Kenmoku Suguru, Urano Yasuteru, Kojima Hirotatsu, Nagano Tetsuo
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
J Am Chem Soc. 2007 Jun 13;129(23):7313-8. doi: 10.1021/ja068740g. Epub 2007 May 17.
The tetramethylrhodamine (TMR) fluorophore is a useful platform for fluorescence probes, being applicable, for example, to biological investigations utilizing fluorescence microscopy, owing to its excellent photochemical properties in aqueous media. We have developed new TMR derivatives that show different dependences of their behavior upon the environment. Among them, HMTMR showed unique characteristics, and its putative spirocyclic structure was confirmed by X-ray crystallography. Utilizing this discovery, we have established a strategy to modulate the fluorescence of TMR by regulating the spirocyclization, and we have obtained a new fluorescence probe that can detect hypochlorous acid specifically. This probe, HySOx, can work in 99.9% aqueous solution at pH 7.4 and was confirmed to be able to detect hypochlorous acid being generated inside phagosomes in real time. HySOx is tolerant to autoxidation and photobleaching under bioimaging conditions. Regulation of the spirocyclization of rhodamines, as we describe here, provides a new approach to the rational development of novel fluorescence probes.
四甲基罗丹明（TMR）荧光团是荧光探针的一个有用平台，例如，由于其在水性介质中具有优异的光化学性质，可应用于利用荧光显微镜进行的生物学研究。我们开发了新的TMR衍生物，它们在行为上对环境表现出不同的依赖性。其中，HMTMR表现出独特的特性，其假定的螺环结构通过X射线晶体学得到证实。利用这一发现，我们建立了一种通过调节螺环化来调节TMR荧光的策略，并获得了一种能够特异性检测次氯酸的新型荧光探针。这种探针HySOx可以在pH 7.4的99.9%水溶液中起作用，并被证实能够实时检测吞噬小体内产生的次氯酸。HySOx在生物成像条件下耐受自氧化和光漂白。如我们在此所述，罗丹明螺环化的调节为合理开发新型荧光探针提供了一种新方法。
