Journal of Food Measurement and Characterization
·
2021
·Vol. 15
·期 3
·2716-2726
·
IF 2.431
Qian Junqing,Zhao Changyan,Zhu Hanxiao,Tong Jun,Zhao Xiaohua,Yang Haiyan,Guo Hui
Walnut oil is endowed with a variety of physiological functions due to abundant natural compounds, and the effect of unsaturated fatty acids is crucial. In order to accurately and conveniently detect the fatty acids components and content in walnut oil, a quantitative method was developed to detect fatty acids content based on the 1 H-NMR and 13 C-NMR techniques. In addition, HPLC combined with MS was used to conduct qualitative analysis. HPLC method with an evaporative light-scattering detector was for the quantitative analysis and the fatty acids content was compared with the content from NMR. The result showed that there was no significant difference between 1 H-NMR, 13 C-NMR and HPLC (P > 0.05) and indicated that the NMR has the potential to be applied as a routine method for the analysis of fatty acids content in walnut oil.
研究领域:
分析化学
·
食品科学
·
营养学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Hui Ma,Jiancheng Zhao,Wenbo Dong,Gang Wei,Pan Zhou,Xingshun Cong,Kefeng Wu,Yingxiong Wang,Jing Liao,Qi Zhao
Nuclear magnetic resonance (NMR) technology has played a critical role in the structural characterization and signal assignments of complex drugs and natural product samples for numerous years. Despite this, data analysis remains a challenging task due to the extensive signal overlaps and homonuclear J H-H coupling multiplets present in the conventional 1 H NMR spectra. Consequently, it is necessary to introduce a general and simple strategy to achieve structural determination of complex drugs. In this study, 1D pure shift NMR spectroscopy, an effective analysis tool, is applied to analyze four complex drug compounds, including two anti-inflammatory molecules (dexamethasone and icariin), and two antibiotic compounds (erythromycin and kanamycin sulfate). Compare to the conventional NMR methods, the pure shift NMR provided only chemical shift information in one-dimension, resulting in high-resolution and clean 1 H spectra with no multiplet structure by removing the effects of homonuclear coupling. The fast assignment of the complex proton resonances in drug molecules was achieved utilizing the decoupled spectra of 1D pure shift NMR, and the short acquisition time of selective decoupling pure shift (rt-BS) NMR. The conventional proton spectra were significantly simplified through pure shift NMR, which enabled us to adequately resolve the signal overlaps and distinguish the adjacent protons. The results show that the high-resolution PSYCHE and rt-BS NMR technique have great potential for the rapid analysis and total assignments of complex compounds suffering from severe scalar coupling in a wide variety of systems.
研究领域:
药学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Yi Chen,Xiaowen Jiang,Junnan Wang,Zhengxiu Wu,Yuchen Wu,Zhonghua Ni,Hong Yi,Rongsheng Lu
The clinical challenge of high-accuracy blood glucose detection schemes is to overcome the detection error caused by the background interferences in different individuals. H2O2 as the specific product of glucose oxidation can be involved in the Fe2+/Fe3+ conversion and detected by the time-domain nuclear magnetic resonance (TD-NMR) method sensitively. But, in clinical applications, the oxidation of Fe2+ is susceptible to the complex sample substrates. In this work, we sorted out two kinds of possible interference mechanisms of Fe2+ oxidation in the NMR blood glucose detection method and proposed a feasible scheme that uses sorbitol to weaken the adverse effects of interference. We found that sorbitol-mediated Fe2+ can greatly enhance the sensitivity of the T2 value to H2O2. The chain reaction caused by sorbitol can significantly amplify the efficiency of Fe2+ oxidation at the same concentration of H2O2. Thereby, we can achieve the higher dilution multiple of serum samples to reduce the amount of interfering substances involved in the Fe2+/Fe3+ conversion. We justified the accuracy and availability of our method by successfully detecting and confirming the correlation between the T2 decrease and glucose concentration of the serum samples collected from 16 subjects. The sorbitol–Fe2+ glucose detection method with high sensitivity can be further combined with miniature NMR analyzers to satisfy the calibration requirements of glucose monitoring in diabetic patients instead of frequent medical visits.
