A library of 32 organoruthenium compounds has been synthesised. Known and novel C-N cyclometalated compounds as well as N-C-N and N-N-C pincer derivatives of this metal have been used in this purpose. Most of the compounds have been tested for their in vitro antitumoral behaviours, good to excellent activities have thus been found. Several of the newly synthesized compounds pass the symbolic barrier of the nanomolar range for their IC(50) indicating a critical improvement. The level of activity is tentatively correlated to physicochemical properties of the compounds such as their Ru(III/II) redox potential and their lipophilicity (log P).

Human 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) catalyzes the reduction of the weak estrogen estrone (E1) to the highly potent estradiol (E2). This reaction takes place in the target cell where the estrogenic effect is exerted via the estrogen receptor (ER). Estrogens, especially E2, are known to stimulate the proliferation of hormone-dependent diseases. 17beta-HSD1 is overexpressed in many breast tumors. Thus, it is an attractive target for the treatment of these diseases. Ligand- and structure-based drug design led to the discovery of novel, selective, and potent inhibitors of 17beta-HSD1. Phenyl-substituted bicyclic moieties were synthesized as mimics of the steroidal substrate. Computational methods were used to obtain insight into their interactions with the protein. Compound 5 turned out to be a highly potent inhibitor of 17beta-HSD1 showing good selectivity (17beta-HSD2, ERalpha and beta), medium cell permeation, reasonable metabolic stability (rat hepatic microsomes), and little inhibition of hepatic CYP enzymes.