ACS Omega
·
2026
·Vol. 11
·期 29
·43288-43299
·
IF 5.2
Li Qiulin,Wang Qiuhong,Li Gang,Han Xiang,Su Bin,Liu Jing,Zhou Anning,Luo Zhenmin,Chen Fuxin
The nitrogen-containing
compounds in coal tar have always
been
an essential focus in the field of sustainable resources. They play
a crucial role in the full utilization of coal-derived energy substances.
The molecular-level structural characterization and quantitative analysis
of nitrogen-containing compounds in coal tar represent key challenges
for the energy and chemical industries. However, the two-dimensional 1 H– 15 N HMBC method suffers from limitations
in quantitative applications owing to low signal sensitivity and poor
compatibility with internal standards. This study screened and validated
a small-molecule internal standard and systematically investigated
its linear response characteristics across various nuclear magnetic
resonance experiments ( 1 H NMR, 19 F NMR, 13 C NMR, 1 H– 13 C HMBC, 1 H– 13 C HSQC, and 1 H– 15 N HMBC). The results showed that the internal standard exhibited
a good linear relationship ( R 2 ≥
0.984) under all tested pulse sequences within a specified concentration
range. In the 1 H– 15 N HMBC experiment,
the peak integral values of the internal standard signal showed excellent
linear correlation with the characteristic signal integral values
of various quinoline compounds ( R 2 ≥
0.957). The internal standard was applied to the analysis of raw and
nitrogen-doped coal tar samples, successfully enabling signal identification
and relative quantification of specific nitrogen-containing compounds
in nitrogen-doped tar, and clearly revealing the structural evolution
patterns in the transformation of particular nitrogen functional groups
during pyrolysis. The cross-sequence linear internal standard developed
in this study addresses the poor internal standard compatibility of
internal standards for quantitative analysis using multipulse NMR
sequences in complex matrices, which helps reduce intersequence systematic
errors, achieve cross-validation, and streamline experimental design
and sample preparation in future applications, and provides a novel
strategy and reliable data support for the quantitative application
of 1 H– 15 N HMBC technology in the fields
of energy and materials.
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Food Frontiers
·
2026
·Vol. 7
·期 4
·e70315
·
IF 6.3
Hui Yan,Cheng-Xi Feng,Zhe Wang,Jun-Qiao Wang,Shao-Ping Nie
Structural characterization of complex carbohydrates remains challenging. This study employed methylation, acid hydrolysis, 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization, and ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) to determine monosaccharides, glycosidic linkages, and sequence of polysaccharides. Combined with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF MS) and nuclear magnetic resonance (NMR), the structure of two fractions (GEP-60 and GEP-60S) obtained from Gastrodia elata Blume was characterized. Both fractions contained mainly glucose, and GEP-60 was homogeneous polysaccharide (25.5 kDa), while GEP-60S was mixture of lower molecular weight (DP ≤ 24) fractions. Their primary glycosidic linkage was →4)-α-Glc p -(1→, with respective percentages of 78.41 ± 2.18% and 79.72 ± 1.98%. Sequence analysis identified both contained [→4)Glc(1→] 4 , [→4)Glc(1→] 5 , and [→4)Glc(1→] 6 . NMR confirmed that both polysaccharides possessed main chain composed of →4)-α-Glcp-(1→ and substituted with α-Glcp-(1→ branches. Taken mass spectrometry and NMR spectroscopy results together, polysaccharides in G. elata Blume were α-1,4-glucan with different molecular weight containing branches substituted at C-6, with occasional substitution also observed at the C-2 and C-3. These findings provided comprehensive structural insights into G. elata Blume polysaccharides and validated feasibility of UPLC–MS/MS as an alternative strategy for analyzing plant polysaccharides.