研究领域:
医学诊断
·
生物化学
·
临床医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2018
·Vol. 23
·期 3
·554
·
IF 3.098
Qianqian Liang,Qiuying Wang,Yuan Wang,Ya-nan Wang,Jia Hao,Miaomiao Jiang
The primary metabolites in aqueous extract of mulberry (Morus albaL.) leaves were characterized by using proton nuclear magnetic resonance (1H-NMR) spectroscopy. With the convenience of resonance assignment, GABA together with the other 10 primary metabolites was simultaneously identified and quantified in one1H-NMR spectrum. In this study, external calibration curves for metabolites were employed to calculate the concentrations of interests. The proposed quantitative approach was demonstrated with good linearity (r2ranged in the interval of 0.9965–0.9999), precision, repeatability, stability (RSD values in the ranges of 0.35–4.89%, 0.77–7.13% and 0.28–2.33%, respectively) and accuracy (recovery rates from 89.2% to 118.5%). The established1H-NMR method was then successfully applied to quantify 11 primary metabolites in mulberry leaves from different geographical regions within a rapid analysis time and a simple sample preparation procedure.Keywords:quantitative1H-NMR;Morus alba;amino acids;saccharides;organic acids
研究领域:
分析化学
·
植物科学
·
代谢组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Kemeng Shi,Christian Marcus Pedersen,Zhaohui Guo,Yanqiu Li,Hongyan Zheng,Yan Qiao,Tuoping Hu,Yingxiong Wang
The tautomer distributions of d ‑fructose, a popular model compound for biorefinery , in various lower alcohols and DMSO‑ d 6 (ROHs/DMSO‑ d 6 ) mixtures at 298 K were investigated by quantitative 13 C NMR. The tautomer distributions of d ‑fructose in ethanol/DMSO‑ d 6 and methanol/DMSO‑ d 6 with different volume ratios of alcohols to DMSO‑ d 6 were also examined. For these normal alcohols (methanol, ethanol, n ‑propanol and n ‑butanol)/DMSO‑ d 6 , the tautomer distribution of d ‑fructose in methanol/DMSO‑ d 6 exhibited the shortest equilibration time (46 h) and the lowest concentration of β‑furanose (39.0%) at equilibrium. The fraction of fructofuranose (α‑furanose and β‑furanose) at equilibrium and time needed to reach equilibrium in branched chain alcohols/DMSO‑ d 6 obey the following order: 2‑propanol/DMSO‑ d 6 (62.2%, 320 h) > tert ‑butanol/DMSO‑ d 6 (61.6%, 307 h) > 2‑butanol/DMSO‑ d 6 (60.6%, 216 h) > isobutanol/DMSO‑ d 6 (57.8%, 134 h). For the diols/DMSO‑ d 6 , the time for the tautomer distribution of d ‑fructose to reach the equilibrium was found to be: 1,4‑butanediol/DMSO‑ d 6 (113 h) > 1,2‑propanediol/DMSO‑ d 6 (38 h) > ethylene glycol/DMSO‑ d 6 (36 h). For ethanol/DMSO‑ d 6 and methanol/DMSO‑ d 6 with respectively different volume ratios, the experimental results showed that the high concentration of ethanol or methanol increases the conversion rate of tautomers.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2020
·
IF 4.972
Shanshan He,Yanling Wang,Jianhua Xie,Heng Gao,Xiujiang Li,Zhibing Huang
Monascus comprises purple-red molds. Various compounds can be obtained from these species, including statins and food-safe yellow, red, and orange pigments. However, the secondary metabolite citrinin, a mycotoxin, is produced during the late stages of growth. Citrinin biosynthesis should be reduced to apply Monascus pigments safely. Fortunately, this can be achieved by the addition of flavonoids (genistein, daidzein, apigenin, and kaempferol). However, the effects of these flavonoids on other metabolites remain unknown. Here, we report a 1 H NMR-based multivariate metabolomic analysis of the effects of flavonoids on mycotoxin citrinin production by Monascus . Fifteen metabolites involved in lysine and arginine biosynthesis and alanine, aspartate, glutamate, biotin, arginine, proline, and glutathione metabolism were detected. The reduction in glutamate, aspartate, biotin, and 2-phosphoglycerate content suggested their association with the citrinin reduction mechanism. This study identifies the citrinin production pathway in Monascus and will aid in the development of citrinin-control methods.
