Design and synthesis of highly solvatochromic fluorescent 2'-deoxyguanosine and 2'-deoxyadenosine analogs.

We synthesized various substituted 8-styryl-2'-deoxyguanosine and 8-styryl-2'-deoxyadenosine derivatives. Among them only acetyl substituted 8-styryl-2'-deoxyguanosine analog 5b showed a remarkable solvatochromicity (Δλ(max)(em)=91 nm),that is, strong fluorescence at 477 nm in 1,4-dioxane, but in methanol the fluorescence was red shifted to 558 nm with very low intensity. Such environmentally sensitive solvatochromic fluorescent guanosine analogs may be useful as a sensor for investigating interactions of DNA with DNA binding proteins.