ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Anqi He,Lei Ni,Hui Fu,Xiu Zhang,Zhen-Qiang Yu,Jun Song,Limin Yang,Yizhuang Xu,Yukihiro Ozaki,Isao Noda
When diffusion coefficients of different components in a mixture are similar, NMR spectra of pure individual components are difficult to be obtained via a diffusion-ordered spectroscopy (DOSY) experiment. Two-dimensional correlation spectroscopy (2D-COS) is used to analyze the data from the DOSY experiment. Through the properties of the systematic absence of cross-peak (SACP) in the 2D asynchronous spectra, spectra of pure components can be obtained even if their diffusion coefficients are similar. However, fluctuations in peak-position and peak-width are often unavoidable in NMR spectra, which makes SACPs unrecognizable. To address the problem, a 2D quotient spectrum is used to identify the masked SACPs. However, undesirable interference peaks due to the fluctuations in peak-position and peak-width are still present when we extract a spectrum of a component by slicing the 2D asynchronous spectrum across the SACP. A genetic algorithm (GA) is used to select a suitable subset of spectra where the diversities of peak-position and peak-width are significantly reduced. Then, we used the selected spectra to construct a refined 2D asynchronous spectrum so that the spectra of pure components with significant attenuated interference can be obtained. The above approach has been proven to be effective on a model system and a real-world example, demonstrating that 2D-COS possesses a bright perspective in the analysis of the bilinear data from DOSY experiments.
✓ 已验证
产品关联
DOI
PubMed
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.
✓ 已验证
产品关联
DOI
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Greenhouse Gas Control
·
2014
·
IF 3.821
Chao Guo,Shaoyun Chen,Yongchun Zhang
Quantitative 13 C nuclear magnetic resonance (NMR) spectroscopy was used to study carbon dioxide (CO 2 ) absorption and desorption, at 313 and 393 K, respectively, from 30 wt% aqueous 2-(2-aminoethylamine)ethanol (AEEA), 30 wt% 2-amino-2-methyl-1-propanol (AMP) and 20 wt% AEEA + 10 wt% AMP solutions. The 13 C NMR results indicate that the main AEEA species are free amine, protonated amine, primary carbamate and secondary carbamate, and the main AMP species are free amine and protonated amine. There is no evident indication that dicarbamate species of AEEA and carbamate of AMP are formed. When AEEA absorbs CO 2 , the formation of AEEA carbamate on primary amine is comparatively faster than that on secondary amine. During the CO 2 desorption process, the AEEA carbamate on secondary amine is produced by an endothermic reaction, which reduces the overall efficiency of desorption. Six cycles of absorption–desorption tests are performed to measure the feasibility of regenerated amine solutions for reuse and the absorption amount of them remains essentially constant during the second to the sixth absorption–desorption experiments. Compared with pure AEEA solution, the recyclability of blended amines, AEEA + AMP, improves while the mol CO 2 /mol amine (CO 2 loading) of the blended amines decreases.
研究领域:
化学工程
·
环境化学
·
碳捕集与封存（CCS）
·
物理化学
·
核磁共振（NMR）波谱学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yanan Yang,Yu Zhang,Hong Zheng,Baichao Zhang,Qi Zuo,Kaiyue Fan
A key challenge in trace heavy metals removal from drinking water by adsorption technology is to achieve high adsorption capacity and rapid uptake speed of adsorbent. Herein, we report a functionalized double modified covalent organic framework (DMTD–COF–SH) bearing high-density sulfur and nitrogen chelating groups provided simultaneously by 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and 1,2-ethanedithiol, which was prepared via a facile one-pot thiol-ene “click” reaction. PXRD , FTIR, XPS, SEM, BET and 13 C MAS NMR confirmed their successful graft, and DMTD was found to be more easily grafted on the COF surface layer than 1,2-ethanedithiol. The as-prepared DMTD–COF–SH showed remarkable adsorption capacity and ultrafast uptake dynamics to trace heavy metals owing to the synergistic effects resulting from densely populated sulfur and nitrogen chelating groups within ordered COF mesopores and at the COF surface. On the basis of the drinking water treatment units standard NSF/ANSI 53–2020, when the adsorbent dosage was 10 mg/30 mL and 20 mg L −1 calcium ions coexisted, the lead concentration decreased from initial 150 μg L −1 to 2.89 μg L −1 within 10 s, far below the allowable limit of world health organization (WHO) drinking water standard (10 μg L −1 ), and the maximum adsorption capacity meeting the standard attained 14.22 mg g −1 . The adsorbent also exhibited excellent stability, wide applicable pH range and outstanding adsorption performance for coexisting trace lead, mercury, cadmium, chromium (VI) and copper in tap water, indicating that the DMTD–COF–SH material has excellent application prospect for trace heavy metals removal from drinking water.
