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Zhan L, Huang Y, Wang G. Multi-modal mass spectrometry imaging of a single tissue section. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5074. [PMID: 39017393 DOI: 10.1002/jms.5074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/10/2024] [Accepted: 06/21/2024] [Indexed: 07/18/2024]
Abstract
Mass spectrometry imaging (MSI) was developed to visualize spatial chemical information within tissues, thereby facilitating spatial multi-omic analysis. However, due to the limited spatial information provided by individual modal MSI, correlating various chemical data within tissues remains a significant challenge. In recent years, multimodal MSI has garnered considerable attention due to its ability to visualize the spatial distributions of multiple biomolecules within tissues. Among the strategies employed in this field, multimodal imaging on a single tissue section circumvents multiple issues introduced by integration of images of consecutive tissue sections. In this minireview, we provide an overview of multimodal MSI on a single tissue section, with a particular focus on the use of Matrix-Assisted Laser Desorption/Ionization-MSI for spatial multi-omic investigations that offer a comprehensive and in-depth elucidation of the biological state and activities, aiming to inspire the development of new approaches in this field.
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Affiliation(s)
- Lingpeng Zhan
- Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yanyi Huang
- Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, China
- Biomedical Pioneering Innovation Center, Peking University, Beijing, China
- College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Guanbo Wang
- Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, China
- Biomedical Pioneering Innovation Center, Peking University, Beijing, China
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2
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Cen X, Fang Y, Chen Z, Zhu X. Development of benzimidazole derivatives as efficient matrices for the analysis of acidic small-molecule compounds using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry in negative ion mode. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9751. [PMID: 38680091 DOI: 10.1002/rcm.9751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/17/2024] [Accepted: 03/18/2024] [Indexed: 05/01/2024]
Abstract
RATIONALE With the development of matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry (MS) in spatial localisation omics research on small molecules, the detection sensitivity of the matrix must increase. However, the types of matrices suitable for detecting acidic small molecules in (-) MALDI-MS mode are very limited and are either not sensitive enough or difficult to obtain. METHODS More than 10 commercially available benzimidazole and benzothiazole derivatives were selected as MALDI matrices in negative ion mode. MALDI-MS analysis was performed on 38 acidic small molecules and mouse serum, and the matrix effects were compared with those of the common commercial matrices 9-aminoacridine (9AA), 1,5-naphthalenediamine (DAN) and 3-aminoquinoline (3AQ). Moreover, the proton affinity (PA) of the selected potential matrix was calculated, and the relationships among the compound structure, PA value and matrix effect were discussed. RESULTS In (-) MALDI-MS mode, a higher PA value generally indicates a better matrix effect. Amino-substituted 2-phenyl-1H-benzo[d]imidazole derivatives had well-defined matrix effects on all analytes and were generally superior to the commonly used matrices 9AA, DAN and 3AQ. Among them, 2-(4-(dimethylamino-phenyl)-1H-benzo[d]imidazole-5-amine (E-4) has the best sensitivity and versatility for detecting different analytes and has the best ability to detect fatty acids in mouse serum; moreover, the limit of detection (LOD) of some analytes can reach as low as ng/L. CONCLUSIONS Compared to 9AA, DAN and 3AQ, matrix E-4 is more effective at detecting low-molecular-weight acidic compounds in (-) MALDI-MS mode, with higher sensitivity and better versatility. In addition, there is a clear correlation between compound structure, PA and matrix effects, which provides a basis for designing more efficient matrices.
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Affiliation(s)
- Xianyi Cen
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Yuhao Fang
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Zilong Chen
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
| | - Xinhai Zhu
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, China
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3
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Huang P, Zhang H, Liu Y, Li L. Rapid Characterization of Phospholipids from Biological Matrix Enabled by Indium Tin Oxide (ITO) Coated Slide Assisted Enrichment MALDI Mass Spectrometry. ANALYSIS & SENSING 2024; 4:e202300097. [PMID: 39309316 PMCID: PMC11415247 DOI: 10.1002/anse.202300097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Indexed: 09/25/2024]
Abstract
Lipidomic analysis of human serum is essential to monitor the individual's health status. Herein, we develop a facile strategy for rapid characterization of phospholipids in human serum via indium tin oxide (ITO) coated glass slide solid phase extraction MALDI mass spectrometry (ITO-SPE-MALDI-MS). Phospholipid species are retained on ITO slide via solid phase extraction owing to the unique property of the ITO material; the measurement of phospholipid species from 1 μl human serum within 2 min is achievable. A comparison of ITO-SPE strategy with conventional extraction methods was further carried out using liquid chromatography-mass spectrometry (LC-MS) and ion-mobility mass spectrometry (IM-MS), resulting in a comparable enrichment performance for the phospholipid analysis. Furthermore, rapid lipidomic profiling of serum samples from human colorectal cancer patients and cell lines was demonstrated. Our results indicate that ITO-SPE-MALDI-MS provides a higher throughput strategy for the analysis of phospholipid species in complex biological mixtures, showcasing its potential for applications in the analysis of clinical biofluids.
