Covalent analogues of DNA base-Pairs and triplets. Part 2: Synthesis and cytostatic activity of bis(purin-6-yl)acetylenes,-diacetylenes and related compounds

The title bis(purin-6-yl)acetylenes, -diacetylenes, -ethylenes and -ethanes were prepared as covalent base-pair analogues starting from 6-ethynylpurines and 6-iodopurines by cross-coupling and homo-coupling reactions and hydrogenations. The bis(purin-6-yl)acetylenes and -diacetylenes exhibited significant cytostatic activity in vitro (IC50=0.4–1.0 μmol/l).