戊甲基吲哚盐是具有高线粒体选择性的有希望的荧光探针和抗癌剂。我们合成了两种吲哚戊甲基盐：一个是环状形式，其中喹啉直接嵌入了戊甲基链中（cPMS），另一个是开放形式，其中喹啉在γ位发生了取代（oPMS）。为了更好地了解它们的性质，我们通过光谱方法（UV-Vis、荧光和NMR光谱）研究了其与线粒体磷脂（心磷脂和磷酰胆碱）的相互作用。两种化合物都显示出与心磷脂和磷酰胆碱的显著亲和性，这与它们的UV-Vis光谱的明显变化有关。然而，令人惊讶的是，我们观察到cPMS在与心磷脂和磷酰胆碱的复合物中的荧光性质发生了变化，而oPMS只在与心磷脂的复合物中发生了变化。两种盐，尤其是cPMS，在线粒体成像和对抗癌细胞的细胞毒性方面具有高可用性。以上清楚地表明，戊甲基和喹啉基团的共轭体，尤其是cPMS，是设计线粒体特异性药剂的有希望的结构基元。Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.

Pentamethinium indolium salts are promising fluorescence probes and anticancer agents with high mitochondrial selectivity. We synthesized two indolium pentamethinium salts: a cyclic form with quinoxaline directly incorporated in the pentamethinium chain (cPMS) and an open form with quinoxaline substitution in the γ-position (oPMS). To better understand their properties, we studied their interaction with mitochondrial phospholipids (cardiolipin and phosphatidylcholine) by spectroscopic methods (UV-Vis, fluorescence, and NMR spectroscopy). Both compounds displayed significant affinity for cardiolipin and phosphatidylcholine, which was associated with a strong change in their UV-Vis spectra. Nevertheless, we surprisingly observed that fluorescence properties of cPMS changed in complex with both cardiolipin and phosphatidylcholine, whereas those of oPMS only changed in complex with cardiolipin. Both salts, especially cPMS, display high usability in mitochondrial imaging and are cytotoxic for cancer cells. The above clearly indicates that conjugates of pentamethinium and quinoxaline group, especially cPMS, represent promising structural motifs for designing mitochondrial-specific agents.Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.