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Affiliation(s)
- Penghsuan Huang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706 (USA)
| | - Hua Zhang
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705 (USA)
| | - Yuan Liu
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705 (USA)
| | - Lingjun Li
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706 (USA)
- School of Pharmacy, University of Wisconsin-Madison, 777 Highland Ave, Madison, WI 53705 (USA)
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4
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Chen LC, Lee C, Hsu CC. Towards developing a matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) compatible tissue expansion protocol. Anal Chim Acta 2024; 1297:342345. [PMID: 38438227 DOI: 10.1016/j.aca.2024.342345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/05/2024] [Accepted: 02/04/2024] [Indexed: 03/06/2024]
Abstract
Mass spectrometry imaging (MSI) visualizes spatial distribution of molecules in a biological tissue. However, compared with traditional microscopy-based imaging, conventional MSI is limited to its spatial resolution, resulting in difficulties in identifying detailed tissue morphological characters, such as lesion boundary or nanoscale structures. On the other hand, expansion microscopy, a tissue expansion method widely used in optical imaging to improve morphological details, has great potential to solve insufficient spatial resolution in mass spectrometry imaging (MSI). However, expansion microscopy was not originally designed for MSI, resulting in problems while combining expansion microscopy and MSI such as expanded sample fragility, vacuum stability and molecule loss during sample preparation. In this research we developed a MALDI MSI compatible expansion protocol by adjusting sample preparation methods during tissue expansion, successfully combining expansion microscopy with MSI. After tissue expansion the expanded sample can be readily applied to MALDI MSI sample preparation and further data acquisition. The MALDI MSI compatible expansion protocol has great potential to be widely applied in MALDI MSI sample preparation to facilitate improvement of MSI spatial resolution.
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Affiliation(s)
- Li-Cyun Chen
- Department of Chemistry, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei City, 106319, Taiwan.
| | - Chuping Lee
- Department of Chemistry, National Chung Hsing University, No.145, Xingda Rd., South Dist., Taichung City, 40227, Taiwan.
| | - Cheng-Chih Hsu
- Department of Chemistry, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei City, 106319, Taiwan.
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5
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Liang Q, Mondal P, Li Q, Maqbool T, Zhao C, Jiang D, Szulczewski GJ, Wijeratne GB. Nitro Indole Derivatives as Novel Dual-Polarity Matrices for MALDI Mass Spectrometry and Imaging with Broad Applications. Anal Chem 2024; 96:1668-1677. [PMID: 38226847 DOI: 10.1021/acs.analchem.3c04684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
A new matrix framework is presented in this study for the improved ionization efficiency of complex mixtures by matrix-assisted laser desorption ionization (MALDI) mass spectrometry/imaging. Five nitro indole (NI) derivatives [3-methyl-4-nitro-1H-indole (3,4-MNI), 3-methyl-6-nitro-1H-indole (3,6-MNI), 2,3-dimethyl-4-nitro-1H-indole (2,3,4-DMNI), 2,3-dimethyl-6-nitro-1H-indole (2,3,6-DMNI), and 4-nitro-1H-indole (4-NI)] were synthesized and shown to produce both positive and negative ions with a broad class of analytes as MALDI matrices. NI matrices were compared to several common matrices, such as 2,5-dihydroxybenzoic acid (DHB), alpha-cyano-4-hydroxylcinnamic acid (CHCA), sinapinic acid (SA), 1,5-diaminonaphthelene (1,5-DAN), and 9-aminoacridine (9-AA), for the analysis of lipid, peptide, protein, glycan, and perfluorooctanesulfonic acid (PFOS) compounds. 3,4-MNI demonstrated the best performance among the NI matrices. This matrix resulted in reduced ion suppression and better detection sensitivity for complex mixtures, for example, egg lipids/milk proteins/PFOS in tap water, while 2,3,6-DMNI was the best matrix for blueberry tissue imaging. Several important aspects of this work are reported: (1) dual-polarity ion production with NI matrices and complex mixtures; (2) quantitative analysis of PFOS with a LOQ of 0.5 ppb in tap water and 0.05 ppb in MQ water (without solid phase extraction enrichment), with accuracy and precision within 5%; (3) MALDI imaging with 2,3,6-DMNI as a matrix for plant metabolite/lipid identification with ionization enhancement in the negative ion mode m/z 600-900 region; and (4) development of a thin film deposition under/above tissue method for MALDI imaging with a vacuum sublimation matrix on a high-vacuum MALDI instrument.
