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

Abstract

The present work was aimed that the two Ruthenium compounds namely, [Ru(A) 2 (B)]Cl 2 , where A = 1,10-phenanthroline; B = 2-NO 2 -phenyl thiosemicarbazone (Compound R 1 )/2-OH-phenyl thiosemicarbazone (Compound R 2 ) 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 R 1 exhibited significant antibacterial activity than R 2 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, R 1 exhibited antimalarial activity at 10 µg/mL, whereas R 2 did not show antimalarial activity upto 50 µg/mL. Sensitivity to the compounds was greatest in the gram-negative bacteria, followed by the grampositive bacteria and fungi.

Biological assessment of substituted quinoline based heteroleptic organometallic compounds

“…It is therefore clear that the combination of ruthenium metal and quinoline ligand in a single molecule does produce an improvement of the activity against resistant strains of the parasite, demonstrating the validity of our concept in the search for novel antimalarial drugs capable of overcoming resistance. The IC 50 values of all RuIJIII) complexes are comparable to [Ru III IJL 1-7 ) 3 ]•(PF 6 ) 3 , 11 [Ru(A) 2 (B)]Cl 2 (10 mg L −1 ), 47 [Cu(terpyridyl)Cl]Cl (0.52 μmol L −1 ) and Fe(terpyridyl)Cl 3 (0.63 μmol L −1 ). 48…”

Synthesis of 1,3,5-trisubstituted pyrazoline derivatives and their applications

“…It is thus clear that the combination of ruthenium metal and pyrazolines ligand in a single molecule does produce an enhancement of the activity against resistant strains of the parasite, demonstrating the validity of our concept in the search for novel antimalarial drugs capable of overcoming resistance. The IC 50 values of all Ru(III) complexes are comparable to [Ru(A) 2 (B)]Cl 2 (10 mg mL À1 ), 45 [Cu(terpyridyl)Cl]Cl (0.52 mM), Fe(terpyridyl)Cl 3 (0.63 mM). 46…”

Design, synthesis and biological evaluation of pyrazoline nucleus based homoleptic Ru(iii) compounds

“…It is thus clear that the combination of ru-thenium metal and pyrazoline ligand in a single molecule does produce an activity improvement against resistant strains of the parasite, demonstrating the validity of our concept in the search for novel antimalarial drugs capable of overcoming resistance. The IC 50 values of all RuIJIII) complexes are comparable to [Ru III IJL 1-7 ) 3 ]•(PF 6 ) 3 , 33 [Ru(A) 2 (B)]Cl 2 (10 mg L −1 ), 51 [Cu(terpyridyl)Cl]Cl (0.52 μmol L −1 ) and Fe(terpyridyl)Cl 3 (0.63 μmol L −1 ). 52…”