Bis(diphenylphosphino)amines-containing ruthenium cymene complexes as potential anti-Mycobacterium tuberculosis agents.

Several ruthenium complexes have been investigated regarding anti-Mycobacterium tuberculosis (anti-MTb) activity, with some diphosphine-containing ruthenium complexes comparable to first and second line drugs. However, to the best of our knowledge, there is no PNP-containing ruthenium complexes applied as metallodrugs. Thus, this study focused on the synthesis, characterization and anti-MTb activity of a new series of coordination compounds with general formula [RuCl(η6 -p-cymene)(PNR P)]X (R=CH2 Py (Py=pyridine)-[1a], CH2 Ph (Ph=phenyl)-[1b], Ph-[1c] and p-tol (p-tol=p-tolyl)-[1d]; X=PF6 - or BF4 - ). The complexes were fully characterized by NMR (1 H,31 P{1 H}), vibrational spectroscopy (FTIR), ESI-MS, molar conductance, elemental analysis and X-ray diffraction studies. The molecular structures of [1a]PF6 , [1c]BF4 and [1d]PF6 were determined and confirm the spectroscopic and ESI-MS data. The complexes were used in anti-MTb trials, and the preliminary results are presented. The complexes are promising anti-MTb agents with MIC90 (Minimum Inhibitory Concentration of compounds required to inhibit the growth of 90% of MTb) values comparable with the Ethambutol, the reference drug used in this work, and complex [1a]BF4 presented the highest selectivity index.