ACS Omega
·
2020
·
IF 2.87
Yan Ji,Xiaoliang Yang,Zhi Ji,Linhui Zhu,Nana Ma,Dejun Chen,Xianbin Jia,Junming Tang,Yilin Cao
The infrared spectrum (IR) characteristic peaks of amide I, amide II, and amide III bands are marked as amide or peptide characteristic peaks. Through the nuclear magnetic resonance study, N-methylacetamide has been determined to have six fine components, which include protonation, hydration, and hydroxy structures. Then the independent IR spectrum of every component in N-methylacetamide is calculated by using the density functional theory quantum chemistry method, and the contribution of each component to amide I, II, and III bands is analyzed. The results of this research can help to explain the formation of the amide infrared spectrum, which has positive significance in organic chemistry, analytical chemistry, and chemical biology.
研究领域:
有机化学
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分析化学
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化学生物学
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DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
·
2020
·
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
·
理论计算
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2024
·
IF 6.2
Rongfang Yang,Jiaxin Zhang,Xiumei Xing,Shiyuan Zhong,Wenxue Li,Lixian Wen,Yuwei Zhang,Hongwei Zhou,Shen Chen,Wen Chen,Yongmei Xiao,Liping Chen
Benzene exposure has been linked to various adverse health effects. However, the effective strategy for prevention or treatment of benzene-induced hematotoxicity remains unsolved. We previously administrated hepatocyte-specific deletion of Ppp2r1a gene (encoding PP2A Aα subunit) mice with benzene via inhalation for 28 days, and found homozygote (HO) mice exhibited alleviative hematotoxicity compared with wild type (WT) mice. Here, we integrate untargeted metabolomics and transcriptomics data to identify the key metabolic pathways and metabolites attenuating benzene-induced hematotoxicity. Metabolomics analysis revealed the perturbation of nicotinate and nicotinamide metabolism, as well as taurine and hypotaurine metabolism pathways, were implicated in regulating benzene-induced hematotoxicity. Meanwhile, transcriptome analysis showed that immune-, inflammation-, and metabolism-related pathways were obviously disturbed in WT mice groups upon benzene exposure, while sirtuin signaling pathway, associated with nicotinate and nicotinamide metabolism, was activated in HO mice groups. Notably, combined metabolomics and transcriptomics analysis further confirmed the involvement of nicotinate and nicotinamide metabolism, taurine and hypotaurine metabolism pathways in relieving benzene-induced hematotoxicity. Specific metabolites, including 1-methylnicotinamide (MNA), nicotinamide (NA), β-nicotinamide mononucleotides (NMN), and taurine were identified as the potential metabolites alleviating benzene-induced adverse effects. In vitro experiments demonstrated the protective effect of MNA and NA against 1,4-benzoquinone (1,4-BQ)-caused cytotoxicity in HL-60 cells. In vivo , MNA supplementation in drinking water could effectively restore the decline in white blood cell (WBC), lymphocyte (LYMPH), and reticulocyte (RET) counts, also mitigate oxidative damage and genotoxicity in response to benzene exposure. These observations highlight the potential of MNA supplementation as a strategy for preventing benzene-caused hematotoxicity.
研究领域:
毒理学
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代谢组学
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分子生物学
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DOI
PubMed
高影响因子
Polymer Chemistry
·
2022
·Vol. 14
·期 5
·573-586
·
IF 5.364
Xinjin Yan,Meng Wei,Xu Miao,Xiaoguang Qiao,Xiaomeng Zhang,Peng Fu,Xinchang Pang,Minying Liu,Qingxiang Zhao,Shuang Chen,Zhe Cui
Luminescence of non-conjugated polymers attracts much attention due to its importance in fundamental and applied research. At present, however, the research on nonconventional luminescent polymers (NLPs) in terms of both the structure regulation and emission mechanism seems to be still in its infancy. Herein, we report for the first time that PA1212, a representative engineering plastic with the longest saturated carbon chain among commercial polyamides, is an efficient NLP, which exhibits dual emission of blue fluorescence and persistent room-temperature green phosphorescence as well as high quantum yield (∼13%). Systematic photophysical characterization demonstrates the important role played by hydrogen-bonded amide groups in the emission, and the emission intensity shows a clear linear positive correlation with the amide clusters constructed from ordered hydrogen bonds in the crystalline region. Moreover, PA1212 in the α form with linearly extended hydrogen-bonded clusters exhibits longer emission wavelengths than in the γ form, owing to the narrower band gap between the valence band maximum and the conduction band minimum. Further variable temperature fluorescence studies reconfirm the amide cluster-triggered emission (CTE) mechanism of PA1212, and show the possibility of application of fluorescence spectra in the study of polyamide aggregation states. This work not only deepens the understanding of CTE, but also provides a new strategy to regulate the luminescence of polyamides, and meanwhile, highlights the application prospects of luminescent polyamides.
