MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Yao Wei,Hua Jiang,Pengchi Deng
Sulfhydryl-containing amino acids had a variety of biological functions. Herein, a method was simply set up to determine Cys and GSH with β-CD AgNPs quantitatively. The chemical shifts of Cys and GSH both moved to higher field when β-CD AgNPs were added. The reason was that the sulfhydryl groups could bind to the surface of AgNPs. In addition, the competitive effect of Cys and GSH in mixed solutions was explored via the 1 H chemical shift deviation. Peaks at 3.05 ppm and 2.93 ppm were selected as characteristic signals. This method exhibited an excellent linearity in the range of Cys and GSH in 0.1–20 mM. The detection limits of Cys and GSH were 40 μM and 14 μM, respectively. This method was successfully used to quantitatively determine Cys and GSH in human serum and urine.
研究领域:
分析化学
·
生物化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Kecheng Li,Andrew R. Green,Meredith M. Dinges,Cynthia K. Larive
Chitin oligosaccharides , composed of homogeneous β(1 → 4)-linked N -acetyl-D-glucosamine (GlcNAc) sequences, is a well-known elicitor of plant immune defense, and also occur as structural elements of chitosan and nodulation (Nod) factor. Detailed microstructure characterization is required for understanding the function mode of these bioactive molecules. Herein, experimental conditions for detection and elucidation of the 1 H NMR resonances of amide groups in chitin oligosaccharides are presented. The binary mixture of 70% H 2 O: 30% DMSO‑ d 6 was found to be the optimal solvent for amide proton measurements in homogeneous GlcNAc sequences, facilitating differentiation of the local chemical microenvironments of all four amide groups of the chitin tetrasaccharide . Experimental evidence that anomeric end-effect triggers amide proton resonance differentiation at the adjacent residue has potential to provide important insights into the solution structure of chitin and other amino sugars containing GlcNAc sequences.
研究领域:
生物化学
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植物免疫学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2019
·
IF 5.399
Ting Shi,MengTing Zhu,XingYu Zhou,Xi Huo,You Long,XiangZhong Zeng,Yi Chen
Proton nuclear magnetic resonance ( 1 H NMR) combined with partial least squares (PLS) was developed for the rapid determination of squalene and sterols (brassicasterol, campesterol, stigmasterol and β-sitosterol) in 119 vegetable oils from 7 different species. The 1 H NMR spectra of these oil samples were correlated to the reference value determined by gas chromatography-mass spectrometry (GC–MS) method by PLS regression, using outlier removal, selection of input X-variables and data pretreatments. Auto-scaling (UV) was chosen as the best pre-processing for the PLS models of stigmasterol, β-sitosterol, and squalene. Pareto variance (Par) was more suitable for the PLS model of brassicasterol. The model for squalene was further improved by a reduced number of variables with variable importance for the projection (VIP) scores technique. The study demonstrated the potential application of NMR coupled with PLS as a rapid and nondestructive technique for the routine analysis of squalene and sterols in vegetable oils.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2015
·Vol. 117
·期 7
·918-925
·
IF 1.812
Ziliang Song,Yong Wang,Guoqiang Li,Wei Tan,Shengwen Yao
A new approach for determination of glycidyl fatty acid esters (GDEs) based on 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy was developed. The 1 H NMR spectra of the GDE standards were prepared and characterized. The quantification formula was then deduced from the characteristic signals of two epoxy methylene (CH 2 ) protons at chemical shifts 2.56 and 2.76 ppm. Tests on repeatability, reproducibility, and recovery were conducted and proved the reliability of the quantification method. This method was extended to GDEs mixed with oil matrices composed of different acylglycerols (GREs). The weighted average factor f w is introduced to calculate the fatty acid composition based on the stoichiometric proportion of the lipid component and its esterification degree. With the fatty acid composition determined, the molar percentage obtained from 1 H NMR can be converted to the weight percentage. This method is an analytical model for the determination of GDEs, with advantages such as easy operation and high accuracy. Practical applications: Heat treatment of edible oils in the refinery process can generate GDEs, a group of contaminants having potential risks to liberate a carcinogenic compound called glycidol during digestion of oil in the human body. It has become an important issue for the oil industry to develop an effective method for the determination of GDEs. The proposed 1 H NMR spectroscopic method is able to characterize and quantify GDEs in an accurate, rapid, and noninvasive way. With these advantages, the analytical results also provide quantitative criteria for subsequent concentration and mitigation of GDEs in refined edible oils. A novel 1 H NMR spectroscopic method was developed to determine glycidyl fatty acid esters (GDEs), a processing contaminant in refined edible oil.
