Rational design of fluorescein-based fluorescence probes, mechanism-based design of a maximum fluorescence probe for singlet oxygen
Rational design of fluorescein-based fluorescence probes, mechanism-based design of a maximum fluorescence probe for singlet oxygen
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DOI：
10.1021/ja0035708
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发表时间：
2001-03-21
影响因子：
15
通讯作者：
Nagano, T
中科院分区：
文献类型：
--
作者：
Tanaka, K;Miura, T;Nagano, T
黄绿素是生物应用中最好的荧光团之一，但控制其荧光特性的因素尚未完全确定。因此，我们开始了一项研究，旨在提供一个合理的设计具有荧光素结构的功能性荧光探针的策略。我们合成了各种荧光素衍生物，并研究了它们的荧光性质和最高占据分子轨道（HOMO）水平的苯甲酸部分的半经验PM 3计算得到的关系。结果表明，荧光素衍生物的荧光性质受苯甲酸分子到氧杂蒽环的光诱导电子转移（PET）过程控制，苯甲酸分子的HOMO能级的荧光开关阈值约为-8.9eV。这些信息为合理设计功能荧光探针以检测某些生物分子的实用策略提供了基础。我们利用这种方法设计并合成了9-[2-（3-羧基-9，10-二甲基）蒽基]-6-羟基-3H-咕吨-3-酮（DMAX）作为单线态氧探针，并证实它是目前已知的O-1（2）最灵敏的探针。这种新型荧光探针具有9，10-二甲基蒽部分作为O-1的极快化学陷阱（2）。正如从PM 3计算所预期的，DMAX几乎不发荧光;而DMAX内过氧化物（DMAX-EP）是强荧光的。此外，DMAX与O-1（2）的反应速度更快，其灵敏度比我们最近开发的一系列单线态氧荧光探针9-[2-（3-羧基-9，10-二苯基）-蒽基]-6-羟基-3H-咕吨-3-酮（DPAX）高53倍。DMAX可作为荧光探针用于检测各种生物系统中的O-1（2）。
Fluorescein is one of the best available fluorophores for biological applications, but the factors that control its fluorescence properties are not fully established. Thus, we initiated a study aimed at providing a strategy for rational design of functional fluorescence probes bearing fluorescein structure. We have synthesized various kinds of fluorescein derivatives and examined the relationship between their fluorescence properties and the highest occupied molecular orbital (HOMO) levels of their benzoic acid moieties obtained by semiempirical PM3 calculations. It was concluded that the fluorescence properties of fluorescein derivatives are controlled by a photoinduced electron transfer (PET) process from the benzoic acid moiety to the xanthene ring and that the threshold of fluorescence OFF/ON switching lies around -8.9 eV for the HOMO level of the benzoic acid moiety. This information provides the basis for a practical strategy for rational design of functional fluorescence probes to detect certain biomolecules. We used this approach to design and synthesize 9-[2-(3-carboxy-9,10- dimethyl)anthryl]-6-hydroxy-3H-xanthen-3-one (DMAX) as a singlet oxygen probe and confirmed that it is the most sensitive probe currently known for O-1(2). This novel fluorescence probe has a 9,10-dimethylanthracene moiety as an extremely fast chemical trap of O-1(2). AS was expected from PM3 calculations, DMAX scarcely fluoresces; while DMAX endoperoxide (DMAX-EP) is strongly fluorescent. Further, DMAX reacts with O-1(2) more rapidly, and its sensitivity is 53-fold higher than that of 9-[2-(3-carboxy-9,10-diphenyl)-anthryl]-6-hydroxy-3H-xanthen-3-ones (DPAX), which are a series of fluorescence probes for singlet oxygen that we recently developed. DMAX should be useful as a fluorescence probe for detecting O-1(2) in a variety of biological systems.