Cytotoxicity studies of water soluble coordination compounds with a [Mo 2 O 2 S 2 ] 2+ core

Selected molybdenum sulfur compounds with the formulas (M)[Mo2O2S4L] where (Et4N)2(1), L = S42 −, (Et4N)(2), L = Cp, (3), L = DMF, K(5), L = serine, M = Et4N+, K+, Na+ and [Mo2O2S2L2] where Na2(4), L = cysteine, and (6), L = threonine, were prepared and subjected to cytotoxicity studies in vitro. The results were analyzed to rank the compounds according to their relative cytotoxicity and to correlate the observed toxicity to specific composition. The results guide future efforts to synthesize highly water soluble, non-toxic, compounds. Strong correlation was observed between toxicity and cation selection, as well as selection of biocompatible ligands combined with alkali metal salts. The most toxic compound analyzed showed about 50 times less cytotoxicity than the cisplatin reference compound in HT-29 cells. Preliminary results from in vivo data agree with the ranking obtained in vitro.