研究领域:
环境科学
·
材料科学
·
水处理
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2017
·Vol. 183
·期 4
·1488-1502
·
IF 1.751
Wang Liming,Chen Yan
Cycloastragenol (CA), an exclusive telomerase activator, was derived from the Astragali Radix which is widely distributed in Turkey. Until now, there is no report to produce CA with effective and environment-friendly methods. Biotransformation is considered to be a promising technology. Thus, the present study was aimed to establish a biotransformation technology that could efficiently produce CA. In this paper, a microorganism, LG-502, was used to successfully transform astragaloside IV (ASI) to CA by analysis of thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The phylogenetic analysis of the 16S rRNA indicated that this strain belongs to Bacillus sp. Three metabolites were separated during the fermentation and characterized to be cyclogaleginoside B, CA, and 20 R , 24 S -epoxy-6 α , 16 β , 25-trihydroxy-9, 19-cycloartan-3-one based on NMR and MS spectroscopic analyses. The conversion rate of ASI and yield rate of CA were achieved as high as 89 and 84%, respectively, under optimized conditions. Enzymatic analysis showed that the glycosidases were mainly located inside the bacterial body, and the activities of glucosidases were much higher than the xylosidases under the experimental conditions. This study provides a feasible, effective, and eco-friendly way to prepare CA from ASI, which might greatly contribute to the applications of ASI.
研究领域:
药学
·
生物技术
·
微生物学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Macromolecular Science Part A-Pure and Applied Chemistry
·
2014
·
IF 0.74
Yunyan Xue,Dandan Ma,Tianzhu Zhang,Siyan Lin,Shengnan Shao,Ning Gu
In this study, a series of comb-like methoxy polyethylene glycol (MPEG) functionalized polyurethanes (PUs) (PU–g–MPEG) were successfully prepared via ‘click’ chemistry and polyaddition reaction. The copper catalyzed Huisgen 1,3-dipolar cycloaddition was firstly carried out between 3,5-bis(hydroxymethyl)-1-propargyloxybenzene (PBM) and methoxy polyethylene glycol azide (MPEG–N3) to obtain MPEGylated diol PBM (MPEG–PBM). Then, the comb-like PUs having MPEG located on the backbones (PU–g–MPEG) were synthesized through the polyaddition of MPEGylated diol PBM and hexamethylene diisocyanate (HDI). Fourier transform infrared (FTIR), 1H NMR spectroscopy, size exclusion chromatography (SEC), and thermo gravimetric analyses (TGA) were used to characterize these synthesized MPEG-functionalized comb-like PUs (PU–g–MPEG). Compared with PU without MPEG grafts, PU–g–MPEG show a better wettability.
