CRYSTAL GROWTH & DESIGN
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2020
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IF 4.089
H. Liu,X. Yang,S. Cao,F. Yu,S. Long,J. Chen,M. Zhang,S. Parkin,T. Li,Z. Yang
A series of N-phenyl-2-hydroxynicotinanilides (PHNAs) have been synthesized, and their crystal structures have been investigated. The identity of these compounds is revealed to be the tautomer of PHNAs, i.e., 2-oxo-1,2-dihydropyridine-3-carboxylic acid phenylamides, compounds with both amide and lactam functionalities. Among these compounds, those with no or negligible steric hindrance take a near planar conformation and form lactam–lactam dimers, not the widely observed amide NH···O═C hydrogen bond chains, while those with steric hindrance take a twisted conformation and form an amide NH···O═C (lactam) hydrogen bond. A succinct theoretic study combining conformational analysis and molecular electrostatic potential surfaces (MEPS) survey provided a reasonable explanation of the formation of these two different hydrogen bond motifs.
研究领域:
化学
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晶体学
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
MONATSHEFTE FUR CHEMIE
·
2023
·Vol. 155
·期 1
·99-104
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IF 1.8
Dong Wenwen,Gong Tengfei,Liu Chaoyang,Lin Jia,Jia Qiang,Chu Changhu
Apixaban is a highly potent, selective, and efficacious inhibitor of blood coagulation factor Xa. A practical and efficient process has been developed for the preparation of the key intermediate of apixaban. Starting from inexpensive 4-chloronitrobenzene and piperidine, an eight-step procedure for the intermediate has been developed. In this case, sodium chlorite is used twice to oxidize the piperidine cycle to the corresponding lactam under a CO 2 atmosphere, resulting in the construction of two lactams. Furthermore, most of these reactions are highly efficient and practical as they occur under mild conditions. Most of the intermediates can be obtained through simple slurry or recrystallization, and column chromatography purification is not necessary. Graphical abstract
研究领域:
药物化学
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有机合成
✓ 已验证
DOI
高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
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2025
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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.
研究领域:
生物化学
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酶工程
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制药工业
✓ 已验证
DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
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2021
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IF 4.076
Yunping Zhoujin,Xing Yang,Mingtao Zhang,Ju Guo,Sean Parkin,Tonglei Li,Faquan Yu,Sihui Long
A lactam–lactam dimer (LLD) and lactam NH···O═C (amide) catemer (LAC) are two competing motifs in N-phenyl-2-hydroxynicotinanilides (PHNAs). Steric effects play an important role in determining the outcome of this competition, and in general, PHNAs with no or negligible steric hindrance take on a near-planar conformation and form LLDs, rather than the widely observed amide NH···O═C hydrogen-bond chains. Conversely, those with significant steric hindrance are forced to take on a twisted conformation and form a lactam NH···O═C (amide) hydrogen bond. Nevertheless, steric factors are not the only criteria, as an LLD and an LAC have been observed in the two polymorphs (1-I and 1-II) of 2-hydroxy-N-m-tolyl-nicotinamide (namely 2-oxo-1,2-dihydropyridine-3-carboxylic acid m-tolylamide, compound 1), although the molecules in both forms have a nearly identical conformation, in contrast to five other newly synthesized PHNAs (2–6), whose crystal structures are sustained on the LLD. Thus, synthon polymorphism is possible in conformationally planar PHNAs. Theoretical studies were performed to provide an explanation for this observation. The lattice energies of the two forms of 1 showed only an insignificant difference. A Hirshfeld analysis revealed that the loss of stability due to less hydrogen bonding in 1-II is compensated by the participation of π–π stacking. Other than the commonly observed LLD in the crystals, π–π stacking provides a significant stabilization for each crystal, with its particular effects being dependent on the substitution pattern of the compound. A noncovalent interaction (NCI) analysis further provided a visual demonstration of the important intermolecular interactions. Potentially the other planar compounds could behave in a similar manner.
