Development of Fluorescent ON/OFF Mode Biosensor Based on GFP Chromophore

1)结合基于GFP荧光发色团的新型荧光生物传感器的开发，合成了几种具有4-芳亚甲基-5-咪唑酮结构的先导化合物，并研究了它们的荧光性质。以2-萘甲醛、6-甲氧基-2-萘甲醛、4-二甲氨基苯甲醛和1-丙叉醛为原料，利用半乳酸埃伦迈尔法合成了1，2-dimethyl-4-(2-naphthylmethylidene)-5-imidazolone，，2-二甲基-4-(6-甲氧基-2-萘亚甲基)-5-咪唑酮、1，2-dimethyl-4-[4-(dimethylamino)phenylmethylidene]-5-imidazolone，和1，2-dimethyl-4-(1-pyrenylmethylidene)-5-imidazolone。我们发现所有的化合物在溶液状态下都表现出很弱的荧光性能，而在77°K下，它们在乙醇玻璃基质中表现出2000~3000倍的强荧光，最大荧光波长分别为520 nm，460 nm，460 nm，520 nm，503 nm。2)我们尝试合成了具有金属螯合官能团的4-亚芳基-5-咪唑酮衍生物，得到了1-methyl-4-[(3-bromophenyl)methylidene]-2-(3-bromophenyl)-5-imidazolone，。能够引入螯合基团。咪唑酮类化合物与吗啉在Pd(0)催化剂存在下反应得到相应的吗啉类化合物。3)为了研究GFP发色团的荧光性质，我们利用GFP生色团模型咪唑酮衍生物研究了荧光寿命与溶剂粘度之间的关系。结果表明，GFP发色团的荧光寿命随所用溶剂粘度的增加而延长。

1) In connection with the development of new fluorescent biosensor based on GFP fluorescent chromophore several lead compounds with a 4-arylmethylidene-5-imidazolone structure were prepared and their fluorescence properties were investigated. Starting with 2-naphthalenecarboxaldehyde, 6-methoxy-2-naphthalenecarboxaldehyde, 4-(dimethylamino)benzaldehyde, and 1-pyrenecarboxaldehyde, we could prepare 1,2-dimethyl-4-(2-naphthylmethylidene)-5-imidazolone, 1,2-dimetnyl-4-(6-methoxy-2- naphthylmethylidene)-5-imidazolone, 1,2-dimethyl-4-[4-(dimethylamino)phenylmethylidene]-5-imidazolone, and 1,2-dimethyl-4-(1-pyrenylmethylidene)-5-imidazolone by utilizing Erlenmeyer ablactate method. We found that all compounds prepared exhibited very weak fluorescent properties in solution state, whereas they showed 2000〜3000 times strong fluorescence in ethanol glass matrices at 77 ° K. Fluorescence maximums were 520 nm for the 2-naphthyl derivative, 460nm for the 6-methoxy-2-naphthyl derivative, 520 nm for the 4-(dimethylamino)phenyl derivative, and 503 nm for the 1-pyrenyl derivative.2) We attempted to prepare the 4-aryliden-5-imidazolone derivative having metal-chelating functional groups and we could obtained 1-methyl-4-[(3-bromophenyl)methylidene]-2-(3-bromophenyl)-5-imidazolone, being able to introduce chelating groups. Reaction of the imidazolone derivatives with morpholine in the presence of a Pd(0) catalyst afforded the corresponding morpholino derivative. Introduction of a Ca-chelating functional group is under investigation.3) For studying fluorescence properties of the GFP chromophore, we investigated the relationship between fluorescence life times and solvent viscosities by using a GFP chromophore model imidazolone derivative. As results, the fluorescence lifetime of the GFP chromophore was prolonged with increasing the viscosity of the solvent used.