Organometallic tosyl hydrazones: Synthesis, characterization, crystal structures and in vitro evaluation for anti-Mycobacterium tuberculosis and antiproliferative activities

A series of new organometallic tosyl hydrazones of the general formula [{(η⁵-C₅H₄)-C(R) = NNHSO₂C₆H₄CH₃}]M(CO)₃ (M = Re, Mn; R = H, CH₃) were prepared by the reaction between formyl or acetyl organometallic precursors with p-toluenesulfonyl hydrazide. All compounds were characterized by conventional spectroscopic techniques (infrared, ¹H and ¹³C NMR, mass spectrometry and elemental analysis). In addition, the molecular structures of the cymantrenyl hydrazones 2a and 2b have been determined by single-crystal X-ray diffraction. In the solid state, both compounds showed an E-configuration around the C[dbnd]N moiety. Evaluation of antitubercular activity, measured in vitro against Mycobacterium tuberculosis mc²6230 strain, indicate that all organometallic tosyl hydrazones are considerably less active than the reference drug isoniazid. The antiproliferative activity against non-small cell lung cancer cells (H1299 cells) was also evaluated. Even though the IC₅₀ measured for hydrazones 1–3 resulted 2–3-fold higher than cisplatin, biological results demonstrate that the electronic effects of the substituents on the hydrazone carbon are influencing factor in the anticancer activity.