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

1)结合新型荧光生物传感器的开发，合成了几种4-芳基亚甲基-5-咪唑啉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-甲氧基-2-萘甲醛为起始原料，2-（二甲基氨基）苯甲醛和1-芘甲醛，我们可以制备1，2-二甲基-4-（2-萘基亚甲基）-5-咪唑酮，1，2-二甲基-4-（6-甲氧基-2-萘基亚甲基）-5-咪唑酮，1，2-二甲基-4-[4-（二甲基氨基）苯基亚甲基]-5-咪唑酮和1，2-二甲基-4-（1-芘基亚甲基）-5-咪唑酮。结果表明，所合成的化合物在溶液中的荧光强度很弱，而在77 ° K下的乙醇玻璃基质中的荧光强度为2000 ~ 3000倍。2-萘基衍生物的荧光最大值为520 nm，6-甲氧基-2-萘基衍生物的荧光最大值为460 nm，4-甲氧基-2-萘基衍生物的荧光最大值为520 nm。（二甲基氨基）苯基衍生物，1-芘基衍生物在503 nm处有较强的荧光发射。2）我们尝试合成了具有金属螯合功能团的4-亚芳基-5-咪唑啉酮衍生物，得到了1-甲基-4-[（3-溴苯基）亚甲基]-2-（3-溴苯基）-5-咪唑酮，能够引入螯合基团。咪唑酮衍生物与吗啉在Pd（0）催化剂存在下反应，得到相应的吗啉代衍生物。3）为了研究GFP发色团的荧光性质，我们采用GFP发色团模型咪唑啉酮衍生物研究了荧光寿命与溶剂粘度的关系。结果，GFP发色团的荧光寿命随着所用溶剂的粘度增加而延长。

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.