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CEMENT & CONCRETE COMPOSITES
·
2024
·
IF 10.8
Lixiao Zhao,Pan Feng,Jinxiang Hong,Qi Liu,Guoqing Geng
Water-soluble organic admixtures (WSOAs) are widely used in cementitious materials, and may affect the porosity, but their effects on low-field nuclear magnetic resonance (LF-NMR) measurement are often overlooked. Using viscosity modifying admixture (VMA) as an example, this study demonstrates the presence of WSOAs would lead to an overestimation of porosity and a leftward shift of pore size distribution using LF-NMR. This is attributed to the formation of hydrogen bonds between polymer and water molecules, and the decreased distance between nuclear spins, respectively. A strategy is proposed to improve the accuracy of the porosity characterization by eliminating the additional effects of WSOAs in LF-NMR testing. The results show that the addition of small molecular mass non-ionic VMAs replacing mixing water (within a 20 % replacing rate) does not alter the porosity of the paste. This method can be extended to characterize the porosity of various porous materials containing WSOAs.
研究领域:
材料科学
·
化学工程
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ORGANIC & BIOMOLECULAR CHEMISTRY
·
2024
·
IF 2.9
Ting Jiang,Qian Zhou,Kang-Kang Yu,Shan-Yong Chen,Kun Li
N
6
-Methyladenosine (6mA) is a well-known prokaryotic DNA modification that has been shown to play epigenetic roles in eukaryotic DNA. Accurate detection and quantification of 6mA are prerequisites for molecular understanding of the impact of 6mA modification on DNA. However, the existing methods have several problems, such as high false-positive rate, time-consuming and complex operating procedures. Chemical sensors for the selective detection of 6mA modification are rarely reported in the literature. Fluorinated phenylboronic acid combined with 19F NMR analysis is an effective method for determining DNA or RNA modification. In this study, we presented a simple and fast chemical method for labelling the 6th imino group of 6mA using a boric-acid-derived probe. Besides, the trifluoromethyl group of trifluoromethyl phenylboronic acid (2a) could detect 6mA modification through 19F NMR. Combined with this sensor system, 6mA modification could be detected well and quickly in 6 types of deoxynucleoside mixtures and DNA samples. Taken together, the method developed in the current study has potential for specific detection of 6mA in biological samples.
研究领域:
生物化学
·
分子生物学
·
分析化学
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JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Caifang Ning,Hui Ma,Christian Marcus Pedersen,Hui Chang,Yingxiong Wang,Yan Qiao
Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant with serious negative health effects, and removal of it from water is therefore highly relevant for environmental safety. In this paper, poly(amidoamine) (PAMAM) dendrimers have been proposed as hosts for the PFOA in order to remove it from aqueous solutions. The different aggregate structures for PAMAM-PFOA complexes with increase of −COO − /−NH 3 + molar ratios were proposed on the basis NMR titrations using 19 F NMR and further analyzed by the relaxation and diffusion measurements. It is suggested that PFOA micelles are transferred to the bilayer with increasing PAMAM concentration. Moreover, the protonated surface amine groups of PAMAM contribute to reduce the critical aggregation concentration (CAC) of PFOA. The study shows that the main driving force for interaction between PAMAM and PFOA is ionic interaction. This research will serve as a starting-point for removing the fluorinated contamination by using PAMAM dendrimers.
