ANALYTICAL CHEMISTRY
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2022
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IF 8.008
Fangling Wu,Xishi Wu,Chaoxian Chi,Chuan-Fan Ding
Fatty acids play a pivotal role in biological processes and have many isomers, particularly at the C═C position, that influence their biological function. Distinguishing between isomers is crucial to investigating their role in health and disease. However, separating the isomers poses a significant analytical challenge. In this study, we developed a simple and rapid strategy combining ion mobility spectrometry and theoretical chemical calculations to differentiate and quantify the C═C positional isomers in 2-/3-butenoic acid (BA), 2-/3-/4-pentenoic acid (PA), and 2-/3-/5-hexenoic acid (HA). C═C positional isomerism was mobility-differentiated by simple complexation with crown ethers (12C4, 15C5, and 18C6) and divalent metal ions (Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+, Sr2+, and Ba2+), that is, converting C═C positional isomers with small structural differences into complexes with large structural differences through the interaction with metal ions and crown ethers. Metallized isomers were formed but could not be differentiated due to their complex and overlapping extracted ion mobiliograms (EIMs). Binary crown ether–isomer complexes were not observed, indicating that C═C positional isomers could not be separated by simple mixing with crown ethers. However, significant EIM differences were obtained for the formed ternary complexes, allowing baseline separation for the isomers. Notably, all crown ethers and metal ions have a separation effect with the isomers, with a calculated separation resolution (Rp–p) of 0.07–2.44. Theoretical chemical calculations were performed to provide in-depth structural information for the complexes and explain the separation principle. Theoretical conformational space showed that the divalent metal ions act as a bridge connecting the crown ether and the isomer. Additionally, the ternary complex becomes more compact as the distance between C═C and −COOH increases. Theoretical results can reflect the features of mobility experiments, with relative errors between the experiment collision cross-section (CCS) and theoretical CCS of no more than ±8.06%. This method was also evaluated in terms of quantification, accuracy, and precision repeatability. Overall, this study establishes that the crown ether–metal ion pair can function as a robust unit for differentiating C═C positional isomerism.
研究领域:
分析化学
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生物化学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2020
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IF 5.977
Xiaoping Zhang,Xiang Ren,Konstantin Chingin,Jiaquan Xu,Xin Yan,Huanwen Chen
We present an approach for the elucidation of C=C bond position and cis/trans isomers, which is achieved by the reaction of ambient water radical cations and double bonds, followed by the fragmentation of epoxide radical cations to generate diagnostic ions in tandem mass spectrometry . Hexenol double bond positional isomers and cis/trans isomers which exhibit different properties and biological functions are characterized as a proof of concept. The merits of the approach include the simplicity of experimental setup, rapid derivatization (within seconds), the obviation of organic solvents , as well as easy spectral interpretation.
研究领域:
分析化学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Nature Communications
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2020
·Vol. 11
·期 1
·1-11
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IF 12.121
Cao Wenbo,Cheng Simin,Yang Jing,Feng Jiaxin,Zhang Wenpeng,Li Zishuai,Chen Qinhua,Xia Yu,Ouyang Zheng,Ma Xiaoxiao
Lipids play a pivotal role in biological processes and lipid analysis by mass spectrometry (MS) has significantly advanced lipidomic studies. While the structure specificity of lipid analysis proves to be critical for studying the biological functions of lipids, current mainstream methods for large-scale lipid analysis can only identify the lipid classes and fatty acyl chains, leaving the C=C location and sn -position unidentified. In this study, combining photochemistry and tandem MS we develop a simple but effective workflow to enable large-scale and near-complete lipid structure characterization with a powerful capability of identifying C=C location(s) and sn -position(s) simultaneously. Quantitation of lipid structure isomers at multiple levels of specificity is achieved and different subtypes of human breast cancer cells are successfully discriminated. Remarkably, human lung cancer tissues can only be distinguished from adjacent normal tissues using quantitative results of both lipid C=C location and sn -position isomers.
研究领域:
生物化学
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医学
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质谱学
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PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2023
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IF 6.1
Wenwen Yang,Xiaoping Zhang,Jun Zhang,Guoshuan Wang,Hailong Liang,Xinglei Zhang,Konstantin Chingin,Huanwen Chen
The positions of C═C bonds in unsaturated fatty acids (FAs) are one of the main factors determining the quality of food flavor. Herein, we developed an approach for the determination of C═C bonds of FAs by online epoxidation reaction with water dimer radical cations. The limit of detection for octenoic acid isomers was ∼9 μg/L. The positions of C═C bonds in trans-2/3-hexenoic acid, trans-2/3-octenoic acid, oleic acid, linoleic acid, and linolenic acid in black tea or olive oil samples were directly determined by the established method. These results indicate that the established method allows the rapid determination of unsaturated FAs in black tea and olive oil. The advantages of this approach include the analysis speed (∼1 min per sample), simple device, and no need for complex pretreatment. This study not only provides a strategy for the determination of C═C positions but also offers new possibilities for applications in the field of food chemistry.