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Affiliation(s)
- Qiaoli Liang
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Pritam Mondal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India
| | - Qi Li
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Tahir Maqbool
- Department of Civil, Construction and Environmental Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Chao Zhao
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Daqian Jiang
- Department of Civil, Construction and Environmental Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Greg J Szulczewski
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Gayan B Wijeratne
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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6
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Chung HH, Huang P, Chen CL, Lee C, Hsu CC. Next-generation pathology practices with mass spectrometry imaging. MASS SPECTROMETRY REVIEWS 2023; 42:2446-2465. [PMID: 35815718 DOI: 10.1002/mas.21795] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Mass spectrometry imaging (MSI) is a powerful technique that reveals the spatial distribution of various molecules in biological samples, and it is widely used in pathology-related research. In this review, we summarize common MSI techniques, including matrix-assisted laser desorption/ionization and desorption electrospray ionization MSI, and their applications in pathological research, including disease diagnosis, microbiology, and drug discovery. We also describe the improvements of MSI, focusing on the accumulation of imaging data sets, expansion of chemical coverage, and identification of biological significant molecules, that have prompted the evolution of MSI to meet the requirements of pathology practices. Overall, this review details the applications and improvements of MSI techniques, demonstrating the potential of integrating MSI techniques into next-generation pathology practices.
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Affiliation(s)
- Hsin-Hsiang Chung
- Department of Chemistry, National Taiwan University, Taipei City, Taiwan
| | - Penghsuan Huang
- Department of Chemistry, National Taiwan University, Taipei City, Taiwan
| | - Chih-Lin Chen
- Department of Chemistry, National Taiwan University, Taipei City, Taiwan
| | - Chuping Lee
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Cheng-Chih Hsu
- Department of Chemistry, National Taiwan University, Taipei City, Taiwan
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7
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Song Q, Liu Z, Niu J, Zheng B, Hao J, Jiang J. A two-photon fluorescent probe for formaldehyde detection and regeneration in living cells. J Mater Chem B 2023; 11:4408-4415. [PMID: 37161642 DOI: 10.1039/d3tb00158j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A two-photon excited fluorescent probe CMB-1 has been rationally developed for the detection and regeneration of formaldehyde based on a novel nucleophilic addition of a secondary amine to FA and subsequential alcoholysis reactivity mechanism. It enables a specific turn-on response towards formaldehyde and facilitates the monitoring of exogenous and endogenous formaldehyde in living cells via both one- and two-photon microscopy, with minimal influence on its native homeostasis and local concentration.
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Affiliation(s)
- Qi Song
- Key Laboratory of the Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Zhiqiang Liu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Jie Niu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Bowen Zheng
- Key Laboratory of the Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Jingcheng Hao
- Key Laboratory of the Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Jie Jiang
- Key Laboratory of the Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
- Shenzhen Research Institute of Shandong University, Shenzhen 518057, P. R. China
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8
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020. MASS SPECTROMETRY REVIEWS 2022:e21806. [PMID: 36468275 DOI: 10.1002/mas.21806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.
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Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire, United Kingdom
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9
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Liu H, Pan Y, Xiong C, Han J, Wang X, Chen J, Nie Z. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) for in situ analysis of endogenous small molecules in biological samples. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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10
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Baquer G, Sementé L, Mahamdi T, Correig X, Ràfols P, García-Altares M. What are we imaging? Software tools and experimental strategies for annotation and identification of small molecules in mass spectrometry imaging. MASS SPECTROMETRY REVIEWS 2022:e21794. [PMID: 35822576 DOI: 10.1002/mas.21794] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Mass spectrometry imaging (MSI) has become a widespread analytical technique to perform nonlabeled spatial molecular identification. The Achilles' heel of MSI is the annotation and identification of molecular species due to intrinsic limitations of the technique (lack of chromatographic separation and the difficulty to apply tandem MS). Successful strategies to perform annotation and identification combine extra analytical steps, like using orthogonal analytical techniques to identify compounds; with algorithms that integrate the spectral and spatial information. In this review, we discuss different experimental strategies and bioinformatics tools to annotate and identify compounds in MSI experiments. We target strategies and tools for small molecule applications, such as lipidomics and metabolomics. First, we explain how sample preparation and the acquisition process influences annotation and identification, from sample preservation to the use of orthogonal techniques. Then, we review twelve software tools for annotation and identification in MSI. Finally, we offer perspectives on two current needs of the MSI community: the adaptation of guidelines for communicating confidence levels in identifications; and the creation of a standard format to store and exchange annotations and identifications in MSI.
