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 (Delta lambda(em)(max) = 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. (C) 2010 Elsevier Ltd. All rights reserved.