研究领域:
食品科学
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分析化学
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产品关联
DOI
高影响因子
Membranes
·
2023
·Vol. 13
·期 1
·61
·
IF 4.2
Olga Yu. Selyutina,Anna V. Mastova,Nikolay E. Polyakov
Anthracycline antibiotics, e.g., doxorubicin, daunomycin, and other anthraquinones, are an important family of antitumor agents widely used in chemotherapy, which is currently the principal method for treating many malignancies. Thus, development of improved antitumor drugs with enhanced efficacy remains a high priority. Interaction of anthraquinone-based anticancer drugs with cell membranes attracts significant attention due to its importance in the eventual overcoming of multidrug resistance (MDR). The use of drugs able to accumulate in the cell membrane is one of the possible ways of overcoming MDR. In the present work, the aspects of interaction of anthraquinone 2-phenyl-4-(butylamino)naphtho[2,3-h]quinoline-7,12-dione) (Q1) with a model membrane were studied by means of NMR and molecular dynamics simulations. A fundamental shortcoming of anthracycline antibiotics is their high cardiotoxicity caused by reactive oxygen species (ROS). The important feature of Q1 is its ability to chelate transition metal ions responsible for ROS generation in vivo. In the present study, we have shown that Q1 and its chelating complexes penetrated into the lipid membrane and were located in the hydrophobic part of the bilayer near the bilayer surface. The chelate complex formation of Q1 with metal ions increased its penetration ability. In addition, it was found that the interaction of Q1 with lipid molecules could influence lipid mobility in the bilayer. The obtained results have an impact on the understanding of molecular mechanisms of Q1 biological activity.Keywords:anthraquinones;NMR;molecular dynamics;lipid membranes
研究领域:
药理学
·
生物物理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2010
·
IF 3.471
Dongfang Zhang,Liuming Yan
The acid−base equilibrium in acid (phenylphosphonic acid, methylsulfonic acid, phosphoric acid, hydrochloric acid, acetic acid, and sulfuric acid)−benzimidazole (BIm) complexes was studied by 1H NMR spectra, FTIR spectra, and density functional theory (DFT) calculations. The DFT optimized structures of the acid−BIm complexes, the vibrational frequencies of the acidic protons, and potential profiles were applied to study the equilibrium between the acids and BIm. In gas phase, it was shown that the strong sulfuric acid could completely protonate BIm and the other acids could only incompletely protonate BIm. When the polarizable continuum model of DMSO was applied, it was shown that all the acids could completely protonate BIm, except the weak acetic acid and phenylphosphonic acid. Furthermore, the potential profile for the PPoA−BIm shows double-well structure facilitating the free movement of the acidic proton between PPoA and BIm. If an explicit solvent molecule of DMSO was included into an acid−BIm complex, significant changes in equilibrium between acid and BIm are observed. The potential profiles for the MSA−BIm and HCl−BIm show very flat bottom wells, facilitating the free movement of proton between the acid and BIm. These calculations were consistent with the 1H NMR chemical shifts of the immobile protons of the benzimidazole ring in DMSO-d6 and the FTIR spectra of the acid−BIm complexes.