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Affiliation(s)
- Gerard Baquer
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
| | - Lluc Sementé
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
| | - Toufik Mahamdi
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
| | - Xavier Correig
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
- Institut D'Investigacio Sanitaria Pere Virgili, Tarragona, Spain
| | - Pere Ràfols
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
- Institut D'Investigacio Sanitaria Pere Virgili, Tarragona, Spain
| | - María García-Altares
- Department of Electronic Engineering, University Rovira I Virgili, Tarragona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
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11
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Wan K, Jiang X, Tang X, Xiao L, Chen Y, Huang C, Zhu F, Wang F, Xu H. Study on Absorption, Distribution, Metabolism, and Excretion Properties of Novel Insecticidal GABA Receptor Antagonist, Pyraquinil, in Diamondback Moth Combining MALDI Mass Spectrometry Imaging and High-Resolution Mass Spectrometry. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:6072-6083. [PMID: 35576451 DOI: 10.1021/acs.jafc.2c00468] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A thorough understanding of absorption, distribution, metabolism, and excretion (ADME) of insecticide candidates is essential in insecticide development and structural optimization. Here, ADME of pyraquinil, a novel insecticidal GABA receptor antagonist, in Plutella xylostella larvae during the accumulation phase and depuration phase was investigated separately using a combination of UHPLC-Q-Orbitrap, HPLC-MS/MS, and MALDI-MSI. Five new metabolites of pyraquinil were identified, and a metabolic pathway was proposed. The oxidative metabolite (pyraquinil-sulfone) was identified as the main metabolite and confirmed by its standard. Quantitative results showed that pyraquinil was taken up by the larvae rapidly and then undergone a cytochrome P450s-mediated oxidative transformation into pyraquinil-sulfone. Both fecal excretion and oxidative metabolism were demonstrated to be predominant ways to eliminate pyraquinil in P. xylostella larvae during accumulation, while oxidative metabolism followed by fecal excretion was probably the major pathway during depuration. MALDI-MSI revealed that pyraquinil was homogeneously distributed in the larvae, while pyraquinil-sulfone presented a continuous enrichment in the midgut during accumulation. Conversely, pyraquinil-sulfone located in hemolymph can be preferentially eliminated during depuration, suggesting its tissue tropism. It improves the understanding of the fate of pyraquinil in P. xylostella and provides useful information for insecticidal mechanism elucidation and structural optimization of pyraquinil.
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Affiliation(s)
- Kai Wan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510640, China
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Xunyuan Jiang
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Xuemei Tang
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Lu Xiao
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Yan Chen
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Congling Huang
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Fuwei Zhu
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Fuhua Wang
- Institute of Quality Standard and Monitoring Technology for Agro-products of Guangdong Academy of Agricultural Sciences and Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-products, Guangzhou 510640, China
| | - Hanhong Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510640, China
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12
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Jin Z, Liu M, Huang X, Zhang X, Qu Z, Zhu JJ, Min Q. Top-Down Rational Engineering of Heteroatom-Doped Graphene Quantum Dots for Laser Desorption/Ionization Mass Spectrometry Detection and Imaging of Small Biomolecules. Anal Chem 2022; 94:7609-7618. [PMID: 35575691 DOI: 10.1021/acs.analchem.2c00802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is widely applied in mapping macrobiomolecules in tissues, but it is still limited in profiling low-molecular-weight (MW) compounds (typically metabolites) due to ion interference and suppression by organic matrices. Here, we present a versatile "top-down" strategy for rational engineering of carbon material-based matrices, by which heteroatom-doped graphene quantum dots (HGQDs) were manufactured for LDI MS detection and imaging of small biomolecules. The HGQDs derived from parent materials inherited the π-conjugated networks and doping sites for promoting energy transfer and negative ion generation, while their extremely small size guaranteed the matrix uniformity and signal reproducibility in LDI MSI. Compared to other HGQDs, nitrogen-doped graphene quantum dots (NGQDs) exhibited superior capability of assisting LDI of various small molecules, including amino acids, fatty acids, saccharides, small peptides, nucleobases, anticancer drugs, and bisphenol pollutants. Density functional theory simulations also corroborated that the LDI efficiency was markedly raised by the proton-capturing pyridinic nitrogen species and compromised by the electron-deficient boron dopants. NGQDs-assisted LDI MS further enabled label-free investigation on enzyme kinetics using an ordinary short peptide as the substrate. Moreover, due to the high salt tolerance and signal reproducibility, the proposed negative-ion NGQDs-assisted LDI MSI was able to reveal the abundance and distribution of low-MW species in rat brain tissue and achieved the imaging of low-MW lipids in coronally sectioned rat brains subjected to traumatic brain injury. Our work offers a new route for customizing nanomaterial matrices toward LDI MSI of small biomolecules in biomedical and pathological research.