研究领域:
环境科学
·
化学
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Applied Sciences-Basel
·
2019
·Vol. 9
·期 11
·2240
·
IF 2.217
Chunpeng Wan,Yuting Shen,Muhammad Farrukh Nisar,Wenwen Qi,Chuying Chen,Jinyin Chen
Carvacrol (5-Isopropyl-2-methylphenol), a volatile oil constituent, mainly exists in Labiaceae family plants. Carvacrol has long been studied for its natural antifungal potential and food preservative potential. However, its exact mode of action, especially againstPenicillium digitatum(P. digitatum), remains unexplored. Herein, a1H-NMR-based metabolomic technique was used to investigate the antifungal mechanism of carvacrol againstP. digitatum. The metabolomic profiling data showed that alanine, aspartate, glutamate, and glutathione metabolism were imbalanced in the fungal hyphae. A strong positive correlation was seen between aspartate, glutamate, alanine, and glutamine, with a negative correlation among glutathione and lactate. These metabolic changes revealed that carvacrol-induced oxidative stress had disturbed the energy production and amino acid metabolism ofP. digitatum. The current study will improve the understanding of the metabolic changes posed by plant-based fungicides in order to control citrus fruit green mold caused byP. digitatum. Moreover, the study will provide a certain experimental and theoretical basis for the development of novel citrus fruit preservatives.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 28
·期 1
·1052-1060
·
IF 3.056
Sun Xu,Xu Li,Jiang Weina,Xuan Yan,Lu Wen,Li Zhong,Yang Shilong,Gu Zhenzhen
In the present study, a magnetic adsorbent, rhein-coated magnetic Fe 3 O 4 nanoparticle (RMNP), for Pb 2+ and Mg 2+ had been developed, and adsorption mechanism was studied via low-field NMR. RMNP was characterized by TEM, FTIR, and XRD. RMNP could adsorb and remove Pb 2+ and Mg 2+ from water and was successfully applied to remove Pb 2+ and Mg 2+ from wastewater, with satisfactory recovery rates and high adsorption capacities. The calculated maximum adsorption capacity for Mg 2+ and Pb 2+ was approximately 69.3 and 64.9 mg g −1 of RMNP, respectively, which was better than some results reported. Low-field NMR results showed that Pb 2+ or Mg 2+ enhanced the T 2 relaxation time of RMNP, which suggested that RMNP selectively coordinated with Pb 2+ or Mg 2+ and led to the aggregation of RMNP, furthermore removal of Pb 2+ or Mg 2+ from water. The standard curves for △T 2 -cation concentration exhibited good line correlation. The linear ranges were from 4.2 × 10 −6 to 2.0 × 10 −4 mol L −1 for Pb 2+ and from 5.0 × 10 −6 mol L −1 to 1.0 × 10 −4 mol L −1 for Mg 2+ , respectively. The limits of detection were 1.4 × 10 −6 mol L −1 for Pb 2+ and 2.1 × 10 −6 mol L −1 for Mg 2+ , respectively. In short, low-field NMR could clearly display the interaction between RMNP and Pb 2+ or Mg 2+ , even be used to detect Pb 2+ or Mg 2+ in suitable condition. Besides, this method could be expanded to study the interaction between other magnetic adsorbents and analytes.
研究领域:
环境科学
·
材料科学
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CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Qi Shi,Jingyu Yan,Bin Jiang,Xiujuan Chi,Jihui Wang,Xinmiao Liang,Xuanjun Ai
Two-dimensional NMR spectroscopies are one of the most frequently used techniques for the structural determination of carbohydrates . However, the data analysis is challenging because of the signal overlap in the 1 H homonuclear correlation spectra. We attempted to explore a general strategy for the structural determination of carbohydrates by combined multi-dimensional spectroscopies . The strategy was applied to a human milk oligosaccharide lacto-N-difucohexaose I, that has been previously studied by conventional two-dimensional NMR spectroscopy. Assignment of the intra-residue resonances of the hexasaccharide using the three-dimensional spectrum was straightforward. Consequently, data analysis of the multi-dimensional spectra was significantly simplified, leading to a quicker determination of the intra- and inter-residue connections in the hexasaccharide. Application of the NMR strategy to chondroitin sulfate from bovine cartilage revealed two repeating disaccharide regions of the A and C units of chondroitin sulfate, indicating the high potential of this technique for the structural determination of complex polysaccharides .
研究领域:
化学
·
生物化学
·
光谱学
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INTERNATIONAL DAIRY JOURNAL
·
2020
·
IF 2.512
Ling Jin,Ting Li,Tan Yang,Xuehua Liang,Bin Wu,Dengchao Zou,Liwen Hu,Ganhui Huang,Jinsheng Zhang
The monitoring and control of foodborne pathogenic microorganisms to protect food safety is of great significance. A biosensor based on superparamagnetic ultra-small iron oxide nanoparticles (USIO NPs) combined with membrane filtration and low field nuclear magnetic resonance (LF-NMR) for rapid detection of Salmonella is introduced. First, free biotin-capture-antibodies and biotin-detection-antibodies were specifically bound to different targets of Salmonella in milk samples. Then streptavidin-coated USIO NP probes were coupled with the biotinylated monoclonal antibody to capture Salmonella . Finally, polyethersulfone membrane filtration was performed on the final reaction system to remove unbound-probes, and the transverse magnetisation time (T 2 ) of the filtrate was measured by NMR to indirectly reflect the content of the target substance retained on the filter membrane. This method shows high specificity and anti-interference to Salmonella , and the limit of detection (LOD) in pure culture and real samples was 2.3 × 10 3 cfu mL −1 within 150 min.
