FOOD CHEMISTRY
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2022
·
IF 9.231
Xinxin Zheng,Qing Huang
Astaxanthin (AST) is a natural antioxidant and has been widely applied as a food supplement. While astaxanthin has many isomers, there are few studies comparing its physicochemical properties. In this work, we were concerned about their antioxidant activities against external oxidative stresses, and specifically, the singlet oxygen ( 1 O 2 ) quenching capacities of the representative optical and geometric isomers of astaxanthin were examined. Methylene blue (MB) was used as the photosensitizer to produce 1 O 2 , and 1,3-diphenylisobenzofuran (DPBF) was used to probe 1 O 2 . Our results showed that the 1 O 2 quenching capacities of the optical isomers, including 3 S ,3 ′S , 3 R ,3 ′S , and 3 R ,3 ′R all- trans -astaxanthin, are identical. In contrast, the 1 O 2 quenching capacity of cis -astaxanthin is higher than that of all- trans -astaxanthin. As such, this work provides an effective spectroscopic approach to assessing the antioxidant activities of various forms of astaxanthin against singlet oxygen, and demonstrates the remarkable difference among the geometric isomers.
研究领域:
食品科学
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生物化学
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Yixin Kuang,Suxin Zhou,Cheng Mao,Xiaoying Feng,Juan Zheng,Gangfeng Ouyang
High-resolution separation of numerous isomers is highly desirable for their high-quality analysis, yet challenging, which puts forward high requirements on the precise design of stationary phase. Herein, flexible 4- tert -butylcalix[n]arenes (TBCx[n]s) with different cavities have been intelligently integrated with in-situ grown UiO-66 coatings, to investigate their separation efficiencies for alkane and substituted benzene isomers. The modifications of UiO-66 with TBCx[n]s have made up for the deficiency of UiO-66 on the separation of ethylbenzene and styrene. The effects of TBCx[n]s on the separation performance of UiO-66@TBCx[n]s have demonstrated distinct regularities, i.e., the effects of TBCx[6] are superior to those of TBCx[8], while the TBCx[4] is the least effective. The baseline separation of all analytes has been achieved by the UiO-66@TBCx[6] column with enhanced selectivity and improved separation resolution (Rs). For the six groups of isomers that are most difficult to separate, the corresponding selectivity and Rs are greater than 1.09 and 5.48, respectively, confirming the outstanding separation performance of the UiO-66@TBCx[6] column and the feasibility of integrating soft supramolecule and rigid MOF.
研究领域:
化学工程
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材料科学
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分析化学
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
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2017
·Vol. 41
·期 6
·1385-1394
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IF 2.557
Jun-Hui Zhang,Sheng-Ming Xie,Bang-Jin Wang,Pin-Gang He,Li-Ming Yuan
Porous organic cages composed of discrete cage molecules have attracted considerable recent attention as gas adsorption materials and separation media. In this study, we report a homochiral porous organic cage CC5 with a large cavity and pore windows as a novel stationary phase for high-resolution gas chromatographic separations. The capillary column was prepared by a static coating method. A large number of racemic compounds have been resolved on the coated capillary column, including derivatized amino acids, alcohols, alcohol amines, esters, ethers, ketones, and epoxides. It is interesting that the CC5-coated capillary column exhibits significant chiral recognition complementarity to a commercial β-DEX 120 column and a previously reported homochiral porous organic cage CC3-R-coated column, which could expand the range of the analytes amenable to separation on porous organic cage-based capillary columns. Moreover, the fabricated column also shows excellent selectivity for the separation of positional isomers, including the challenging ethylbenzene and xylene isomers. Experimental results demonstrate an excellent separation performance and stability of the CC5-coated column, making it promising for gas chromatography applications.
研究领域:
化学
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分析化学
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PubMed
高影响因子
Scientific Reports
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2016
·Vol. 6
·期 1
·1-9
·
IF 5.228
Yang Hongmei,Shi Lei,Zhuang Xiaoyu,Su Rui,Wan Debin,Song Fengrui,Li Jinying,Liu Shuying
It remains particularly difficult for gaining unambiguous information on anomer, linkage and position isomers of oligosaccharides using conventional mass spectrometry (MS) methods. In our laboratory, an ion mobility (IM) shift strategy was employed to improve confidence in the identification of structurally closely related disaccharide and monosaccharide isomers using IMMS. Higher separation between structural isomers was achieved using 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization in comparison with phenylhydrazine (PHN) derivatization. Furthermore, the combination of pre-IM fragmentation of PMP derivatives provided sufficient resolution to separate the isomers not resolved in the IMMS. To chart the structural variation observed in IMMS, the collision cross sections (CCSs) for the corresponding ions were measured. We analyzed nine disaccharide and three monosaccharide isomers that differ in composition, linkages, or configuration. Our data show that coexisting carbohydrate isomers can be identified by the PMP labeling technique in conjunction with ion-mobility separation and tandem mass spectrometry. The practical application of this rapid and effective method that requires only small amounts of sample is demonstrated by the successful analysis of water-soluble ginseng extract. This demonstrated the potential of this method to measure a variety of heterogeneous sample mixtures, which may have an important impact on the field of glycomics.