研究领域:
物理化学
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计算化学
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光谱学
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理论化学
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有机化学
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DOI
高影响因子
CATALYSIS TODAY
·
2021
·
IF 6.766
Jiyuan Fan,Saumitra Saxena,Chengkun Xiao,Jinlin Mei,Gang Wang,Aiping Chen,Wen Zhang,Haidong Li,Aijun Duan,William L. Roberts
Oxidative desulfurization of model oil and heavy fuel oil (HFO) was investigated under mild conditions using H 2 O 2 as an oxidant and acetonitrile as an extractant. The influence factors in the oxidation and extraction processes were evaluated and optimized. The molecular characteristics of the raw feedstock and the desulfurized oils, and the corresponding extraction phases were systematically analyzed by APPI FT-ICR MS, 1 H NMR, etc. The results showed that the desulfurization rate of dibenzothiophene reached 97.7% after 10 min reaction, while the sulfur removal efficiency of HFO was 30.7% under optimized conditions. The structures of sulfur compounds were described in heteroatom type, carbon number distribution vs unsaturation degree. The detected main sulfur-containing compounds are S 1 , S 2 , S 3 , NS, OS, O 2 S, O 2 S 2 , and O 4 S 2 . Based on the APPI FT-ICR MS results, it can be found that almost all the S 1 species have been transformed into sulfone after the oxidation process. Furthermore, the sulfone of O 2 S 1 and O 4 S 2 species in extraction phases were in double bond equivalent (DBE) range from 9 to 25 and carbon number with ≤ 40. 1 H NMR results showed that the α to aromatic CH 3 combined naphthenic CH-CH 2 group accounted for 73.2% in the extraction phase.
研究领域:
化学工程
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分析化学
·
环境科学
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DOI
高影响因子
BIOCHEMICAL JOURNAL
·
2020
·Vol. 477
·期 10
·1923-1937
·
IF 4.097
Cai Aimin,Zheng Hailun,Chen Zhiwei,Lin Xinlu,Li Chen,yao Qing,Bhutia Yangzom D.,Ganapathy Vadivel,Chen Ruijie,Kou Longfa
Gemcitabine is the first-line chemotherapy for pancreatic cancer. To overcome the often-acquired gemcitabine resistance, other drugs are used in combination with gemcitabine. It is well-known that cancer cells reprogram cellular metabolism, coupled with the up-regulation of selective nutrient transporters to feed into the altered metabolic pathways. Our previous studies have demonstrated that the amino acid transporter SLC6A14 is markedly up-regulated in pancreatic cancer and that it is a viable therapeutic target. α-Methyltryptophan (α-MT) is a blocker of SLC6A14 and is effective against pancreatic cancer in vitro and in vivo. In the present study, we tested the hypothesis that α-MT could synergize with gemcitabine in the treatment of pancreatic cancer. We investigated the effects of combination of α-MT and gemcitabine on proliferation, migration, and apoptosis in a human pancreatic cancer cell line, and examined the underlying mechanisms using 1H-NMR-based metabolomic analysis. These studies examined the intracellular metabolite profile and the extracellular metabolite profile separately. Combination of α-MT with gemcitabine elicited marked changes in a wide variety of metabolic pathways, particularly amino acid metabolism with notable alterations in pathways involving tryptophan, branched-chain amino acids, ketone bodies, and membrane phospholipids. The metabolomic profiles of untreated control cells and cells treated with gemcitabine or α-MT were distinctly separable, and the combination regimen showed a certain extent of overlap with the individual α-MT and gemcitabine groups. This represents the first study detailing the metabolomic basis of the anticancer efficacy of gemcitabine, α-MT and their combination.
研究领域:
肿瘤学
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药理学
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代谢组学
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癌症生物学
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DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2025
·
IF 6.6
Hui Ma,Na Gu,Yichuan Wu,Yanan Wang,Pu Qiu,Kefeng Wu,Jiancheng Zhao,Qi Zhao
Identifying and quantifying amino acids in complex systems of food supplements by conventional 1 H NMR spectroscopy is a challenging task. Extensive signal overlaps of a variety of amino acids in 1 H NMR spectra limit its application in the analysis of the complex amino acid systems. Triple spin echo PSYCHE (TSE-PSYCHE), a pure shift NMR analytical technique, can provide a simplified and high-resolution proton spectrum by removing the 1 H– 1 H homonuclear couplings. Hence, this TSE-PSYCHE NMR method can substantially alleviate the overlap problem so that it has a great potential for quantifying complex amino acid mixtures. Moreover, based on TSE-PSYCHE NMR we successfully quantified the components of two commercial amino acid nutrition tablets: the quantification regression analysis affords a satisfactory linearity with correlation coefficients higher than 0.9910 for all analytes, limit of detection (LOD, 0.075–0.66 mg/mL), limit of quantification (LOQ, 0.25–2.21 mg/mL), accuracy (bias %: 0.06–3.4), the recovery values between 92.38 and 109.0 %, and precision (the relative standard deviations, RSD %) at the range of 0.48–3.50. In this work, we developed a novel quantitative NMR for a global and direct analysis of amino acids of food supplement content.
