JOURNAL OF PHYSICAL CHEMISTRY B
·
2013
·
IF 3.607
Liqing Xie,Huiting Liu,Shuaiyuan Han,Baohua Yue,Liuming Yan
Intermolecular and intramolecular hydrogen bond (H-bond) and proton transport in acid–base complexes and amphoteric molecules consisting of phosphonic acid groups and nitrogenous heterocyclic rings are investigated by density functional theory calculations and 1H NMR and 31P NMR spectroscopy. It is concluded that a phosphonic acid group can act both as H-bond donor and H-bond acceptor, while an imine nitrogen atom can only act as H-bond acceptor and an amine group as H-bond donor. And the intramolecular H-bond is weaker than the intermolecular H-bond attributing to configurational restriction. In addition, the strongest H-bond interaction is observed between a phosphonic acid and a 1H-indazole because of the formation of double H-bonds. The 1H NMR and 31P NMR chemical shifts for the acid–base complexes are consistent with the density functional theory calculations. From the 1H NMR chemical shifts, fast proton exchange is observed between a phosphonic acid and 1H-benzimidazole or 1H-indazole. Finally, it is proposed that polymeric material tethered with 1H-benzimidazole or 1H-indazole rings is a favorable component for high-temperature proton exchange membranes based on acid–base complexes or acid–base amphoteric molecules.
研究领域:
化学
·
材料科学
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PubMed
高影响因子
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2024
·
IF 6
Yong-Jun Huang,Yi-Peng Zang,Li-Jun Peng,Ming-Han Yang,Jing Lin,Wei-Min Chen
The low permeability of the outer membrane of Gram-negative bacteria is a serious obstacle to the development of new antibiotics against them. Conjugation of antibiotic with siderophore based on the “Trojan horse strategy” is a promising strategy to overcome the outer membrane obstacle. In this study, series of antibacterial agents were designed and synthesized by conjugating the 3-hydroxypyridin-4(1 H )-one based siderophores with cajaninstilbene acid ( CSA ) derivative 4 which shows good activity against Gram-positive bacteria by targeting their cell membranes but is ineffective against Gram-negative bacteria. Compared to the inactive parent compound 4 , the conjugates 45c or 45d exhibits significant improvement in activity against Gram-negative bacteria, including Escherichia coli , Klebsiella pneumoniae and especially P. aeruginosa (minimum inhibitory concentrations, MICs = 7.8–31.25 μM). The antibacterial activity of the conjugates is attributed to the CSA derivative moiety, and the action mechanism is by disruption of bacterial cell membranes. Further studies on the uptake mechanisms showed that the bacterial siderophore-dependent iron transport system was involved in the uptake of the conjugates. In addition, the conjugates 45c and 45d showed a lower cytotoxic effects in vivo and in vitro and a positive therapeutic effect in the treatment of C. elegans infected by P. aeruginosa . Overall, our work describes a new class and a promising 3-hydroxypyridin-4(1 H )-one- CSA derivative conjugates for further development as antibacterial agents against Gram-negative bacteria.
研究领域:
微生物学
·
药理学
·
传染病学
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PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Feng Wang,Zheng Zhang,Ying Yang,He Liu,Kun Chen,Zongxian Wang,Aijun Guo
The factors leading to olefinic hydrogen signal shielding in the 1 H NMR spectra of thermally cracked vacuum residue (VR) and its heavy fractions were revealed using a series of model compound systems, and the effect of olefinic hydrogen signal shielding on the determination of olefinic hydrogen content was elucidated. There were two main factors leading to the olefinic hydrogen signal shielding in the 1 H NMR spectra of olefins in heavy fractions, i.e. intramolecular and intermolecular. For the olefin itself in heavy fractions, the chemical shift of the olefinic hydrogen closest to the aromatic ring was in the aromatic region rather than the olefinic region due to the π-π conjugation effect between the double bond and the intramolecular aromatic ring. Notably, the response intensity of the olefinic hydrogen signal could be weakened or even disappear due to the suppressive effect of the intermolecular aromatic structures in other polycyclic aromatic hydrocarbons (PAHs), while alkanes and monocyclic aromatics had little effect on the olefinic hydrogen signal response. Although the olefinic hydrogen signal was detected merely at about 5.30 ppm in the 1 H NMR spectra of heavy fractions, these olefinic structures may be predominantly of the R─CH═CH 2 type rather than the R─CH═CH─R′ type. More importantly, the measured olefinic hydrogen content of thermally cracked VR and its heavy fractions may be considerably lower than the actual content, with the measured content being only about 30–40 % of the actual content. This is mainly due to the weakening and disappearance of the olefinic hydrogen signal, coupled with the fact that the integral area of the possible olefinic hydrogen signal in the aromatic region was overlooked when calculating the total integral area of the olefinic hydrogen signal in the 1 H NMR spectrum.