研究领域:
分析化学
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糖组学
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生物医学
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2016
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IF 3.926
Xiaohong Yang,Changxia Li,Meiling Qi,Liangti Qu
This work presents the separation performance of graphene-ZIF8 (G-Z) composite material as stationary phase for capillary gas chromatography (GC). The G-Z stationary phase achieved high column efficiency of 5000 plates/m determined by n -dodecane ( k = 1.22) at 120 °C and showed weakly polar nature. Importantly, it exhibited high selectivity and resolving capability for branched alkane isomers and aromatic positional isomers, showing clear advantages over the reported neat graphene and ZIF8. In addition, it attained high resolution for geometric cis -/ trans -isomers. The G-Z column exhibited good column thermal stability up to 300 °C and column repeatability with RSD values of retention times in the range of 0.01–0.19% for intra-day, 0.05–0.88% for inter-day and 0.66–5.6% for between-column, respectively, Moreover, the G-Z column was employed for the determination of minor impurity isomers in real reagent samples, which demonstrates its promising potential in GC applications .
研究领域:
分析化学
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材料科学
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PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2022
·
IF 4.598
Ning Liu,Baozhu Yang,Zheng-Zhi Yin,Wenrong Cai,Junyao Li,Yong Kong
Chiral metal–organic framework (ZIF-8) was successfully prepared through a two-step electrodepostion method by using l -histidine ( l -His) as the chiral source, and the resultant chiral ZIF-8 ( l -His-ZIF-8) was used for enantiodiscrimination of the isomers of tyrosine (Tyr) and tryptophan (Trp). Although the isomers of both Tyr and Trp could be well discriminated by the l -His-ZIF-8 modified electrode, they displayed opposite voltammetric behaviors on the differential pulse voltammograms (I D-Tyr > I L-Tyr ; I D-Trp < I L-Trp ), which could be explained by density functional theory (DFT). Finally, both the pH and the electrodeposition time were optimized to obtain the highest recognition efficiency of the l -His-ZIF-8 modified electrode toward the isomers of Tyr and Trp.
研究领域:
生物化学
·
分析化学
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DOI
高影响因子
TALANTA
·
2021
·
IF 6.057
Danni Jiang,Jia Chen,Ming Guan,Hongdeng Qiu
In this work, 1-vinyl-3-octadecylimidazolium bromide ionic liquids ([C 18 VIm]Br) and their derived carbon dots (ImC 18 CDs) were prepared, [C 18 VIm]Br and ImC 18 CDs were grafted on the silica to obtain Sil-ImC 18 and Sil-ImC 18 CDs, respectively, and they were also co-grafted on silica which named Sil-ImC 18 /CDs. Compared with Sil-ImC 18 and Sil-ImC 18 CDs columns, Sil-ImC 18 /CDs column exhibited enhanced selectivity for separation of tetracyclic/tricyclic polycyclic aromatic hydrocarbon (PAH) isomers, and butylbenzene isomers in reversed-phase liquid chromatography, which may be due to the synergistic effect between ImC 18 CDs and [C 18 VIm]Br, the π-π interaction between imidazolium and analytes, etc. Meanwhile, the retention behavior of Sil-ImC 18 /CDs was further evaluated and compared with the commercial C 18 column using different classes of analytes, including standard test mixtures of Tanaka, Engelhardt, SRM869b, SRM870. The results demonstrated that co-grafted column exhibited superior separation performance. And this column was applied to determine the contents of calycosin-7-glucoside, ononin , calycosin and formononetin in the extract of Radix Astragali, which were found that the concentration was 0.25 mg mL −1 , 0.15 mg mL −1 , 0.13 mg mL −1 and 0.30 mg mL −1 , respectively.