研究领域:
高分子化学
·
材料科学
·
有机合成
·
表面化学
✓ 已验证
DOI
高影响因子
Journal of Pharmaceutical Innovation
·
2025
·Vol. 20
·期 6
·1-17
·
IF 2.7
Lin Jinsheng,Wu Qilin,Liu Xueyang,Cao Renjian,Yong Qiyun,Li Dan,Chen Wenbin,Li Min,Shen Weiyang
Purpose This study intended to investigate two unknown impurity peaks (DP-1 and DP-2, at 0.29% and 0.20%, respectively) observed during the stability testing of brexpiprazole drug substance, which exceeded the unspecified impurity threshold (≤ 0.10%) and triggered an out-of-specification (OOS) investigation in a GMP environment. The objectives are to identify their structures, determine whether they are true impurities or artificial degradants, and establish appropriate control procedures for the pharmaceutical analysis of brexpiprazole. Methods The impurities were initially characterized using LC-UV/PDA high-resolution MS n ( n = 1 to 3), which identified DP-1 as an isomer of brexpiprazole and DP-2 as a dimer. Further structural elucidation of DP-1 was performed using semi-preparative HPLC and 1D/2D NMR spectroscopy. Forced degradation studies were conducted under photolytic conditions to confirm the formation of DP-1 and DP-2, with freshly prepared solutions kept in the dark as controls. Results DP-1 and DP-2 are both photo-degradants of brexpiprazole in solution. DP-1 is confirmed as an intramolecular [2 + 2] cycloaddition product of brexpiprazole, which is a novel and unreported impurity found in the product of brexpiprazole. DP-2 is identified as an intermolecular [2 + 2] cycloaddition product and consistent with a prior literature [ 1 ]. Both impurities formed only under light exposure and were absent in the light-protected samples, confirming their photodegradation origin rather than inherent impurities. Conclusion Both DP-1 and DP-2 are photo-induced degradants of brexpiprazole, rather than real impurities. These findings enhance understanding of brexpiprazole’s degradation chemistry and emphasize the need for light-protected sample preparation to prevent artifactual peaks in pharmaceutical analysis of brexpiprazole drug substance and its formulations.
研究领域:
药物化学
·
分析化学
·
药物稳定性
·
杂质谱分析
·
质谱分析
·
核磁共振（NMR）
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Zonghui Zhang,Lili Hu,Haizheng Tao,Jinjun Ren
Glassy precursors in the Li 1+ x Ga x Ge 2- x P 3 O 12 system are prepared by melting and casting. The glasses are annealed at the crystallization peak temperatures to obtain glass ceramics with Na-superionic conducting structure. The ionic conductivity can be significantly increased by substituting Ge with Ga and Li. The highest ionic conductivity of the glass ceramics is 9.74 × 10 −5 S cm −1 at 20 °C. Multiple magic angle spinning nuclear magnetic resonance (MAS NMR) techniques are used to characterize the structural transitions from glasses to their glass ceramic counterparts. 71 Ga and 31 P MAS NMR spectra have shown that the local structures of the glasses are distinctly modified after crystallization. The second coordinated shells of Ga 3+ ions are consisted of phosphorus in both glasses and glass ceramics although their coordination numbers change. The glassy precursors show homonuclear segregations such as P-O-P and Ge-O-Ge linkages. However, the glass ceramics are homogeneous, in which per phosphorus tetrahedron connects with total four Ga and Ge, forming four different phosphorus species (Q 0 (4-n)Ge, nGa (n = 0, 1, 2, and 3)). A random distribution model can be used to quantitatively predict the population of every Q 0 (4-n)Ge, nGa species, if the compositions are known. A correlation between local structure and ionic conductivity is proposed.
研究领域:
材料科学
·
固体化学
·
电化学
·
核磁共振光谱学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 16
·6063
·
IF 4.6
Yali Guo,Bing Wang,Lifei Gu,Guo Yin,Shuhong Wang,Meifang Li,Lijun Wang,Xie-An Yu,Tiejie Wang
The fraud phenomenon is currently widespread in the traditional Chinese medicine Radix Astragali (RA) market, especially where high-quality RA is substituted with low-quality RA. In this case, focused on polysaccharides from RA, the classification models were established for discrimination of RA from different growth patterns, origins, species, and growth years. 1H Nuclear Magnetic Resonance (H1-NMR) was used to establish the spectroscopy of polysaccharides from RA, which were used to distinguish RA via chemical pattern recognition methods. Specifically, orthogonal partial least squares discriminant analysis (OPLS-DA) and linear discriminant analysis (LDA) were used to successfully establish the classification models for RA from different growth patterns, origins, species, and growth years. The satisfactory parameters and high accuracy of internal and external verification of each model exhibited the reliable and good prediction ability of the developed models. In addition, the polysaccharide content and immunological activity were also tested, which was evaluated by the phagocytic activity of RAW 264.7. And the result showed that growth patterns and origins significantly affected the quality of RA. However, there was no significant difference in the aspects of origins and growth years. Accordingly, the developed strategy combined with chemical information, biological activity, and multivariate statistical method can provide new insight for the quality evaluation of traditional Chinese medicine.Keywords:Radix Astragali;immunomodulatory activity;polysaccharide content;chemical pattern recognition;quality evaluation
✓ 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）