The antiparasitic activity and the cytotoxicity of intermediated 2-4 was discussed formerly . From the diruthenium alkyne intermediates 5-8, only derivative 5 presented reduced toxicity on HFF at 1 µM, while amide 8 affected HFF viability even at 0.1 µM. Unlike compound 6, amide 5 exhibited an improved HFF toxicity and antiparasitic efficacy profile compared to the amino diruthenium precursor 2. Ester 7 and amide 8 affected more the proliferation of T. gondii β-gal than the carboxy precursor 3 but also exerted a stronger effect on the host cells viability at 1 µM. Both diruthenium azides 9 and 10 exhibited high activity against the parasite even at 0.1 µM but were toxic to HFF at 1 µM.