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Affiliation(s)
- Zehui Jin
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Meng Liu
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xiaodan Huang
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xuemeng Zhang
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zexing Qu
- Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Jun-Jie Zhu
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Qianhao Min
- State Key Laboratory of Analytical Chemistry for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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13
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Borisov RS, Matveeva MD, Zaikin VG. Reactive Matrices for Analytical Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry. Crit Rev Anal Chem 2021; 53:1027-1043. [PMID: 34969337 DOI: 10.1080/10408347.2021.2001309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
In recent years, a special focus is placed on the usage of reactive matrices for analytical matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). Since 2003, when the term "reactive matrices" was suggested and the dignity of compounds, possessing dualistic properties as matrices and derivatization agents was demonstrated, corresponding approach has found application in various fields and, in particular, in bioanalysis (metabolomics, lipidomics, etc.). The main advantage of this methodology is that it reduces sample treatment time, simplifies the procedure of sample handling, improves the sensitivity of analysis, enhances the molecular identification and profiling. Within the framework of this review, the main attention is paid to "true" reactive matrices that interact with analyte molecules through an exchange or addition reactions. A special section discusses practical application of reactive matrices in the determination of the distribution of targeted and non-targeted organic substances on the surface of biological tissue sections by MALDI-MS imaging. In this critical review, a controversial proposal is made to consider protonating and deprotonating matrices as reactive, because they can undergo a chemical reaction such as proton transfer that occurs in both target solution and MALDI plume. In this respect, special attention is paid to "proton sponge" matrices that have found a wide application in the analysis of various acidic compounds by MALDI-MS in the negative mode. Historical data on the formation of ions and the fate of matrices in MALDI are considered at the beginning of this article.
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Affiliation(s)
- Roman S Borisov
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
| | - Mariya D Matveeva
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
| | - Vladimir G Zaikin
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
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Yang TL, Huang CL, Lee CP. Utilizing AgNPt-SALDI to Classify Edible Oils by Multivariate Statistics of Triacylglycerol Profile. Molecules 2021; 26:molecules26195880. [PMID: 34641425 PMCID: PMC8510378 DOI: 10.3390/molecules26195880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/24/2021] [Accepted: 09/25/2021] [Indexed: 11/16/2022] Open
Abstract
Edible oils are valuable sources of nutrients, and their classification is necessary to ensure high quality, which is essential to food safety. This study reports the establishment of a rapid and straightforward SALDI-TOF MS platform used to detect triacylglycerol (TAG) in various edible oils. Silver nanoplates (AgNPts) were used to optimize the SALDI samples for high sensitivity and reproducibility of TAG signals. TAG fingerprints were combined with multivariate statistics to identify the critical features of edible oil discrimination. Eleven various edible oils were discriminated using principal component analysis (PCA). The results suggested the creation of a robust platform that can examine food adulteration and food fraud, potentially ensuring high-quality foods and agricultural products.
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Affiliation(s)
- Tzu-Ling Yang
- Department of Applied Chemistry, National Chiayi University, Chiayi City 60004, Taiwan; (T.-L.Y.); (C.-L.H.)
| | - Cheng-Liang Huang
- Department of Applied Chemistry, National Chiayi University, Chiayi City 60004, Taiwan; (T.-L.Y.); (C.-L.H.)
| | - Chu-Ping Lee
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan
- Correspondence:
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15
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Müller WH, De Pauw E, Far J, Malherbe C, Eppe G. Imaging lipids in biological samples with surface-assisted laser desorption/ionization mass spectrometry: A concise review of the last decade. Prog Lipid Res 2021; 83:101114. [PMID: 34217733 DOI: 10.1016/j.plipres.2021.101114] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 02/06/2023]
Abstract
Knowing the spatial location of the lipid species present in biological samples is of paramount importance for the elucidation of pathological and physiological processes. In this context, mass spectrometry imaging (MSI) has emerged as a powerful technology allowing the visualization of the spatial distributions of biomolecules, including lipids, in complex biological samples. Among the different ionization methods available, the emerging surface-assisted laser desorption/ionization (SALDI) MSI offers unique capabilities for the study of lipids. This review describes the specific advantages of SALDI-MSI for lipid analysis, including the ability to perform analyses in both ionization modes with the same nanosubstrate, the detection of lipids characterized by low ionization efficiency in MALDI-MS, and the possibilities of surface modification to improve the detection of lipids. The complementarity of SALDI and MALDI-MSI is also discussed. Finally, this review presents data processing strategies applied in SALDI-MSI of lipids, as well as examples of applications of SALDI-MSI in biomedical lipidomics.