研究领域:
分析化学
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食品科学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2019
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IF 5.256
Lingzhong Wan,Guanda Gong,Hao Liang,Guangming Huang
In situ identification and quantification of unsaturated fatty acid (FA) C=C positional isomers in human serum is herein performed by negative-ion paper spray (PS) mass spectrometry. Typically, by direct application of an alternating current (AC) voltage to the wet paper, the PS ionization could perform stably in the negative-ion mode without severe discharge. We suppose epoxidation reaction between unsaturated C=C bonds and reactive oxidative species might be initiated by a mild electrical discharge, which could be rapidly and controllably produced via a low amplitude AC voltage. Upon collision-induce dissociation (CID), the epoxide was fragmented to generate diagnostic ions indicating the C=C location. The intensity of the characteristic product ions could also be used for absolute quantification of the FA C=C positional isomers. The limits of detection (LODs) and limits of quantification (LOQs) were roughly in the range of 0.0178–0.0506 μ M and 0.0218–0.3634 μ M for standard FAs. Without the additional sample preparations or reactive chemical reagents , epoxidation of unsaturated FAs and ionization of the epoxide could be achieved in one-step by negative-ion mode PS, which enable a promising methodology for on-site clinical diagnosis.
研究领域:
分析化学
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临床诊断
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质谱分析
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2024
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IF 6.7
Yuling Li,Jiahui Bai,Kuofeng Tseng,Xiaoqiang Zhang,Li Zhang,Jing Zhang,Wenjian Sun,Yinlong Guo
Free unsaturated fatty acids (UFA) are key intermediates of lipid metabolism and participate in many metabolic pathways with specific biological functions. Although various fragmentation-based methods for pinpointing C═C locations in UFA were developed, the current mass spectrometry methods are difficult to simultaneously differentiate geometric isomers and positional isomers in trace samples due to low ionization efficiency, low conversion, and low resolution. Herein, an intramolecular ring–chain equilibrium elimination strategy via 4-plex stable isotope labeling dual derivatization-assisted ion mobility-mass spectrometry was developed, thereby one-pot specifically labeling C═C and carboxyl groups among the trace and unstable UFA with high sensitivity, high efficiency, and good substrate generality. It achieved fast separation of both C═C positional and geometric isomers with high resolution, which benefited from eliminating the intramolecular ring–chain equilibrium by suppressing the formation of salt bridges between free carboxyl groups and pyridine cations. 4-plex stable isotope labeling reagents showed similar reactivity, enabling high-throughput quantitative analysis of omics. This method was successfully applied for accurate and rapid identification of the UFA composition in olive oil extract. These results suggest that the developed method provides new insight for rapid characterization of UFA C═C positional and geometric isomers in complex samples to explore disease biomarkers and food quality control indicators.
研究领域:
分析化学
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脂质组学
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质谱分析
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代谢组学
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PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2021
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IF 4.759
Yuhao Han,Panpan Chen,Zhichao Li,Xiao Wang,Chenglong Sun
Ultraviolet (UV) light-catalyzed Paternò-Büchi (PB) reaction has been developed as an efficient lipid C=C double bond (DB) derivatization strategy, which can accurately assign the position of C=C bond in unsaturated lipids when coupled with tandem mass spectrometry (MS/MS). Inspired by this, here we proposed a novel visible-light induced [2+2] cycloaddition reaction combined with ESI-MS/MS and MALDI-MS/MS to identify lipid C=C position isomers. Benz[g]isoquinoline-5,10-dione (BIQD) and 6,9-difluorobenzo[g]isoquinoline-5,10-dione (DF-BIQD) were developed as a new type of [2+2] cycloaddition reagent, which can not only react with C=C bond under 254 nm UV light irradiation, but also quickly combine with lipid C=C bond under the irradiation of 405 nm visible-light and > 400 nm compact fluorescent lamp visible-light. High cycloaddition reaction conversion efficiency can be achieved by irradiating under compact fluorescent lamp light for 2 min. Moreover, we discovered that 437 nm, 489 nm, 545 nm, 581 nm, and 613 nm monochromatic light appearing in compact fluorescent lamp can individually induce the [2 + 2] cycloaddition reaction between DF-BIQD and unsaturated lipids. Using this method, we found that the expressions of lipid DB-positional isomers in rat heart, brain, lung, spleen, thymus, kidney, liver and plasma vary greatly. The relative content of FA-18:1 (Δ9) in rat heart is only 1.49 times that of FA-18:1 (Δ11), while the relative content of FA-18:1 (Δ9) in rat plasma is 5.20 times that of FA-18:1 (Δ11). The above results offer new insight into the development of photocatalytic reagent for visible-light induced [2+2] cycloaddition and structural lipidomic studies.
研究领域:
化学
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生物化学
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分析化学
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脂质组学
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产品关联
DOI
PubMed
高影响因子
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