Antimicrobial and Antimalarial Activity of Novel Synthetic Mononuclear Ruthenium(II) Compounds

The present work was aimed that the two Ruthenium compounds namely, Ru(A)₂(B)]Cl₂, where A = 1,10‐phenanthroline; B = 2‐NO₂‐phenyl thiosemicarbazone (Compound R₁)/2‐OH‐phenyl thiosemicarbazone (Compound R₂) have been tested for antibacterial activity at the concentrations of 1 mg/mL against various Gram‐Positive organisms (Lactobacillus, Staphylococcus pyrogenes, Bacillus subtilis, Staphylococcus aureus & Bacillus megatarium) and Gram‐Negative organisms (Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Enterobacter aerogenes, Salmonella paratyphi, Klebsiella pneumonia & Proteus mirabilis). The compounds were also tested for antifungal activity against Aspergillus clavatus, Aspergillus niger, Colletotrichum & Penicillium notatum by using agar diffusion assay and antimalarial activity against Plasmodium falciparum (Strain 3D7) using MTT assay. The results concluded that the compound R₁ exhibited significant antibacterial activity than R₂ against Gram‐Negative bacteria with zones of inhibition ranging from 15‐20 mm. and mild antibacterial activity against Gram‐Positive bacteria in comparison to tetracycline, streptomycin and rifampicin. These complexes were found to have moderate antifungal activity with no activity was however observed against Aspergillus niger. The compound, R₁ exhibited antimalarial activity at 10 μg/mL, whereas R₂ did not show antimalarial activity upto 50 μg/mL. Sensitivity to the compounds was greatest in the gram‐negative bacteria, followed by the gram‐positive bacteria and fungi.