Synthesis, Characterization and Antimycobacterial Activity of Phenanthrenequinone Thiosemicarbazones and their Ruthenium and Zinc Complexes

The substituted phenanthrenequinone thiosemicarbazones (HL1, HL2 and HL3), and their metal complexes (M = Ru(II) or Zn(II); SM1, SM2, SM3 and SM4) were synthesized and characterized by FT-IR, 1H & 13C NMR and ESI-MS. The spectral data IR, 1H & 13C NMR and ESI-MS indicates two tridentate ligands coordinating in the form of an octahedral geometry. The gas phase geometry of all the zinc(II) and ruthenium(II) complexes was carried by using density functional theory (DFT). The antimycobacterial susceptibility testing at 100 μM of the complexes using resazurin microtiter plate assay resulted in growth inhibition. Complexes SM2, SM3 and SM4 showed good antimycobacterial activity at 100 μM concentration by using rifampicin as inhibition control.