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Affiliation(s)
- Wendy H Müller
- Mass Spectrometry Laboratory, MolSys RU, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000 Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys RU, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000 Liège, Belgium
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys RU, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000 Liège, Belgium
| | - Cedric Malherbe
- Mass Spectrometry Laboratory, MolSys RU, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000 Liège, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys RU, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000 Liège, Belgium.
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16
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Tang W, Gordon A, Wang F, Chen Y, Li B. Hydralazine as a Versatile and Universal Matrix for High-Molecular Coverage and Dual-Polarity Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging. Anal Chem 2021; 93:9083-9093. [PMID: 34152727 DOI: 10.1021/acs.analchem.1c00498] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Few matrices have the potential to be universally applicable for imaging vast endogenous compounds ranging from micro to macromolecules. In this article, we present hydralazine (HZN) as a versatile and universal matrix for matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) of a wide range of endogenous compounds between 50.0 and 20,000.0 Da. HZN was prepared from its hydrochloride by alkalizing HZN·HCl with ammonia to enhance the optical absorptivity at the preferred MALDI UV laser wavelength. To further improve its performance for MALDI MS, HZN was doped with NH4OH or TFA, resulting in matrix superior performance for imaging biologically relevant compounds in the negative and positive-ion modes, respectively. The analyte-matrix interaction was also enhanced by the optimized matrix solvent and the deposition amount. Compared with conventional matrices such as 2,5-dihydroxybenzoic acid, α-cyano-4-hydroxycinnamic acid, and 9-aminoacridine (9-AA), the HZN matrix provided higher sensitivity, broader molecular coverage, and improved signal intensities. Its broad acquisition range makes it versatile for imaging small molecular metabolites and lipids, as well as proteins. In addition, HZN was applied successfully for the visualization of tissue-specific distributions and changes of small molecules, lipids, and proteins in the kidney and liver sections of obese ob/ob and diabetic db/db mice. The use of the HZN matrix shows great potential application in the field of pathological research.
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Affiliation(s)
- Weiwei Tang
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Andrew Gordon
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Fang Wang
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yanwen Chen
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Bin Li
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
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Dos Santos NA, de Almeida CM, Gonçalves FF, Ortiz RS, Kuster RM, Saquetto D, Romão W. Analysis of Erythroxylum coca Leaves by Imaging Mass Spectrometry (MALDI-FT-ICR IMS). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:946-955. [PMID: 33715356 DOI: 10.1021/jasms.0c00449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) can determine the chemical identity and spatial distribution of several molecules in a single analysis, conserving its natural histology. However, there are no specific studies on the spatial distribution of alkaloids in Erythroxylum coca leaves by MALDI IMS, preserving the histology of the monitored compounds. Therefore, in this work, positive-ion mode MALDI Fourier-transform ion cyclotron resonance imaging mass spectrometry (MALDI(+)FT-ICR IMS) was applied to identify and analyze the distribution of alkaloids on the surface of coca leaves, evaluating the ionization efficiency of three matrices (α-cyano-4-hydroxycinnamic acid (CHCA), 2-mercaptobenzothiazole (MBT), and 2,5-dihydroxybenzoic acid (DHB)). The last was chosen as the best matrix in this study, and it was studied in five concentrations (0.5, 1.0, 2.0, 4.0, and 8.0 mg·mL-1), where 2 mg·mL-1 was the most efficient. The washing of coca leaves with the organic solvents (acetonitrile, methanol, toluene, and dichloromethane) tested did not improve the performance of the ionization process. Finally, a tissue section, 50 μm thick, was used to study the inner part of the leaf tissue, where alkaloids and flavonoid molecules were detected.