研究领域:
分析化学
·
食品科学
·
代谢组学
·
核磁共振波谱学
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产品关联
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Ting Shi,Gangcheng Wu,Qingzhe Jin,Xingguo Wang
Camellia oil has become one of the most popular edible vegetable oils especially in China. It can be obtained by cold-pressing (CPE), soxhlet extraction (SE), aqueous enzymatic extraction (AEE), and supercritical carbon dioxide extraction (SC-CO 2 ), while research on their efficient identification is limited. Thus, in this study, proton nuclear magnetic resonance ( 1 H NMR) and conventional chemical analysis, respectively coupled to chemometrics, were employed to compare the camellia oils, produced by CPE, SE, AEE, and SC-CO 2 . The results showed an obviously overlapping among those four different extracted camellia oils, in both principal component analysis (PCA) and hierarchical clustering analysis (HCA), when using fatty acids as input variables. While two obtained PCA models showed good discrimination, according to the minor component compositions (α-tocopherol, squalene, stigmasterol, β-sitosterol, β-amyrin and lanosterol) and 1 H NMR spectra, respectively. Additionally, by means of variable importance for the projection (VIP) scores, less 10 dominant 1 H NMR spectra signals were screened out as detailed markers for different camellia oils classification. Therefore, 1 H NMR combined with chemometrics may be applied as an efficient technique to classify different extracted camellia oils and potentially other vegetable oils.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2016
·Vol. 27
·期 11
·2120-2126
·
IF 1.096
Dong Jian-Wei,Cai Le,Fang Yun-Shan,Duan Wei-He,Li Zhen-Jie,Ding Zhong-Tao
Radix et Rhizoma Rhei has been recognized for centuries in traditional medicine for its multiple pharmacological actions. The free anthraquinones including physcion, chrysophanol, emodin, rhein, and aloe-emodin are the main bioactive components in Radix et Rhizoma Rhei. In the present study, a fast quantitative 1H nuclear magnetic resonance (q-HNMR) method for the determination and quantitation of five free anthraquinones in Radix et Rhizoma Rhei was developed. Validation of the quantitative method was performed in terms of specificity, accuracy, precision, and stability. The results showed that the solvent acetone-d6 enabled satisfactory separation of the signals to be integrated. Five anthraquinones in Radix et Rhizoma Rhei could be quantified accurately using featured signals from 1H NMR. This work implied that q-HNMR represents a feasible alternative to high-performance liquid chromatography (HPLC)-based methods for quantitation of anthraquinones in Radix et Rhizoma Rhei and is suitable for the quality control of Radix et Rhizoma Rhei.
研究领域:
中药学
·
分析化学
·
药理学
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产品关联
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2021
·
IF 4.556
Xiuming Jiang,Denghui Yang,Guoqiang Xiang,Leqian Hu
In this work, cis and trans fatty acid (FA) contents in edible oils was determined using 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy. The comparison of 1 H NMR spectra of edible oil and cis-trans isomerized oil showed that they were different in three regions: (1) 2.880 - 2.650 ppm caused by bis-allylic protons; (2) 2.140 - 1.900 ppm due to allylic protons; and (3) 1.030 - 0.930 ppm due to methyl protons of linolenic acyl groups. The 1 H NMR signals in these regions were combined with partial least squares method to predict contents of cis/trans fatty acids in edible oils. The results showed that the predicted values were consistent with the gas chromatography-measured values and had a good linear relationship with a correlation coefficient (R 2 ) of above 0.98. This work demonstrates that 1 H NMR spectroscopy was successfully used to determine the composition of both cis and trans fatty acids in edible oils.
研究领域:
食品科学
·
分析化学
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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）