School of Pharmaceutical Science, Sun Yat-sen University, Guangzhou 510006, China.
School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.
Molecules. 2018 Sep 7;23(9):2290. doi: 10.3390/molecules23092290.
Fluorophores with aggregation-induced emission enhancement (AIEE) properties have attracted more attention in recent years. In order to realise more valuable applications, the different kinds of AIEE molecules are in serious need of further development. Therefore, a novel flavone-based AIEE system derived from restriction of intramolecular rotation (RIR) was designed and synthesized in this work. The results revealed that six of the compounds showed typical AIEE characteristics, with fluorescence emissions from purple, blue, cyan to green, tunable by changing substituent groups. This flavone-based AIEE system has never been reported before. The AIEE characteristics were investigated by optical spectroscopy, fluorescence photographs, scanning electron microscopy (SEM), fluorescence quantum yields (Ф) and fluorescence lifetime in the CH₃OH/H₂O mixed solution. Moreover, benefiting from the simple structures and small molecular weight, they could permeate cells faster than current high-molecular-weight AIEE molecules. Furthermore, to examine possible biomedical applications, fluorescence imaging in living A549 lung cells and cell viabilities were examined, and the results displayed that these fluorophores showed good cellular uptake and low cytotoxicity within the experimental concentration range. In addition, these AIEE compounds possessed excellent specificity for mitochondrial targeting and mitochondrial morphological change tracking, besides, they displayed superior photostability, which indicated they are potential candidates for mitochondrial imaging.
近年来，具有聚集诱导发光增强（AIEE）性质的荧光团引起了更多的关注。为了实现更有价值的应用，不同种类的 AIEE 分子迫切需要进一步发展。因此，本工作设计并合成了一种新型基于黄酮的 AIEE 体系，源于分子内旋转的限制（RIR）。结果表明，其中 6 种化合物表现出典型的 AIEE 特征，通过改变取代基荧光发射从紫色、蓝色、青色到绿色可调。该基于黄酮的 AIEE 体系以前从未报道过。通过光学光谱、荧光照片、扫描电子显微镜（SEM）、CH₃OH/H₂O 混合溶液中的荧光量子产率（Ф）和荧光寿命研究了 AIEE 特性。此外，由于结构简单、分子量小，它们比目前的高分子量 AIEE 分子更快地穿透细胞。此外，为了检验可能的生物医学应用，在活 A549 肺细胞中进行了荧光成像和细胞活力检测，结果表明这些荧光团在实验浓度范围内具有良好的细胞摄取和低细胞毒性。此外，这些 AIEE 化合物对线粒体具有优异的靶向性和线粒体形态变化跟踪特异性，同时还表现出优异的光稳定性，这表明它们是线粒体成像的潜在候选物。