研究领域:
分析化学
·
石油化学
·
有机化学
·
光谱学
·
能源化学
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DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2018
·
IF 2.831
Xu-Wen Liu,Chao-Ling Tang,Hua Zheng,Jin-Xia Wu,Fang Wu,Yi-Yi Mo,Xi Liu,Hong-Jia Zhu,Chun-Li Yin,Bang Cheng,Jun-Xiang Ruan,Fang-Ming Song,Zhao-Ni Chen,Hui Song,Hong-Wei Guo,Yong-Hong Liang,Zhi-Heng Su
Liver fibrosis is a common consequence of chronic liver diseases resulting from multiple etiologies. Furthermore, prolonged unresolved liver fibrosis may gradually progress to cirrhosis, and eventually evolve into hepatocellular carcinoma (HCC). Corydalis saxicola Bunting (CS), a type of traditional Chinese folk medicine, has been reported to have hepatoprotective effects on the liver. However, the exact mechanism of how it cures liver fibrosis requires further elucidation. In this work, an integrated approach combining proton nuclear magnetic resonance ( 1 H-NMR)-based metabonomics and network pharmacology was adopted to elucidate the anti-fibrosis mechanism of CS. Metabonomic study of serum biochemical changes by carbon tetrachloride (CCl 4 )-induced liver fibrosis in rats after CS treatment were performed using 1 H-NMR analysis. Metabolic profiling by means of partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation caused by CCl 4 was reduced after CS treatment. As a result, lipids, leucine, alanine, acetate, O -acetyl-glycoprotein and creatine were significantly restored after CS treatment, which regulated valine, leucine and isoleucine metabolism; arginine and proline metabolism; lipid metabolism and pyruvate metabolism. Additionally, 157 potential targets of CS and 265 targets of liver fibrosis were identified by means of network pharmacology. Subsequently, 5 target proteins, which are the intersection of potential CS targets and liver fibrosis targets, indicated that CS has potential anti-fibrosis effects through regulating alanine aminotransferase (ALT) activity, the farnesoid X receptor (FXR), cyclooxygenase-2 (COX-2), matrix metalloproteinase-1 (MMP-1) and angiotensinogen. Chelerythrine and sanguinarine were the potential active compounds in CS for treating liver fibrosis through regulating ALT activity. This study is the first report to study the anti-fibrosis effects of CS on the basis of combining a metabonomics and network pharmacology approaches, and it may be a potentially powerful tool to study the efficacy and mechanisms of traditional Chinese folk medicines.
研究领域:
药理学
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代谢组学
·
肝脏疾病研究
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PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2016
·
IF 2.687
Xia Wu,Han Cao,Lifang Zhao,Jianao Song,Yuqi She,Yifan Feng
Non-destructive proton nuclear magnetic resonance ( 1 H NMR) spectroscopy and highly sensitive ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (U-HPLC/Q-TOF-MS) coupled to data processing methods were applied to analyze the metabolic profiling changes of glycerophospholipids (GPLs) in RAW264.7 cells from inflammation to prognosis. Analysis of 1 H NMR was shown that the models were grouped successfully, illustrating that all of them had significant differences. Based on the highly simple, accurate, non-targeted and non-destructively advantages of 1 H NMR, it could be used as a new screening tool of anti-inflammatory drugs in the metabolic profiling of GPLs. 58 GPLs were identified by U-HPLC/Q-TOF-MS, and 19 components were firstly identified in this study compared with our previous results. In addition, ten potential biomarkers were proved, of which phosphatidylcholine (PC) (16:0/18:1) and (18:0/18:1) changed consistently in three drug-induced groups and might be the important biomarkers. Compared with 1 H NMR, U-HPLC/Q-TOF-MS showed higher sensitivity and specificity and was more suitable for the determination of biomarkers apart from the deficiency of time-consuming sample preparation steps and unambiguous metabolite identification. Therefore, it is feasible to analyze the changes of GPLs during inflammation by combining 1 H NMR spectroscopy with U-HPLC/Q-TOF-MS. The metabolic profiling of GPLs provides valuable evidence for inflammation diagnosis and prognosis, and might unravel the mechanisms involved in inflammation progression.
