3,4-Dimethoxycinnamic Acid as a Novel Matrix for Enhanced In Situ Detection and Imaging of Low-Molecular-Weight Compounds in Biological Tissues by MALDI-MSI.
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IF: 8.008
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Cited by: 59
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Abstract

Low-molecular-weight (low-MW) compounds have many essential functions in biological processes, and the molecular imaging of as many low-MW compounds as possible is critical for understanding complex biological processes. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is an emerging molecular-imaging technology that enables determination of the spatial distributions and the relative abundances of diverse endogenous compounds in tissues. New matrices suitable for the imaging of low-MW compounds by MALDI-MSI are important for the technological advancement of tissue imaging. In this study, 3,4-dimethoxycinnamic acid (DMCA) was evaluated as a new matrix for enhanced low-MW compound detection by MALDI-MSI because of its strong ultraviolet absorption, low matrix-ion related interferences below m/ z 500, and high ionization efficiency for the analysis of low-MW compounds. DMCA was successfully used for improved in situ detection of low-molecular-weight metabolites ( m/ z < 500) and lipids in rat liver, rat brain, and germinating Chinese-yew seed tissue sections. The use of DMCA led to the successful in situ detection of 303, 200, and 248 low-MW compound ion signals from these three tissues, respectively. Both MALDI-MS/MS and LC-MS/MS were used to identify these ion signals, leading to the identification of 115 low-MW compounds from rat liver (including 53 lipids, 29 oligopeptides, and 33 metabolites), 130 low-MW compounds from rat brain (including 104 lipids, 5 oligopeptides, and 21 metabolites), and 111 low-MW compounds from germinating Chinese-yew seeds (including 77 lipids, 22 oligopeptides, 8 flavonoids, and 4 alkaloids). A larger number of low-MW compounds could be detected and imaged when DMCA was used as the MALDI matrix than with other commonly used MALDI matrices such as 2,5-dihydroxybenzoic acid, α-cyano-4-hydroxycinnamic acid, 2-mercaptobenzothiazole, graphene oxide, and silver nanoparticles. Our work provides a new and powerful matrix for enhanced MALDI-MS profiling of low-MW compounds in both animal and plant tissues.

Keywords

MALDI
MALDI-MSI

MeSH terms

Animals
Brain
Brain Chemistry
Cinnamates
Limit of Detection
Lipids
Liver
Male
Organic Chemicals
Peptides
Rats, Sprague-Dawley
Seeds
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Taxus
Ultraviolet Rays

Authors

He, Huixin
Qin, Liang
Zhang, Yawen
Han, Manman
Li, Jinming
Liu, Yaqin
Qiu, Kaidi
Dai, Xiaoyan
Li, Yanyan
Zeng, Maomao
Guo, Huihong
Zhou, Yijun
Wang, Xiaodong

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