Acetylenehexacarbonyldicobalt complexes, a novel class of antitumor drugs

Acetylenehexacarbonyldicobalt bait complexes were synthesized and tested fo r antitumor activity. The MCF-7 and MDA-MB-231 mammary tumor cell lines and the LNCaP/FGC prostate carcinoma cell line were used as in vitro models. T he structural evaluation was performed by IR and NMR spectroscopy and revea led a change of the linear acetylene core to a structure comparable to Z-ol efins after coordination to the cobalt centers. In cell culture experiments the strongest effects were found for hexacarbonyl[2-propinylacetylsalicyla te] (10), which was more active than cisplatin on the human mammary tumor c ell lines MCF-7 and MDA-MB-231 in each concentration tested (a 5 mu M conce ntration of this compound even caused cytocidal effects). In contrast to th is, 10 influenced the growth of the LNCaP/FGC cells only marginally, even i n the highest concentration. The mode of action of the complexes tested is unknown. As the cobalt complexes show strong antiproliferative effects and their ligands do not it could be unambiguously demonstrated that complex fo rmation is essential to achieve cytotoxic effects. (C) 2000 Elsevier Scienc e S.A. All rights reserved.