GRAPHICS
A new class of shape-modified nucleosides is introduced. The purine heterob
ases of adenosine and guanosine have been split into their imidazole and py
rimidine components, thereby introducing flexibility while retaining the el
ements necessary for recognition. As a consequence, these novel "fleximers"
should find use as bioprobes for investigating enzyme-coenzyme binding sit
es as well as nucleic acid and protein interactions. Their design and synth
esis is described.