Zinc (II) cyclen–peptide hybrid compounds and bis-zinc (II) cyclen complexes are prepared as potential binders of the guanine nucleotide binding protein Ras, an important molecular switch in cellular signal transduction. The design of the compounds is based on the previous observation that zinc (II) cyclen complexes could serve as lead compounds for inhibitors of Ras-effector interaction and thus be able to interrupt Ras induced signal transduction. Zinc ...