研究领域:
微生物学
·
代谢组学
·
食品科学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
MengTing Zhu,Ting Shi,Yi Chen,ShuHan Luo,Tuo Leng,YangLing Wang,Cong Guo,MingYong Xie
A rapid method for the determination of fatty acid (FA) composition in camellia oils was developed based on the 1 H NMR technique combined with partial least squares (PLS) method. Outliers detection, LVs optimization and data pre-processing selection were explored during the model building process. The results showed the optimal models for predicting the content of C18:1, C18:2, C18:3, saturated, unsaturated, monounsaturated and polyunsaturated FA were achieved by Pareto scaling (Par) pretreatment, with correlation coefficient ( R 2 ) above 0.99, the root mean square error of estimation and prediction (RMSEE, RMSEP) lower than 0.954 and 0.947, respectively. Mean-centering (Ctr) was more suitable for the model of C16:0 and C18:0 with the best performance indicators ( R 2 ≥ 0.945, RMSEE ≤ 0.377, RMSEP ≤ 0.212). This study indicated that 1 H NMR has the potential to be applied as a rapid and routine method for the analysis of FA composition in camellia oils.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Kai Zhang,Shuwei Chen,Zhaohui Guo,Yingxiong Wang,Yan Qiao
As a renewable resource, the catalytic conversion of xylose has attracted much attention. The epimerization of xylose to lyxose is an important way to obtain the rare sugar lyxose. Current approaches to xylose epimerization encounter several challenges, including the requirement for high temperatures, the use of costly catalysts and a propensity for side reactions that favor the formation of ketoses. CaCl 2 is an environmentally friendly and naturally abundant metal salt that can act as a Lewis acid in catalytic processes. Herein, we demonstrate that CaCl 2 and Et 3 N work synergistically to achieve 68 % lyxose yield under mild conditions. Compared to conventional approaches, which often require harsh conditions or expensive catalysts, our system demonstrates a cost-effective and selective strategy. Moreover, through a combined experimental and computational approach (NMR, isotope tracing and DFT), we provide unprecedented mechanistic insights into the role of calcium complexation in facilitating epimerization. Complexation between xylose and calcium ion was confirmed by NMR titration and Diffusion Ordered NMR Spectroscopy (DOSY-NMR). Isotope experiments further demonstrated that the C1-C2 migration caused the turnover of the hydroxyl group at C2 in the presence of calcium ions. The frontier orbital analysis and deprotonation energy calculation showed that the hydroxyl group at C1 had the lowest deprotonation energy, which initiated the ring-opening process. The DFT calculations reveal that the calcium ions preferentially complex with the hydroxyl groups of xylose, thereby reducing the energy barrier for the C1 proton dissociation and facilitating the epimerization. These findings offer a new perspective on xylose epimerization with Ca-based catalyst.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Xiao-dan Shi,Ou-ye Li,Jun-yi Yin,Shao-ping Nie
Dictyophora echinovolvata is a kind of edible mushroom in the Dictyophora genus, of which polysaccharide is an important chemical substance. Herein, three polysaccharide fractions (DEP-4P, DEP-6P and DEP-8P) were prepared from water extract of D. echinovolvata using gradient ethanol precipitation method. Their chemical structures were analyzed by methylation analysis and 1D/2D NMR spectroscopy. Molecular weights were determined by multi-angle laser light scattering combined with size-exclusion chromatography (HPSEC-MALLS). HPSEC data showed that DEP-4P had the highest values of molecular weight, intrinsic viscosity and hydrodynamic radius. DEP-6P and DEP-8P had lower molecular weights, which contributed to their easily distinguished 1D and 2D NMR spectra. Methylation and NMR analysis suggested that the three fractions were linear α-(1 → 4)-glucans with α-Glc p residues linked to the backbone at C -6. Differences among the three fractions were the molar ratios of the identified glycosidic bonds. Repeating units of polysaccharides from D. echinovolvata were proposed as follows: Download : Download high-res image (60KB) Download : Download full-size image