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Affiliation(s)
- Nayara Araujo Dos Santos
- Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29075-910, Brazil
- Instituto Nacional de Ciência e Tecnologia Forense (INCT Forense), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
| | - Camila Medeiros de Almeida
- Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29075-910, Brazil
- Instituto Nacional de Ciência e Tecnologia Forense (INCT Forense), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
| | - Fernanda Fachim Gonçalves
- Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29075-910, Brazil
| | - Rafael Scorsatto Ortiz
- Instituto Nacional de Ciência e Tecnologia Forense (INCT Forense), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
- Superintendência da Polícia Federal no Rio Grande Sul, Porto Alegre, RS 90040-410, Brazil
| | - Ricardo Machado Kuster
- Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29075-910, Brazil
| | - Diemerson Saquetto
- Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo (IFES), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
| | - Wanderson Romão
- Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29075-910, Brazil
- Instituto Nacional de Ciência e Tecnologia Forense (INCT Forense), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
- Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo (IFES), Av. Ministro Salgado Filho, Soteco, Vila Velha, Espírito Santo 29106-010, Brazil
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Tammekivi E, Ghiami-Shomami A, Tshepelevitsh S, Trummal A, Ilisson M, Selberg S, Vahur S, Teearu A, Lõkov M, Peets P, Pagano T, Leito I. Experimental and Computational Study of Aminoacridines as MALDI(-)-MS Matrix Materials for the Analysis of Complex Samples. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1080-1095. [PMID: 33726494 DOI: 10.1021/jasms.1c00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Monoaminoacridines (1-, 2-, 3-, 4-, and 9-aminoacridine) were studied for suitability as matrices in the negative ion mode matrix-assisted laser desorption/ionization mass spectrometry (MALDI(-)-MS) analysis of various samples. This is the first study to examine 1-, 2-, and 4-aminoacridine as potential matrix material candidates for MALDI(-)-MS. In addition, spectral (UV-Vis absorption and fluorescence), proton transfer-related (basicity and autoprotolysis), and crystallization properties of these compounds were characterized experimentally and/or computationally. For testing the capabilities of these aminoacridines as matrix materials, four samples related to cultural heritage materials-stearic acid, colophony resin, dyer's madder dye, and a resinous case-study sample from a shipwreck-were analyzed with MALDI(-)-MS. A novel algorithm (implemented as an executable Python script) for MS data analysis was developed to compare the five matrix materials and to help mass spectrometrists rapidly identify peaks originating from the sample and matrix material. It was determined that all five of the studied aminoacridines can successfully be used as matrix materials in MALDI(-)-MS analysis. As an interesting finding, in several cases, the best mass spectra were obtained by using a relatively small amount of matrix material mixed with an excess amount of sample. 3- and 4-aminoacridine outperformed the other aminoacridines in the ease of obtaining acceptable spectra, average number of ions identified in the mass spectra, and low dependence of the sample-to-matrix mass ratio on experimental results.
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Affiliation(s)
- Eliise Tammekivi
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Ali Ghiami-Shomami
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Sofja Tshepelevitsh
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Aleksander Trummal
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Mihkel Ilisson
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Sigrid Selberg
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Signe Vahur
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Anu Teearu
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Märt Lõkov
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Pilleriin Peets
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
| | - Todd Pagano
- Department of Science & Mathematics, Rochester Institute of Technology, 14623 Rochester, New York, United States
| | - Ivo Leito
- University of Tartu, Institute of Chemistry, Ravila 14a, 50411 Tartu, Estonia
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Zhou Q, Fülöp A, Hopf C. Recent developments of novel matrices and on-tissue chemical derivatization reagents for MALDI-MSI. Anal Bioanal Chem 2020; 413:2599-2617. [PMID: 33215311 PMCID: PMC8007514 DOI: 10.1007/s00216-020-03023-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/17/2020] [Accepted: 10/22/2020] [Indexed: 02/07/2023]
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a fast-growing technique for visualization of the spatial distribution of the small molecular and macromolecular biomolecules in tissue sections. Challenges in MALDI-MSI, such as poor sensitivity for some classes of molecules or limited specificity, for instance resulting from the presence of isobaric molecules or limited resolving power of the instrument, have encouraged the MSI scientific community to improve MALDI-MSI sample preparation workflows with innovations in chemistry. Recent developments of novel small organic MALDI matrices play a part in the improvement of image quality and the expansion of the application areas of MALDI-MSI. This includes rationally designed/synthesized as well as commercially available small organic molecules whose superior matrix properties in comparison with common matrices have only recently been discovered. Furthermore, on-tissue chemical derivatization (OTCD) processes get more focused attention, because of their advantages for localization of poorly ionizable metabolites and their‚ in several cases‚ more specific imaging of metabolites in tissue sections. This review will provide an overview about the latest developments of novel small organic matrices and on-tissue chemical derivatization reagents for MALDI-MSI. Graphical abstract ![]()
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Affiliation(s)
- Qiuqin Zhou
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany
| | - Annabelle Fülöp
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany.