研究领域:
材料科学
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光物理学
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DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2021
·Vol. 43
·期 8
·1617-1624
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IF 2.461
Wang Liuzhu,Jiang Shuiqin,Sun Yangyang,Yang Zeyu,Chen Zhi,Wang Hualei,Wei Dongzhi
Objectives Catalytic promiscuity, or the ability to catalyze a secondary reaction, provides new opportunities for industrial biocatalysis by expanding the range of biocatalytic reactions. Some nitrilases converting nitriles to amides, referred to as the secondary activity, show great potential for amides production. And our goal was exploiting the amide-forming potential of nitrilases. Results In this study, we characterized and altered the secondary activity of nitrilase from Acidovorax facilis 72 W (Nit72W) towards different substrates. We increased the secondary activity of Nit72W towards 2-cyanopyridine by 196-fold and created activity toward benzonitrile and p-nitrophenylacetonitrile by modifying the active pocket. Surprisingly, the best mutant, W188M, completely converted 250 mM 2-cyanopyridine to more than 98% 2-picolinamide in 12 h with a specific activity of 90 U/mg and showed potential for industrial applications. Conclusions Nit72W was modified to increase its secondary activity for the amides production, especially 2-picolinamide.
研究领域:
生物化学
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工业生物技术
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Guangcun Qian,Deliang Zhu,Jiangnan Li,Yu Li,Hongyan Tang
In practical applications, Nanofiltration (NF) membranes are confronted with inevitable challenges, including the terrible fouling and the deterioration by chlorine, which hinders the wider application. In this study, 2-aminophenol-4-sulfonamide (APSA) was incorporated to form the polyamide-sulfonamide active layer, thus highly stable antifouling NF membranes with chlorine resistance were fabricated. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results showed APSA successfully grafted on the membrane surface. Scanning electron microscope (SEM) and atomic force microscope (AFM) images indicated a smooth membrane surface. Water contact angle of the PA-SA NF membranes declined to 19.7° compared with the PA NF membranes. Flux recovery rates (FRR) of bovine albumin (BSA), humic acid (HA), sodium alginate (SA) and oil/water emulsion were 96.4%, 96.8%, 96.0% and 94.6%, respectively. Besides, slight decline occurred to FRR value for BSA after three fouling cycles. No obvious decline of the rejection and water flux was observed on long-term stability. Notably, slight rejection rate decline and no obvious FRR value decline were observed after chlorination. Overall, the PA-SA NF membranes possessed highly stable antifouling property and chlorine resistance. It might be due to the fact that APSA including various hydrophilic groups grafted onto the active layer. N–H bonds of sulfonamide could act as a sacrificial unit against free chlorine. It is anticipated that this work could provide a facile strategy to develop NF membranes with highly stable antifouling property and chlorine resistance.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
Scientific Reports
·
2019
·Vol. 9
·期 1
·1-11
·
IF 4.011
Hu Chunhui,Zhao Shuxue,Li Kuiran,Yu Hao
A novel Alcaligenes sp. strain P156, which can utilize nicotinamide as its sole source of carbon, nitrogen and energy, was enriched and isolated from soil in a solid waste treatment plant. Aerobic growth and degradation with nicotinamide were characterized. Seven nicotinamide degradation-related genes were obtained by sequence alignment from the genome sequence of strain P156. Four genes, designated naaA , naaD , naaE and naaF , were cloned and heterologously expressed. Nicotinamide degradation is initiated by deamination to form nicotinic acid catalyzed by the nicotinamidase NaaA, which shares highest amino acid sequence identity (27.2%) with nicotinamidase from Arabidopsis thaliana . Nicotinic acid is converted to 6-hydroxynicotinic acid, which is further oxidized to 2,5-dihydroxypyridine (2,5-DHP). 2,5-DHP is then transformed to a ring-cleavage product, N -formylmaleamic acid, by an Fe 2+ dependent dioxygenase NaaD. N -formylmaleamic acid is transformed to fumaric acid through maleamic acid and maleic acid by NaaE and NaaF, respectively. To our knowledge, this is the first report of the complete microbial degradation of nicotinamide in bacteria. Nicotinamide is considered as a model compound for the study of microbial degradation of pyridinic compounds, and the nicotinamide degrading related genes in strain P156 were distributed differently from the reported similar gene clusters. Therefore, this study contribute to the knowledge on the degradation of pyridinic compounds.
研究领域:
微生物学
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环境科学
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基因组学
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2013
·Vol. 5
·期 20
·5615-5621
·
IF 1.855
Hongli Sun,Yiwei Wu
A new micellar electrokinetic capillary chromatography (MEKC) method combined with field-amplified sample injection (FASI) has been developed for the analysis of isonicotinamide and nicotinamide in whitening cosmetics and supplemented foodstuffs. Parameters affecting FASI preconcentration and MEKC separation were optimized systematically. Compared with direct MEKC, the sensitivity of FASI-MEKC was improved by 12.8- and 9.8-fold for isonicotinamide and nicotinamide, respectively. The detection limits (LODs) of isonicotinamide and nicotinamide were 0.051 μg mL−1 and 0.069 μg mL−1, respectively, with RSD (intraday) < 4.9% (n = 7, c = 0.5 μg mL−1) and RSD (interday) < 6.4% (n = 5, c = 0.5 μg mL−1). The proposed method was successfully applied in determination of isonicotinamide and nicotinamide in whitening cosmetics and supplemented foodstuffs with acceptable recoveries of 84.7–108.4%.
