A Molecular Chameleon with Fluorescein and Rhodamine Spectroscopic Behaviors
A Molecular Chameleon with Fluorescein and Rhodamine Spectroscopic Behaviors
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具有荧光素和罗丹明光谱行为的分子变色龙
DOI：
10.1021/acs.inorgchem.5b02147
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发表时间：
2016-01-04
影响因子：
4.6
通讯作者：
Wong, Keith Man-Chung
中科院分区：
文献类型：
--
作者：
Li, Ling;Wang, Chunyan;Wong, Keith Man-Chung
据报道，一类具有两个螺内酯环的新型荧光素/罗丹明杂化物能够独立地表现出双输出荧光行为。已经对两种非对映异构体反式RhOH 和顺式RhOH 进行了分离和表征，并确定了它们的X 射线晶体结构。在碱性环境中，羟基侧的螺内酯环将打开，产生类似荧光素的光学输出，在 485 和 530 nm 发射处具有最低吸收。另一方面，类罗丹明的光学输出，即 528 nm 吸收和 575 nm 发射，将由 H+ 或 Hg2+ 离子打开，归因于氨基侧螺内酯开环。在不同pH值的甲醇缓冲体系中，羟基和氨基相应的pK(a)值分别确定为5.7和2.3。还讨论了选择性 Hg2+ 传感特性，并确定了 log K-s 值约为 3.60 和 3.73。发现与 RhOH 一起孵育的秀丽隐杆线虫的共焦显微图像显示出 Hg2+ 离子增强的荧光强度，证明了 RhOH 在体内生物成像中的潜在应用。
A new class of fluorescein/rhodamine hybrids with two spirolactone rings was reported to exhibit dual-output fluorescent behaviors independently. Isolation and characterization for two diastereomers, trans-RhOH and cis-RhOH, have been made and their X-ray crystal structures determined. In a basic environment, the spirolactone ring on the hydroxyl side will be opened to give a fluorescein-like optical output with the lowest absorptions at 485 and 530 nm emission. On the other hand, a rhodamine-like optical output, i.e., 528 nm absorption and 575 nm emission, will be switched on by a H+ or a Hg2+ ion, attributed to the spirolactone ring opening on the amino side. In a methanol-buffer system with different pH values, the corresponding pK(a) values for the hydroxyl and amino groups were determined as 5.7 and 2.3, respectively. Selective Hg2+-sensing properties have also been discussed, and log K-s values of about 3.60 and 3.73 were determined. Confocal microscopic images of Caenorhabditis elegans incubated with RhOH were found to show enhanced fluorescent intensity with a Hg2+ ion, demonstrating the potential application of RhOH for in vivo biological imaging.