Synthesis and spectral-luminescent studies of novel 4-oxo-4,6,7,8-tetrahydropyrrolo[1,2-a]thieno[2,3-d]pyrimidinium styryls as fluorescent dyes for biomolecules detection

A series of novel 4-oxo-4,6,7,8-tetrahydropyrrolot 1,2-a]thieno[2,3-d]pyrimidinium and 5-oxo-1,2,3,5-tetrahydropyrrolo[2,1-b]quinazolinium styryl dyes were synthesized. For preparing of studied dyes the standard. method of styrylcyanines synthesis was modified. Spectral-luminescent properties of obtained dyes in free state and in the presence of nucleic acids and BSA were studied. It was shown that p-dimethylaminostyryls based on 4-oxo-4,6,7,8-tetrahydropyrrolo[1,2-a]thieno[2,3-d]pyrimidinium with aliphatic substituents in 2 and 3 positions demonstrated RNA-binding preference. These dyes in the presence of RNA significantly enhance emission intensity and could be used as RNA-specific fluorescent probes. Besides, the fluorescence emission after two-photon absorption of dye-RNA complexes in buffer solutions was measured. (C) 2006 Elsevier Ltd. All rights reserved.