研究领域:
代谢组学
·
药理学
·
生物化学
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DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2019
·Vol. 75
·期 12
·3273-3281
·
IF 3.255
Bao-Lei Wang,Hong-Wei Zhu,Zheng-Ming Li,Xiao Zhang,Shu-Jing Yu,Yi Ma,Hai-Bin Song
BACKGROUND N -Pyridylpyrazole derivatives have received continuous attention in agrochemical research during the last decade owing to their remarkable insecticidal or fungicidal potentials. To look for novel heterocyclic agrochemicals for increasing production of agriculture, a series of novel α -aminophosphonate derivatives containing N -pyridylpyrazole moiety were synthesized. RESULTS The structures of the title compounds were confirmed via melting point, IR, 1 H NMR, 13 C NMR, 31 P NMR, HRMS and elemental analysis. The single crystal structure of diethyl (3-bromo-1-(3-chloropyridin-2-yl)-1 H -pyrazol-5-yl)(2,6-dimethylphenylamino)methylphosphonate (compound 12b) was first reported. Moreover, the bioassays displayed that the title compounds exhibited modest or weak insecticidal activities against oriental armyworm at 200 μg mL −1 . The first investigation on the fungicidal potential of chlorantraniliprole showed no significant activities towards the six tested fungi found in this study, however, most of the title compounds displayed apparent in vitro fungicidal activity against some plant fungi, in particular excellent activities towards Physalospora piricola . Compounds 11a and 11b had EC 50 values of 18.8 and 17.4 μg mL −1 , respectively, which were comparable with that of fungicide control triadimefon (EC 50 = 24.7 μg mL −1 ) against Physalospora piricola . In addition, some compounds exhibited modest in vivo control efficacy at 0.5 mg mL −1 towards Sclerotinia sclerotiorum (11b: 30.1(±1.8)%), Rhizoctonia cerealis (11a: 20.4(±2.1)%; 11b: 30.2(±2.2)%), and Erysiphe graminis (11a: 30.3(±1.8)%; 12d: 40.2(±0.9)%). CONCLUSION Compounds 11a, 11b and 12d could be promising new lead structures for the development and discovery of novel fungicides towards Physalospora piricola and Erysiphe graminis . The structure-activity relationship (SAR) analysis provided useful guidance and new understanding for the design of novel pyridylpyrazole-containing agrochemicals. © 2019 Society of Chemical Industry
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PubMed
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yunfei Liu,Yayu Feng,Yue Sun,Meijing Zhang,Pengfei Zhang,Ronghui Zhao,Kuilin Deng
In this investigation, a nonconjugated fluorescent polyamide with piperazine and valerolactam moieties (PAM–PV) has been synthesized by the modified Ugi polymerization using 1,4-bis(3-aminopropyl)piperazine, levulinic acid, and 1,4-bis(3-isocyanopropyl)piperazine as monomers. In the polymerization, the special construction of levulinic acid leads to the formation of valerolactam on PAM–PV chains via the Mumm rearrangement. PAM–PV shows a strong fluorescence emission at 428 nm due to the intramolecular aggregation of piperazine and valerolactam moieties along the backbone. Impressively, PAM–PV can specifically detect NO2– ions via static quenching with a linear range of 10–6–10–5 M and a detection limit of 0.6 μM (0.0276 mg/L), which was far less than the minimum allowable concentration of 3 mg/L for NO2– in drinking water specified by WHO. Furthermore, the several common anions and cations have no interference effects on the specific detection of PAM–PV to NO2– ions. The quenching mechanism of NO2– and PAM–PV by FTIR, UV, and 1H NMR measurements indicates that the strong electrostatic interaction between NO2– and PAM–PV makes the macromolecular chains more relaxed and outstretched, leading to a formation of a nonfluorescent complex. Moreover, the practical detection of NO2– in the three water bodies, sauerkraut, and ham sausage and the fabrication of a portable detecting paper to NO2– ions were conducted in this experiment.
