protein changes in response to dnaK knockout, we found that dnaK knockout significantly upregulates the abundance of some proteins but also results in the deamidation of many proteins. Our research has identified a connection between molecular chaperones and protein deamidation, which suggests a potential future drug development strategy of targeting DnaK as a drug target.
研究领域:
微生物学
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分子生物学
·
医学
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Jirong Wang,Chengying Zhao,Shaojie Zhao,Xingmiao Lu,Mengyu Ma,Jinkai Zheng
The amidation of pectin by amino acids has been widely applied due to its safety and excellent gelling properties. This study systematically examined the effects of pH on the gelling properties of lysine-amidated pectin during amidation and gelation . Pectin was amidated over the range of pH 4–10, and the amidated pectin obtained at pH 10 showed the highest degree of amidation (DA, 27.0 %) due to the de-esterification, electrostatic attraction, and the stretching state of pectin. Moreover, it also exhibited the best gelling properties due to its greater numbers of calcium-binding regions (carboxyl groups) and hydrogen bond donors (amide groups). During gelation, the gel strength of CP (Lys 10) at pH 3–10 first increased and then decreased, with the highest gel strength at pH 8, which was due to the deprotonation of carboxyl groups, protonation of amino groups, and β-elimination. These results show that pH plays a key role in both amidation and gelation, with distinct mechanisms, and would provide a basis for the preparation of amidated pectins with excellent gelling properties. This will facilitate their application in the food industry.
研究领域:
食品科学
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化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Rui Zhu,Yaxin Wang,Minshu Cui
A strategy for the photocatalytic conversion of α-amino acids into corresponding amides was developed. A series of carbon nitride samples were prepared as the catalyst. Various characterizations of the catalyst indicated that effective photocatalytic activity and low recombination efficiency of photo-generated carriers were significant for the high activity of the catalyst. Reaction conditions for the photocatalytic decarboxylation of α-amino acids were optimized, alongside an investigation into the potential mechanism through controlled experiments and DFT computations. Mechanism studies unveiled that photo-generated electrons activated O 2 to reactive oxygen species, while photo-generated holes induced the decarboxylation reactions by activating the carboxylic acid groups, generating carbon radicals that ultimately lead to the formation of corresponding amides under the influence of reactive oxygen species. Moreover, the photocatalytic decarboxylation of different alpha amino acids was also discussed, providing new strategies for the formation of amides and lactams.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
Science Advances
·
2021
·Vol. 7
·期 46
·
IF 14.143
Chengtao Xu,Biao Ma,Zhongli Gao,Xing Dong,Chao Zhao,Hong Liu
DNA has been considered as a compelling candidate for digital data storage due to advantages such as high coding density, long retention time, and low energy consumption. Despite many works reported, the development of a DNA-based database of full integration, high efficiency, and practical applicability is still challenging. In this work, we report the synthesis and sequencing of DNA on a single electrode with scalability for an integrated DNA-based data storage system. The synthesis of DNA is based on phosphoramidite chemistry and electrochemical deprotection. The sequencing relies on charge redistribution originated from polymerase-catalyzed primer extension, leading to a measurable current spike. By regeneration of the electrode after sequencing, repeated sequencing can be achieved to improve the accuracy. A SlipChip device is developed to simplify the liquid introduction involved in DNA synthesis and sequencing. As the proof-of-concept experiment, text information is stored in the system and then accurately retrieved.
研究领域:
生物技术
·
分子生物学
·
数据科学
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DOI
高影响因子
Journal of Flow Chemistry
·
2021
·Vol. 11
·期 4
·855-866
·
IF 2.786
Xu Qilin,Zhang Shuqing,Zhao Jinyang,Wang Zhikuo,Liu Linchang,Zhou Pengcheng,Yu Zhiqun,Su Weike
Here we developed a continuous flow microreactor system to synthesis N -benzoylpiperazine, which is an important intermediate of novel nootropic Sunifiram. And the kinetics of the condensation amidation of piperazine and benzoic acid using HATU as coupling reagent was revealed in microreactor. A kinetic model was established, all the reactions kinetics parameters, including the reaction order of each reactant, rate constants, pre-exponential factors and activation energies were acquired. With this model the selectivity vs. reaction temperature/molar flow ratio were obtained to help understand this kind of reaction and further optimize operating conditions. Under the condition of using equivalent piperazine, 95.6% of selectivity and 91.2% of yield were obtained in microreactor with 50 s. To further expand the scope of carboxylic acid, cyclopropanecarboxylic acid was tried as acylating agent, and 92.8% of selectivity and 86.1% of yield were obtained in microreactor.
研究领域:
有机化学
·
药物合成
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产品关联
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Chao Ma,Lijun Qian,Zhenghong Guo,Juan Li
A phosphonate flame retardant containing cyano group (CPDPO) was synthesized by using diphenylphosphinyl chloride and 4-cyanophenol and used to modify the flame retardancy epoxy (EP). The curing process, flame retardant performance and mechanism of EP/CPDPO were investigated. The cyano is a strong electron-withdrawing group which makes some CPDPO to react with EP via transesterification , thus about 17% diphenyl phosphine oxide (DPO) and 4-cyanophenol group will be grafted onto the chain of EP. Therefore CPDPO plays a self-compatibilization role in the system. The EP with 6 wt% CPDPO achieves the UL-94 V-0 rating and a LOI value of 36.6%. The peak of heat release rate and total heat release of EP with 6 wt% CPDPO are decreased by 47% and 24% compared with EP, respectively. The DPO grafted on the EP network tends to work in the condensed phase, while the free CPDPO is easy to work in the gas phase. The latter is far more than the former. Therefore, the effect of gas phase is obviously greater than that of condensed phase, which matches the structure of EP which has good charring ability itself. Moreover, the EP/CPDPO has better mechanical properties than that of EP and transparency equivalent to itself. This work suggests that the phosphonate containing strong electron-withdrawing group not only has self-compatibilization effect, but also regulates the properties and flame retardant mechanism.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）