Endogenous metabolites play key functions in many important physiological and biochemical processes. The comprehensive detection and direct imaging of metabolites in bio-tissues by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is very important for understanding complex and diverse biological processes and has become an essential aspect of spatial omics. In this work, 4-aminoazobenzene (AAB) was successfully screened and optimized as a new negative ion (-)MALDI matrix to enhance the detection and imaging of metabolites in tissues using MALDI-MSI. Obviously, AAB exhibited superior properties in terms of ultraviolet absorption, background ion interference, matrix morphology, and metabolite ionization efficiency. AAB was used for detection and imaging of metabolites in rat brain and germinating Chinese yew seed tissue sections, where 264 and 339 metabolite ion signals were successfully detected and imaged using (-)MALDI-MS, respectively. In addition, high-resolution imaging of mouse eyeball section using MALDI-timsTOF MSI with spatial resolution of up to 10 μm was successfully carried out, showing that AAB is an efficient (-)MALDI matrix for capturing high-resolution images of metabolites in biological tissue sections.

中文翻译：

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4-氨基偶氮苯：一种新型负离子基质，用于增强代谢物的 MALDI 组织成像

内源代谢物在许多重要的生理生化过程中发挥着关键作用。通过基质辅助激光解吸/电离质谱成像（MALDI-MSI）对生物组织中的代谢物进行全面检测和直接成像对于理解复杂多样的生物过程非常重要，并已成为空间组学的重要方面。在这项工作中，成功筛选并优化了 4-氨基偶氮苯 (AAB) 作为一种新的负离子 (-)MALDI 基质，以增强使用 MALDI-MSI 对组织中代谢物的检测和成像。显然，AAB 在紫外吸收、背景离子干扰、基质形态和代谢物电离效率方面表现出优越的性能。AAB 用于大鼠大脑和发芽红豆杉种子组织切片中代谢物的检测和成像，其中 (-)MALDI-MS 分别成功检测到 264 和 339 个代谢物离子信号并成像。此外，使用MALDI-timsTOF MSI成功地对小鼠眼球切片进行了高分辨率成像，空间分辨率高达10μm，表明AAB是一种有效的(-)MALDI矩阵，用于捕获生物体内代谢物的高分辨率图像。组织切片。