研究领域:
聚合物化学
·
分析化学
·
环境科学
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DOI
高影响因子
Arabian Journal of Chemistry
·
2017
·
IF 4.553
Gang Chen,Jiaheng Lei,Yong Du,Xiaodi Du,Xuebing Chen
A novel polycarboxylate superplasticizer (PCE) with a long polyoxyethylene (PEO) chain and a terminal carboxylic group was synthesized from a modified polyether (SAE-IPEG) to increase its performance in cement. The molecular structure of the PCE was characterized by infrared spectroscopy and 1 H nuclear magnetic resonance (NMR) spectroscopy. The performance of synthesized PCE in cement was studied in the absence and the presence of montmorillonite (Mmt) clay. It was found that the PCE disperses in cement uniformly without aggregation, which is different significantly from the conventional PCEs. Adsorption measurements and X-ray diffraction analysis revealed that the synthesized PCE only interacted with Mmt via surface adsorption, whereas the conventional PCEs interact with the clay through the surface adsorption and the chemical intercalation. Such dramatic change could be ascribed to the introduction of an electronegative carboxylic acid group as a terminal group into the long polyoxyethylene chain of PCE, which reduced the adsorption and enhanced tolerance of PCE on Mmt.
研究领域:
材料科学
·
化学工程
·
土木工程
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高影响因子
DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 24
·9216-9225
·
IF 4.097
Qiong Wu,Tianfeng Chen,Zhao Zhang,Siyan Liao,Xiaohui Wu,Jian Wu,Wenjie Mei,Yanhua Chen,Weili Wu,Lingli Zeng,Wenjie Zheng
Two arene Ru(II) complexes coordinated by 2-(3-methoxyphenyl)imidazole[4,5-f][1,10]phenanthroline, [(η6-RC6H5)Ru(m-MOPIP)Cl]Cl (R = H, 1; R = CH3, 2), have been prepared under microwave irradiation; the crystal structure of 2 exhibits a typical “piano stool” conformation, with bond angles for N1–Ru1–Cl1 86.02 (14)° and N2–Ru1–Cl1 84.51 (14)°. The Ru–C distance for the Ru atom bound to the benzene ring is about 0.2178(8) nm, and the average Ru–N distance for Ru atom to the two chelating N atoms is about 0.2092(4) nm. The evaluation of in vitro anticancer activities revealed that these synthetic Ru(II) complexes selectively inhibited the growth of HepG2 hepatocellular carcinoma cells, with low cytotoxicity toward LO2 human normal liver cells. The results demonstrated that the complexes exhibited great selectivity between human cancer and normal cells by comparing with the ligand m-MOPIP. Furthermore, complexes 1 and 2 could bind to c-myc G4 DNA in groove binding mode in promising affinity, and the insertion of the methyl groups in the arene ligand contributed to strengthen the binding affinity. This was also confirmed by molecular docking calculation and 1H NMR analysis which showed that both 1 and 2 can bind in the loop constructed by A6–G9 and G21–A25 base pairs in c-myc G4 DNA to block the replication of c-myc oligomer. Taken together, these results suggest that arene Ru(II) complexes display application potential as small molecule inhibitors of c-myc G4 DNA.
