Organoruthenium and Organoosmium Complexes of 2-Pyridinecarbothioamides Functionalized with a Sulfonamide Motif: Synthesis, Cytotoxicity and Biomolecule Interactions

Anticancer-active Ru^II -η⁶ -p-cymene complexes of bioactive 2-pyridinecarbothioamide ligands have been shown to have high selectivity for plectin and can be administered orally. Reported herein is the functionalization of a 2-pyridinecarbothioamide with a sulfonamide group and its conversion into M-η⁶ -p-cymene complexes (M = Ru, Os). The presence of a sulfonamide moiety in many organic drugs and metal complexes endows these agents with interesting biological properties and can transform the latter into multi-targeted agents. The compounds were characterized with standard methods and the in vitro anticancer activity data was compared with studies on the hydrolytic stability of the complexes and their reactivity to small biomolecules. A molecular modeling study revealed plausible modes of binding of the complexes in the catalytic pocket of carbonic anhydrase II.