研究领域:
分析化学
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药物分析
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化妆品科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Huibing Chi,Bingjie Xia,Juan Shen,Xiaoyu Zhu,Zhaoxin Lu,Fengxia Lu,Ping Zhu
Type II L-asparaginase as a pivotal enzyme agent has been applied to treating for acute lymphoblastic leukemia (ALL) and efficient mitigation of acrylamide formed in fried and baked foods. However, low activity, narrow range of pH stability, as well as undesirable glutaminase activity hinder the applications of this enzyme. In our work, A novel type II L-asparaginase (CgASNase) from Corynebacterium glutamicum with molecular mass of about 35 kDa was chosen to express in E. coli . CgASNase shared only 27 % structural identity with the reported L-asparaginase from Helicobacter pylori . The purified CgASNase showed the highest specific activity of 1979.08 IU mg −1 to L-asparagine, compared with reported type II ASNases in the literature. CgASNase displayed superior stability at a wide pH range from 5.0 to 11.0, and retained about 76 % of its activity at 30 °C for 30 min. The kinetic parameters K m (Michaelis constant), k cat (turnover number), and k cat / K m (catalytic efficiency) values of 4.66 mM, 79,697.40 min −1 , and 17,102.45 mM −1 min −1 , respectively. More importantly, CgASNase exhibited strict substrate specificity towards L-asparagine, no detectable activity to l -glutamine. To explore its ability to catalyze L-asparagine, CgASNase was supplied in frying potato chips, which produced the fries with 84 % less acrylamide content compared with no supply. These findings suggest that CgASNase presents excellent properties for chemotherapy against diseases and great potential in the food processing industry.
研究领域:
生物化学
·
酶学
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食品科学
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肿瘤学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2014
·
IF 4.331
Yun Cai,Zhenhua Zhang,Shanshan Jiang,Miao Yu,Caihuan Huang,Ruixia Qiu,Yueyu Zou,Qirui Zhang,Shiyi Ou,Hua Zhou,Yong Wang,Weibing Bai,Yiqun Li
This research was aimed to investigate why chlorogenic acid, presents at high concentrations in some food raw material, influences acrylamide formation. In the asparagine/glucose Maillard reaction system (pH = 6.8), addition of chlorogenic acid significantly increased acrylamide formation and inhibited its elimination. In contrast, the quinone derivative of chlorogenic acid decreased acrylamide formation. Three mechanisms may be involved for increasing acrylamide formation by chlorogenic acid. Firstly, it increased the formation of HMF, which acts as a more efficient precursor than glucose to form acrylamide. Secondly, it decreased activation energy for conversion of 3-aminopropionamide (3-APA) to acrylamide (from 173.2 to 136.6 kJ/mol), and enhances deamination from 3-APA. And thirdly, it prevented attack of the produced acrylamide from free radicals by keeping high redox potential during the Maillard reaction.
研究领域:
食品科学
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化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 20
·12018-12029
·
IF 4.22
Chen Juan,Gong Caihong,Yang Ce,Yi Chunwang
The harsh synthesis conditions and lack of hard segments have long presented difficulties in the preparation of polyamide-based thermoplastic elastomers (TPAEs). In this work, a facile synthesis of TPAEs was developed using amide exchange. First, itaconic acid-polyoxypropylene diamine copolymer (IA-PPA) was synthesized by copolymerizing bio-based polyoxypropylene diamine (PPA D400) and itaconic acid (IA). The P2000 (IA-PPA with Mn ~ 2000) was then used as the soft segment of polyamide-6 based thermoplastic elastomers (PA6- b -P2000). Experimental results indicate that P2000 could directly initiate the ring-opening polymerization of caprolactam to form a prepolymer containing PA6 segments. PA6- b -P2000 thermoplastic elastomers were then obtained by the amide exchange reaction of PA6 segments. The structure and properties of IA-PPA and PA6- b -P2000 were further characterized in detail. The results demonstrate that the elastomers have good thermal stability and superior elasticity, which are highly dependent on the crystallinity and phase separation structure of the polyamide elastomer. Using this flexible approach, multifunction TPAEs can be designed and commercialized in a short time.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
Foods
·
2020
·Vol. 9
·期 4
·503
·
IF 4.092
Yanli Ma,Ruijin Yang,Wei Zhao
Gelatin is a promising candidate for making bioplastic film; however, the water soluble property has limited its applications. Here, we have successfully fabricated a water-insoluble gelatin film with the assistance of biocatalysis. This innovative gelatin film could retain its original shape at ambient temperature (30 °C) or even in boiling water. Type E gelatin could form more covalent crosslinks when compared to that of conventional ones with the same amount of microbial transglutaminase (MTGase), and it exhibits obvious changes in terms of molecular weight, network structure, and mechanical strength. This work could provide a strategy for fabricating water-insoluble gelatin film and open routes for the development of bioplastic film using gelatin.Keywords:gelatin;glutamine;microbial transglutaminase;crosslink;water-insoluble
研究领域:
材料科学
·
生物化学
✓ 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）