Promising Antimicrobial Activity of an Oxime Based Palladium(II) Complex

Abstract

This work delineates with the development of a novel oxime based palladium complex as a promising antimicrobial agent. A novel oxime based ligand, 3-[(2-hydroxy-naphthalen-1-ylmethylene)-hydrazono]-butan-2-one oxime (LH), has been employed to synthesize an orange, monomeric, diamagnetic palladium(II) compound, [Pd(L)(Cl)] (1) in moderate yield. LH is a monocondensate Schiff-base of 2,3-butanedionemonoxime monohydrazone and 2-hydroxy-1-naphthaldehyde in tetrahydrofuran. Both the ligand and its palladium compound have been characterized by spectroscopic and analytical techniques. The X-ray crystal structure of 1 reveals that the palladium center in [Pd(L)(Cl)] is nested in a distorted square-planar 'N 2 OCl' coordination environment. The electrochemical behavior of [Pd (L)(Cl)] in DMF shows a Pd(II)/ Pd(I) irreversible reduction couple. The in vitro antibacterial activity of [Pd(L)(Cl)] was tested against a good number of human pathogenic Grampositive and Gram-negative bacterial cell lines. The in vitro antifungal activity of the titled palladium compound was screened against several pathogenic fungal strains. The promising antimicrobial efficacy of the palladium compound was corroborated through SEM study.

Metal‐Based Nanomaterials in Biomedical Applications: Antimicrobial Activity and Cytotoxicity Aspects

“…[ 242 ] A novel oxime‐based Pd (II) complex has been shown to possess potent antibacterial activities against Gram‐positive and Gram‐negative bacteria that are pathogenic to humans. [ 243 ] Nanostructured Pd‐loaded silicon carbide nanoparticles have been successfully synthesized that are antibacterial against E. coli and S. aureus . [ 244 ] More recently, bidentate pyridine‐functionalized Pd N‐heterocyclic carbene complexes with various wingtip substituents (R = methyl, phenyl, and tert ‐butyl) have been synthesized and evaluated for their potential biomedical applications as antimicrobials and antiproliferative drug candidates.…”

Pd(ii) and Pt(ii) complexes of tridentate ligands with selective toxicity against Cryptococcus neoformans and Candida albicans

“…On comparing with some of the previously published complexes of L PY and L BZ , complexes 1 and 2 displayed higher antifungal activities than triazolate-Mn(CO) 3 of L PY , which was potent against C. albicans and C. neoformans (MIC ¼ 6.0 mM). 41 Besides, compounds 1 and 2 exhibited higher potency against the same two pathogens than the Pd(II) sulfonate and Pt(II) phosphonium complexes of benzimidazole ligands (MIC ¼ 2-30 mM) we reported earlier 7 and a morpholine-based Pd(II) complex (MIC ¼ 32-64 mM), 42 while displaying comparable antifungal activity to other benzimidazole Pd(II) complexes (MIC ¼ 500-2 mg mL À1 ), 43,44 an oxime Schiff-base (MIC ¼ 500 mg mL À1 ), 45 and thiosalicylic acid (MIC ¼ 1000-62 mg mL À1 ). 46 Based on the interesting antifungal properties of 1 and 2 against C. neoformans, further evaluation of these two compounds and other closely related structures as antifungal agents is highly recommended (Table 2).…”

Synthesis and Chelating Behaviour of Multidentate Ligand With Some Transition Metal(II) Ions

“…This band remains almost intact in the IR spectra of complexes indicating its non-involvement in coordination. The strong band at 1640 cm -1 in the spectra of free ligand is fairly assigned to ν(C=N), azomethine group stretching vibration [36,37]. In the spectra of all the metal complexes, this band gets shifted to 1615-1605 cm -1 which shows azomethine nitrogen is involved in coordination to metal ion [38,39].…”