研究领域:
生物化学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Chemistry Frontiers
·
2018
·Vol. 2
·期 6
·1201-1206
·
IF 0
Jie Hu,Kai Cheng,Qiong Wu,Dashuang Ding,Conggang Li,Zhen Li
In this study, a dual-channel probe of FlE based on flavonoid derivatives is reported, which can yield “turn-on” signals of both fluorometry and 19F nuclear magnetic resonance in response to the presence of esterase. Upon the addition of esterase, FlE could convert into Fl, possessing the ESIPT effect. As a result, the fluorescence intensity was significantly enhanced and peaked at 510 nm, accompanying a change in the fluorescence of solution from nonluminous to strong green. Moreover, as determined by 19F NMR, the signal could apparently shift from δF −111.57 to −111.69 ppm. Due to the combination of these two detection approaches having good sensitivity, high selectivity, and real-time detection, FlE has been successfully applied to confocal fluorescence imaging for the detection of esterase in cells, which consistent with the 19F NMR test results in some sense.
研究领域:
生物化学
·
分析化学
·
细胞生物学
✓ 已验证
产品关联
DOI
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2022
·
IF 3.571
Jing Jiang,Zhao-liang Hu,Hamza Boucetta,Jia-ming Liu,Min Song,Tai-jun Hang,Yu-ting Lu
Flumazenil is an imidazobenzodiazepine derivative that antagonizes the actions of benzodiazepines . The degradation pathway elucidation plays an important role in the drug quality control. In this work, a reliable LC-Q-TOF/MS method was developed to separate and identify the degradation products of flumazenil generated in the stress testing conducted according to the ICH Q1A(R2) guideline. Fifteen degradation products were detected in total including three reported impurities and twelve unknown impurities. Based on the chromatographic and mass spectrometric data acquired, the structures of all the degradation products were identified. Besides, two major degradants were synthetized and further confirmed by NMR. The degradation pathways of flumazenil were elucidated, and the degradation characteristics of benzodiazepines were also discussed. The obtained results are of both great importance for the quality control of flumazenil and good reference for the degradation study of other benzodiazepines.
研究领域:
药物化学
·
分析化学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Yu Kang,Yuan Zheng,Zi-Yi Zhang,Bin Li,Yao-Yang Liu,Yun-Hong Xie,Zhong-Feng Li,Xiao-Yan Tang,Jing Chen,Li Wang,Chao Xu
In situ characterization of coordination species and their evolution are crucial for effective lanthanide separation and recycling. Current technical approaches often operate under constrained conditions, requiring complex equipment, experimental setups, and sometimes intricate data interpretation. Herein, we demonstrate that carbon NMR titrations offer a valuable approach for in situ coordination analysis of lanthanides, particularly for highly fused preorganized ligands that offer more NMR-active carbons than traditional proton NMR. Two representative ligands of both lipophilic and hydrophilic in nature were investigated, and the resulting carbon NMR titration data were analyzed. Comparisons with IR and single-crystal data showed that NMR provided insights not only into the evolution of coordination species but also into changes in the electron distribution during complex formation. Additionally, we discussed inconsistencies between atomic charge populations obtained from carbon NMR and those from Mulliken and Hirshfeld calculations. With advancements in NMR technology and the availability of higher-field NMR instruments, we believe NMR titrations will play an increasingly significant role in unravelling the complex solution coordination chemistry of f-block elements.
研究领域:
化学
·
配位化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）