研究领域:
无机化学
·
药物化学
·
癌症研究
·
DNA相互作用
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DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 34
·期 3
·e5454
·
IF 3.259
Ningbo Li,Yijun Wang,Feijun Liu,Xin Zhao,Xinhua Xu,Quan An,Keming Yun
An air-stable complex of zirconium (IV)-salophen perfluorooctanesulfonate ( 1 ) was successfully synthesized by reacting Zr (salphen)Cl 2 and C 8 F 17 SO 3 Ag. Complex 1 was characterized and studied by different techniques (NMR, IR, HRMS, TG-DSC, conductivity and acidity measurements), and was found to be air-stable, water tolerant, thermally stable and strongly Lewis-acidic. Complex 1 exhibited high catalytic efficiency for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones via the Biginelli reaction of aldehydes, 1,3-dicarbonyl compounds and urea/thiourea under solvent-free conditions. Furthermore, complex 1 could be reused 5 times with minimal changes in catalytic efficiency. Compared with previously reported methods, the important features of this protocol are the solvent-free conditions, the short reaction times, the wide substrate compatibility, the high efficiency and the good reusability.
研究领域:
化学
·
催化科学
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DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2015
·Vol. 641
·期 5
·911-916
·
IF 1.16
Fugang Li,Wenyuan Zhao,Sitong Chen,Tonglai Zhang,Zunning Zhou,Li Yang
Two nitrogen-rich alkali metal salts based on nitrogen-rich anion [Zn(bta) 2 ] 2– : {[Na 2 Zn(bta) 2 (H 2 O) 8 ] · H 2 O} n ( 1 ) and {[K 2 Zn(bta) 2 (H 2 O) 4 ]} n ( 2 ) were synthesized by reactions of alkali hydroxide, N , N -bis(1 H -tetrazol-5-yl)amine (H 2 bta), and zinc chloride in aqueous solutions. The crystal structures of 1 and 2 were determined by low temperature single-crystal X-ray diffraction and fully characterized by elemental analysis and FT-IR spectroscopy. The structures demonstrate that an infinite 1-dimensional (1D) chain structure is constructed by Na + ions and bridging water molecules in compound 1 , which is connected by extensive hydrogen bonds forming a complex 3D network, whereas compound 2 features a more complicated 3D metal-organic framework (MOF). The thermal behaviors of 1 and 2 were investigated by differential scanning calorimetry (DSC) measurements. The DSC results illustrate that both compounds exhibit high thermal stabilities (decomposition temperature > 345 °C). In addition, the heats of formation were calculated on the basis of the experimental constant-volume energies of combustion measured by using bomb calorimetry. Lastly, the sensitivities towards impact and friction were assessed according to Bundesamt für Materialforschung (BAM) standard methods.
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高影响因子
HYDROMETALLURGY
·
2023
·
IF 4.7
Shaoping Feng,Kun Huang
Dialkylsulfide is considered as the most promising extractant for separating Pd(II) and Pt(IV) in industrial processes. However, the slow kinetics for Pd(II) extraction limits its extensive application. The development of new extractants with faster kinetics, high extraction efficiency, and exceptional Pd(II) separation selectivity has been a persisting goal over the past few decades. In this study, a new functionalized extractant, 1-methyl-2-(nonylthio)-1H-imidazole (MNI) containing both N and S atoms, was synthesized and employed to separate Pd(II) from mixed hydrochloric acid solutions with different initial Pd(II)/Pt(IV) concentration ratios. Experimental results revealed that MNI not only has a high selectivity for Pd(II) over Pt(IV) but also has faster kinetics for Pd(II) extraction than diisopentylsulfide (S201) under similar extraction conditions. In contrast to traditional dialkylsulfide extractants, MNI coordinates with Pd(II) ions via the N(5) atom in its imidazole ring to form Pd(MNI) 2 Cl 2 complexes, instead of using the S atom as with dialkylsulfide. The extraction mechanism involving the coordination between Pd(II) and MNI was demonstrated using the slope analysis method and ultraviolet (UV), Fourier-transform infrared (FT-IR), 1 H NMR, and 13 C NMR spectroscopic methods. The fast extraction kinetics between MNI and Pd(II) was possibly attributed to the high charge density of the N(5) atom in the imidazole ring, whereas the outstanding separation selectivity for Pd(II) was due to the strong affinity of the N(5) atom. The facile synthesis, high saturation capacity, excellent Pd(II) selectivity, and remarkable reusability endow MNI with potential applications in Pd(II) recovery from leach solutions of waste automotive catalysts and other secondary resources.
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