Telomerase is the enzyme responsible for extending G-strand telomeric DNA and represents a promising target for neoplasia therapeutic treatments.Inhibition of telomerase can be achieved by stabilization of G-quadruplex DNA structures. Here we characterized a novel compound,3,6-bis (4 -methyl-2-vinylpyrazinium) carbazole diiodine ( BMVC4). that stabilized G-quadruplex structure and inhibited telomerase activity in vitro.