研究领域:
分析化学
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材料科学
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PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2023
·
IF 4.8
Cai-Fang Liu,Xiao-Yan Ran,Cheng Liu,Yu-lan Zhu,Yan-Rui Lu,Yu-Ping Yang,Bang-Jin Wang,Jun-Hui Zhang,Sheng-Ming Xie,Li-Ming Yuan:
Chiral metal–organic frameworks, an emerging type of chiral porous materials, possess many outstanding characteristics such as high surface area, tunable pore sizes, and good chemical stability. Herein, we prepared a chiral [Zn 2 (D-Cam) 2 (4,4′-bpy)] n @SiO 2 core–shell composite on the SiO 2 -NH 2 microspheres by an in-situ growth method. The prepared [Zn 2 (D-Cam) 2 (4,4′-bpy)] n @SiO 2 -packed column exhibited high-resolution separation of racemic compounds and positional isomers at a low column backpressure (9–12 bar). Twelve pairs of enantiomers including alcohols, amines, epoxides, ketones, and esters were well resolved with sharp peak shapes on the [Zn 2 (D-Cam) 2 (4,4́-bpy)] n @SiO 2 chromatographic column. Compared the separation performance of [Zn 2 (D-Cam) 2 (4,4́-bpy)] n @SiO 2 -packed column and two chromatographic columns (commercial Chiralpak AD-H column and as-prepared SiO 2 -NH 2 column), the [Zn 2 (D-Cam) 2 (4,4′-bpy)] n -packed column and the commercial Chiralpak AD-H column have a good complementarity in chiral separation, and it also offered better separation performance compared to the SiO 2 -NH 2 column for separating positional isomers. The effects of column temperature and analyte mass on the HPLC separation were investigated. Additionally, the [Zn 2 (D-Cam) 2 (4,4́-bpy)] n @SiO 2 packed column has good repeatability and stability for HPLC separation of enantiomers and positional isomers. The relatvive standard deviations (RSDs) for repeated separations of 2,2,2-trifluoro-1-(9-anthryl)ethanol and o , m , p -bromoaniline were less than 0.8 % and 1.2 % for the retention time and peak area, respectively. After continuous use for one month, the RSDs for the retention time and peak area of them were in the range of 1.1–1.3 % and 1.5–1.8 % (inter-day and intra-day, n = 5), respectively. This work also indicates that the chiral MOFs@SiO 2 composites are promising for HPLC separation.
研究领域:
分析化学
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材料科学
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色谱技术
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Huimin Deng,Ying Wang,Jinbang Wang,Shanshan Liu,Yuan Ji,Ziyan Fan,Zhonghao Li,Fei Yang,Zhaoyang Bian,Gangling Tang
N′ -nitrosonornicotine (NNN) is one of the most prevalent and toxic tobacco-specific nitrosoamines. A chiral center at its 2′-position results in R and S enantiomers, the partial double bond character of the N N = O group also results in E and Z isomers, therefore, NNN can form a total of four absolute configurations ( E -( R )-NNN, E -( S )-NNN, Z -( R )-NNN, and Z -( S )-NNN). This study investigated the resolution of R/S enantiomers and E/Z isomers of NNN by supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS). The baseline separation of E / Z -( R,S )-NNN isomers/enantiomers was accomplished through the optimization of chiral columns and co-solvents. Due to the lack of single standard of E / Z isomers, only R -NNN (sum of E -( R )-NNN and Z -( R )-NNN) and S -NNN (sum of E -( S )-NNN and Z -( S )-NNN) were further examined. Through the comprehensive optimization of SFC-MS/MS conditions, R -NNN and S -NNN were separated with a run time of 5 min, the developed method was validated, and its applicability to the determination of NNN enantiomers in burley tobacco samples was demonstrated. This study could be applied to preparative separation of single enantiomer and/or isomer of NNN, and could provide potential benefits to biologic activity studies on these enantiomers and isomers.
研究领域:
化学分析
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毒理学
·
烟草研究
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Sisi He,Yiyi Liu,Chaoxian Chi,Dongdong Zhou,Chuan-Fan Ding,Xucong Lin,Jiabin Wang,Fangling Wu
The differentiation of 3-AminoPyrrolidine (3AP) and its derivative isomers is significant due to their use as intermediates in drug synthesis. However, the separation of these isomers, which exhibit both chiral and positional isomerism, has consistently posed challenges. In this study, an efficient analytical method was developed to discrimination between the four isomers of R/S-I/N-Boc-3-AminoPyrrolidine (R/S-l/N-Boc-3AP) and four groups of derived chiral isomers, namely R/S-N-Methyl-3-AminoPyrrolidine (R/S-N-Me-3AP), R/S-N-Ethyl-3-AminoPyrrolidine (R/S-N-Et-3AP), R/S-1-Bzl-3-AminoPyrrolidine (R/S-1-Bzl-3AP), and R/S-1-Cbz-3-AminoPyrrolidine (R/S-1-Cbz-3AP). The discrimination was achieved by utilizing natamycin (Nat) as a differentiation agent and 2/3/4-aminobenzenesulphonic acid (2/3/4-ABSA) as ligand. The facile discrimination of the four positional isomers of R/S-1-Boc-3AP and R/S-N-Boc-3AP was achieved using ion mobility spectrometry (IMS) based on their formed diastereomeric complexes [Nat + (Boc-3AP) 2 + (2-ABSA) 2 + H] + . The isomers were also studied via tandem mass spectrometry (MS/MS) using the formed ternary complexes, different fragment ions were observed for l-Boc-3AP and N-Boc-3AP, but the R/S enantiomers cannot be discriminated either. In addition, the enantiomers R/S-l-Bzl-3AP and R/S-l-Cbz-3AP were differentiated based on mobility using [Nat + (R/S-l-Bzl-3AP) + (3-ABSA) 2 + H] + and [Nat + (R/S-l-Cbz-3AP) + 2-ABSA + H] + ; however for the small enantiomeric molecules of R/S-N-Me-3AP and R/S-N-Et-3AP, chiral discrimination was not achieved via the ternary complexes of Nat + R/S-N-Me-3AP-ABSA and Nat + R/S-N-Et-3AP-ABSA. Importantly, the separation was greatly improved by the coordinated alkali metal ions, where the separation resolution (R p-p ) increased with the radius of the metal ions. Finally, quantitative analysis and method validation were carried out for the four Boc-3AP isomers using both MS/MS and IMS-MS. Overall, the proposed method opens possibilities for the rapid discrimination and quantification of isomers exhibiting both chiral and positional isomerism in MS/MS and IMS-MS analyses.
