Institute of Inorganic and Analytical Chemistry, Analytical Chemistry , Justus Liebig University Giessen , Heinrich Buff Ring 17 , 35392 Giessen , Germany.
J Am Chem Soc. 2019 Jul 31;141(30):11816-11820. doi: 10.1021/jacs.9b05868. Epub 2019 Jul 22.
The location and identity of phospholipids (PLs) within tissues can serve as diagnostic markers for tissue types or diseases. Whereas mass spectrometry imaging (MSI) has emerged as a powerful bioanalytical tool to visualize PL distributions, inferring PL identities from MSI experiments is challenging. Especially, C═C double-bond (DB) positions are not identifiable in most MSI experiments. Herein, we introduce benzophenone (BPh) as a novel reactive matrix for matrix-assisted laser desorption/ionization (MALDI). BPh promotes desorption/ionization and simultaneously serves as derivatization reagent that allows functionalization of unsaturated PLs during the MALDI process via a laser-light driven Paternò-Büchi (PB) reaction without the need for additional equipment. Using BPh, PB product ions of numerous PL classes are readily generated to pinpoint the location of DBs. High lateral resolution MSI results of DB-position isomers are presented, highlighting the capabilities of BPh as a PB-reactive MALDI matrix to potentially unveil the impact of DB-position isomers in PL metabolism.
磷脂（PLs）在组织中的位置和身份可以作为组织类型或疾病的诊断标志物。尽管质谱成像（MSI）已经成为一种强大的生物分析工具，可以可视化 PL 分布，但从 MSI 实验中推断 PL 身份具有挑战性。特别是，在大多数 MSI 实验中，C═C 双键（DB）位置无法识别。在此，我们介绍二苯甲酮（BPh）作为一种用于基质辅助激光解吸/电离（MALDI）的新型反应基质。BPh 促进解吸/电离，同时作为衍生试剂，在 MALDI 过程中通过激光驱动的 Paternò-Büchi（PB）反应使不饱和 PL 官能化，而无需额外的设备。使用 BPh，很容易生成许多 PL 类的 PB 产物离子，以确定 DB 的位置。展示了 DB 位置异构体的高横向分辨率 MSI 结果，突出了 BPh 作为 PB 反应 MALDI 基质的能力，有可能揭示 DB 位置异构体对 PL 代谢的影响。
