Synthesis and fluorescence properties of substituted 7-aminocoumarin-3-carboxylate derivatives
Synthesis and fluorescence properties of substituted 7-aminocoumarin-3-carboxylate derivatives
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DOI：
10.1002/jhet.5570370608
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发表时间：
2000-11-01
影响因子：
2.4
通讯作者：
Rettig, W
中科院分区：
文献类型：
--
作者：
Corrie, JET;Munasinghe, VRN;Rettig, W
合成了4-三氟甲基-或6-溴-取代的7-二乙基氨基香豆素-3-甲酰胺衍生物2和3，它们各自含有马来酰亚胺，作为蛋白质中巯基的潜在荧光标记试剂，并测定了它们的荧光性质。4-三氟甲基取代的化合物2具有比缺少该基团的可比较化合物显著更大的斯托克斯位移，但两种新香豆素都具有低荧光量子产率（phi（f））。当存在4-三氟甲基取代基时，3-甲酰胺对水解异常不稳定。溴化7-二乙基氨基香豆素-3-羧酸乙酯17分别得到6-和8-溴衍生物18和19，以及8-溴-7-单乙基氨基化合物20。后一种化合物的phi（f）比其二乙基氨基类似物19大100倍。荧光寿命测量支持基于扭曲分子内电荷转移（TICT）模型的解释，以解释phi（f）的这些大差异。
4-Trifluoromethyl- or 6-bromo-substituted 7-diethylaminocoumarin-3-carboxamide derivatives 2 and 3, each containing a maleimide have been synthesized as potential fluorescent labeling reagents for thiol groups in proteins and their fluorescence properties have been determined. The 4-trifluoromethyl substituted compound 2 has a significantly greater Stokes shift than the comparable compound lacking this group, but both the new coumarins have low fluorescence quantum yields (phi (f)). When a 4-trifluoromethyl substituent is present, the 3-carboxamide is unusually labile to hydrolysis. Bromination of ethyl 7-diethylaminocoumarin-3-carboxylate 17 gave the 6- and 8-bromo derivatives 18 and 19 respectively, and also the 8-bromo-7-monoethylamino compound 20. phi (f) for the latter compound is 100-fold greater than for its diethylamino analogue 19, Fluorescence lifetime measurements support an interpretation based on the twisted intramolecular charge transfer (TICT) model to explain these large differences in phi (f).