研究领域:
分析化学
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药物化学
·
质谱分析
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DOI
高影响因子
PEST MANAGEMENT SCIENCE
·
2025
·
IF 3.8
Haoming Guo,Nan Xiao,Zhixuan Wang,Yabo Liang,Xueke Liu,Peng Wang,Donghui Liu
BACKGROUND Indoxacarb, a type of chiral pesticide, is used to control Lepidoptera insects. Most studies had focused on the environmental behavior and selective toxicity of indoxacarb enantiomers, and the mechanism behind its selective biological activity against target organisms is not well understood. RESULTS Spodoptera frugiperda was selected as the target insect. The lethal concentrations (96 h) of indoxacarb enantiomers on S. frugiperda were 2.61 mg/kg ( S -indoxacarb) and 463.52 mg/kg ( R -indoxacarb). S -Indoxacarb resulted in stronger oxidative damage to S. frugiperda than R -indoxacarb, and catalase and malondialdehyde were upregulated by 40.46% and 68.64% respectively after treatment with S -indoxacarb. Furthermore, cytochrome P450 and carboxylesterase were activated by S -indoxacarb, increasing by 39.62% and 63.68% respectively. Decarbomethoxyllated JW062 (DCJW), a metabolite of indoxacarb, has insecticidal activity. The concentration of DCJW in the S -indoxacarb treatment group was 2.73 times that in the R -indoxacarb treatment group. Molecular docking results demonstrated that S -indoxacarb could spontaneously bind to metabolic enzymes and be metabolized. CONCLUSIONS Enantiomeric bioactivity of indoxacarb enantiomers against on S. frugiperda was observed. S -Indoxacarb demonstrated remarkable insecticidal efficacy. Upon ingestion by S. frugiperda , it induced oxidative damage. Furthermore, S -indoxacarb was metabolized to DCJW, which has a significant role in its insecticidal properties. The selective bioactivity of indoxacarb enantiomers in S. frugiperda might be attributed to the enantiomeric metabolites. These findings offer a new perspective on the selective mechanisms of chiral pesticides. © 2025 Society of Chemical Industry.
研究领域:
昆虫学
·
农药科学
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生物化学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2025
·
IF 6
Yuling Li,Weiran Zhao,Xiang Xiang,YunLei Hu,Xiaoqiang Zhang,Wenjian Sun,Xiaoxuan Liu
Background Perturbed lipid metabolism in cellular environment plays an essential role in the progression of peripheral neuropathy, such as Charcot-Marie-Tooth disease type 1A (CMT1A). Current deep-profiling of lipidome still has certain limitations for high-throughput analysis of clinical samples, such as low sensitivity, extensive requirement of instrument modification, technician-dependent pretreatment and lack of method-adapted data-processing software. Results Herein, a new generation aza-Prilezhaev aziridination (APA) reagent has been designed for coupling with high-resolution liquid chromatography mass spectrometry (LC-MS) to conduct comprehensive untargeted deep lipidomics of CMT1A disease. It facilitates large-scale lipid structural annotations over a wide polarity range in a single run with high-sensitivity. With the developed method, an extensive library containing information on retention time, m / z , and MS/MS down to C=C location levels for 393 unsaturated lipids of CMT1A was created. Significant disease-related differences in C=C isomer profiles were observed from the comparison of plasma between CMT1A patients (N=9) and controls (N=8). Specifically, 40 different lipids were identified, predominantly comprising n-6, n-7, and n-9 C=C positional isomers. Significance This innovative methodology would offer substantial potential to enhance diagnosis and therapeutic strategies for CMT1A and other diseases based on lipid isomerization information.
研究领域:
神经病学
·
脂质组学
·
代谢组学
·
分子诊断学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）