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20
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Dual-polarity SALDI FT-ICR MS imaging and Kendrick mass defect data filtering for lipid analysis. Anal Bioanal Chem 2020; 413:2821-2830. [PMID: 33125540 DOI: 10.1007/s00216-020-03020-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/30/2020] [Accepted: 10/20/2020] [Indexed: 12/16/2022]
Abstract
Lipids are biomolecules of crucial importance involved in critical biological functions. Yet, lipid content determination using mass spectrometry is still challenging due to their rich structural diversity. Preferential ionisation of the different lipid species in the positive or negative polarity is common, especially when using soft ionisation mass spectrometry techniques. Here, we demonstrate the potency of a dual-polarity approach using surface-assisted laser desorption/ionisation coupled to Fourier transform-ion cyclotron resonance (SALDI FT-ICR) mass spectrometry imaging (MSI) combined with Kendrick mass defect data filtering to (i) identify the lipids detected in both polarities from the same tissue section and (ii) show the complementarity of the dual-polarity data, both regarding the lipid coverage and the spatial distributions of the various lipids. For this purpose, we imaged the same mouse brain section in the positive and negative ionisation modes, on alternate pixels, in a SALDI FT-ICR MS imaging approach using gold nanoparticles (AuNPs) as dual-polarity nanosubstrates. Our study demonstrates, for the first time, the feasibility of (i) a dual-polarity SALDI-MSI approach on the same tissue section, (ii) using AuNPs as nanosubstrates combined with a FT-ICR mass analyser and (iii) the Kendrick mass defect data filtering applied to SALDI-MSI data. In particular, we show the complementarity in the lipids detected both in a given ionisation mode and in the two different ionisation modes. Graphical abstract.
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Wäldchen F, Mohr F, Wagner AH, Heiles S. Multifunctional Reactive MALDI Matrix Enabling High-Lateral Resolution Dual Polarity MS Imaging and Lipid C═C Position-Resolved MS 2 Imaging. Anal Chem 2020; 92:14130-14138. [PMID: 32924439 DOI: 10.1021/acs.analchem.0c03150] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Local lipid variations in tissues are readily revealed with mass spectrometry imaging (MSI) methods, and the resulting lipid distributions serve as bioanalytical signatures to reveal cell- or tissue-specific lipids. Comprehensive MSI lipid mapping requires measurements in both ion polarities. Additionally, structural lipid characterization is necessary to link the lipid structure to lipid function. Whereas some structural elements of lipids are readily derived from high-resolution mass spectrometry (MS) and tandem-MS (MSn), the localization of C═C double bonds (DBs) requires specialized fragmentation and/or functionalization methods. In this work, we identify a multifunctional matrix-assisted laser desorption/ionization (MALDI) matrix for spatially resolved lipidomics investigations that reacts with lipids in Paternò-Büchi (PB) reactions during laser irradiation facilitating DB-position assignment and allows dual-polarity high-resolution MALDI-MSI and MALDI MS2I studies. By screening 12 compounds for improved ionization efficiency in positive-/negative-ion mode and the functionalization yield compared to the previously introduced reactive MALDI matrix benzophenone, 2-benzoylpyridine (BzPy) is identified as the best candidate. The new matrix enables DB localization of authentic standards belonging to 12 lipid classes and helps to assign 133/58 lipid features in positive-/negative-ion mode from mouse cerebellum tissue. The analytical capabilities of BzPy as a multifunctional MALDI-MSI matrix are demonstrated by imaging endogenous and PB-functionalized lipids in mouse kidney sections with 7 μm lateral resolution in both ion modes. Tracking diagnostic lipid DB-position fragment ions in mouse pancreatic tissue with down to 10 μm pixel size allows us to identify the islets of Langerhans associated with lipid isomer upregulation and depletion.
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Affiliation(s)
- Fabian Wäldchen
- Institute of Inorganic and Analytical Chemistry, Analytical Chemistry, Justus Liebig University Giessen, Heinrich Buff Ring 17, 35392 Giessen, Germany
| | - Franziska Mohr
- Department of Cardiovascular Physiology, Heidelberg University, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Andreas H Wagner
- Department of Cardiovascular Physiology, Heidelberg University, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Sven Heiles
- Institute of Inorganic and Analytical Chemistry, Analytical Chemistry, Justus Liebig University Giessen, Heinrich Buff Ring 17, 35392 Giessen, Germany
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