研究领域:
晶体学
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理论化学
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材料科学
✓ 已验证
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 195
·期 2
·1216-1230
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IF 3.094
Cheng Qiaojuan,Chi Xinyu,Liang Yingchao,Li Wanxin,Sun Jiaxin,Tao Jin,Wang Zhi
Metal–organic frameworks (MOFs) can be used as the immobilization carriers to protect the physicochemical properties of enzymes and improve their catalytic performance. Herein, we report an in situ co-precipitation method to immobilize lipase from Candida sp. 99–125 in Cu-BTC MOF (BTC = 1, 3, 5-benzene tricarboxylic acid, H 3 BTC). Characterizations of the immobilized lipase (lipase@Cu-BTC) have confirmed the entrapment of lipase molecules in Cu-BTC MOF. The immobilized lipase has been successfully applied for resolving N- hydroxymethyl vince lactam ( N -HMVL) and its catalytic activity is five times that of native enzyme. More importantly, we found that Cu-BTC MOF can afford powerful protection for enzyme in nearly dry organic solvent and endow the immobilized lipase with excellent reusability and storage stability. Our present study may widen the application of immobilized enzyme with MOF as the immobilized carrier. Graphical Abstract
研究领域:
生物化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Gaopan Liu,Tianpeng Jiao,Yong Cheng,Ke Zhou,Yue Zou,Mingsheng Wang,Yong Yang,Jianming Zheng
A silicon-based anode is being developed for industrial application in lithium-ion batteries (LIBs) because of its extremely high theoretical specific capacity. However, the large volume variation during de/lithiation and poor interfacial stability issues cause rapid capacity decay, hindering its practical application. Herein, from the interfacial stabilization point of view, a lactam-based electrolyte additive, namely, N-acetylcaprolactam (donated as NACA), is explored to construct a flexible, robust, and protecting solid electrode interphase (SEI) on the SiOx/C electrode surface. On one hand, due to a stronger complexation with PF5/HF/H2O, NACA functions well in stabilizing the LiPF6 salt, thereby mitigating the corrosion of HF toward the SiOx/C electrode. On the other hand, the NACA-derived interphase could be well adapted to the huge volume change of the silicon electrode. As a consequence, the Li||SiOx/C battery with 2% NACA shows an increase in capacity retention by 15.6% at 30 °C and by 20.8% at 45 °C at 0.5C compared to the baseline. Meanwhile, the cycling performance of the NCM90 cathode is also improved with the NACA additive. Our work provides valuable understanding for seeking more effective amide-based additives for a silicon-based electrode and for the development of functional electrolytes for high-energy-density LIBs.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Fuyang Gu,Xiaoyan Wang,Jinmei Du,Yang Jiang,Dagang Miao,Yanmei Qu,Dongyan Shao,Guowei Xiao,Changhai Xu
Cationic bleaching activators can effectively achieve low-temperature bleaching in hydrogen peroxide system, but at the same time, self-hydrolysis reaction will occur to affect the low-temperature bleaching effect, and the complex hydrolysis pathways of cationic bleaching activators are still elusive. In this paper, the hydrolysis reaction pathways, mechanisms, rates and kinetics of cationic bleaching activators N-[4-(triethylaminomethyl)benzoyl]lactam chlorides (TBLCs) with different lactam leaving groups were investigated in depth by liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC). Specifically, we characterized the hydrolysis products by LC-MS and further quantified the hydrolysis products using HPLC, demonstrating that the hydrolysis can take place via two pathways, generating chain-breaking products and ring-opening products, and that both react at different rates depending on the different lactam leaving groups. Notably, the quantitative results showed that the chain-breaking products were always larger than the ring-opening products, and the chain-breaking products were ineffective for bleaching, which was the main reason for the decrease in the bleaching performance of TBLCs. The mechanism of hydrolysis is discussed and the reaction rate was determined to follow first-order kinetics using HPLC. We have successfully delineated the complete transformation pathway of the hydrolysis reaction using this method, providing valuable information for the future preparation of novel bleaching activators and the reduction of this reaction.
研究领域:
化学工程
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）