研究领域:
食品安全
·
微生物学
·
分析化学
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TOXICOLOGY LETTERS
·
2018
·
IF 3.166
Ling-Yu Ruan,Jun-Ting Fan,Wei Hong,He Zhao,Ming-Hui Li,Lei Jiang,Yong-Hong Fu,Yue-Xiao Xing,Cheng Chen,Jun-Song Wang
Isoniazid (INH) is a well-known therapeutic and preventive agent against tuberculosis. However, high rates of side effects with various symptoms concerning hepatotoxicity and neurotoxicity have been reported, hindering its wide and safe application in clinic. In this investigation, rats were intoxicated with INH by gavage at doses of 200 and 400 mg/kg for 7 consecutive days to develop a rat model of acute INH-induced toxicity, which was investigated by a 1 H NMR-based metabolomics complemented with clinical assays, histopathological inspection and western blotting. INH decreased the weights of dosed rats and induced seizure and hepatic steatosis dose-dependently. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of the NMR profiles of rat livers, brains and serum revealed that INH dose-dependently induced oxidative stress, disorders of excitatory and inhibitory amino acid neurotransmitters, and disturbances of energy metabolism and osmotic balance, which could help clarify the mechanisms of INH-induced hepatotoxicity and neurotoxicity. This integrated metabolomics approach showcased its ability to characterize the global metabolic status of organism, providing a powerful and feasible tool to probe drug induced toxicity or side effects.
研究领域:
药理学
·
毒理学
·
代谢组学
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APPLIED MAGNETIC RESONANCE
·
2018
·Vol. 50
·期 1
·357-370
·
IF 0.835
Lu Rongsheng,Lei Pengkun,Yang Qing,Ni Zhonghua,Yi Hong
In this work, a low-field microfluidic nuclear magnetic resonance (NMR) detection device was developed by fabricating a multi-layer microfluidic NMR probe. In combination with biological sensor technology based on immunomagnetic nanoparticles (IMNPs), the microfluidic NMR detection device was used to rapidly distinguish the concentration of target tumor markers. The experimental results show that the concentration of the target tumor markers can be differentiated with high sensitivity and specificity by the rate of the transverse relaxation time change Δ T 2 even with interference from other biomarkers. A good linear relationship between Δ T 2 and the concentration of the target tumor markers was also found, indicating that the microfluidic NMR device could be used for quantitative detection of tumor markers. Finally, the validity of the microfluidic NMR device for detecting target tumor markers was proved by comparison with a commercial cell counter, and the results detected by the two devices have a good consistency with a correlation coefficient of 0.996. In conclusion, the presented low-field microfluidic NMR device is a potential tool for the rapid and accurate quantitative detection of tumor markers.
研究领域:
生物医学工程
·
医学诊断
·
纳米技术
·
分子生物学
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Minjun Ma,Yu Liu,Honghong Chang,Yingxiong Wang,Yan Qiao
Ofloxacin is one of the most potent antibiotics. But its low solubility in water has limited its use in site targeted delivery and topical applications. This study investigates the PAMAM-NH 2 (amine-terminated polyamidoamine dendrimers) delivery of ofloxacin in water based on host-guest chemistry and reveals the interaction mechanism of PAMAM-NH 2 with ofloxacin by utilizing NMR techniques including 1D chemical shift titration, 2D 1 H– 13 C HSQC titration, NOESY technique, STDD method, and 2D DOSY analysis. Ofloxacin interacts with surface amine groups of PAMAM-NH 2 via ionic interactions, and ofloxacin is also encapsulated into the PAMAM interior cave through hydrophobic interactions. An overall mechanism was proposed for the PAMAM-NH 2 adsorption of ofloxacin, and then the binding affinity was determined. The experimental data demonstrate the potential of the PAMAM-NH 2 for the drug molecules delivery.
研究领域:
药学
·
化学
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