Synthesis, characterization, and biological activities of oxovanadium(IV) and cadmium(II) complexes with reduced Schiff bases derived from N,Nʹ-o-phenylenebis(salicylideneimine)

Abstract

New oxovanadium(IV) and cadmium(II) complexes with reduced Schiff bases derived from N,No-phenylenebis(salicylideneimine) have been synthesized and characterized using infrared and UVvisible spectra, ESR, and thermogravimetry. The complexes were identified as [ML] · (H2O) species, where deprotonated ligands are coordinated to metal through N2O2 donor atoms. Antioxidant activity of the ligands and complexes was evaluated, revealing that the complexes exhibit a higher scavenging activity than the corresponding ligands. The prepared cadmium complexes showed slightly higher activity than the vanadium ones. Antifungal activity was tested against different human fungi including yeasts of the Candida genus (C. albicans and C. glabrata) and an opportunistic mould Aspergillus fumigatus. The oxovanadium complexes exhibited a very low activity toward C. albicans while the cadmium ones showed a significant growth inhibition of all the fungi tested; mainly of A. fumigatus though this mould is poorly susceptible to current antifungal agents like Itraconazole.

Computational studies, antimicrobial activity, inhibition of biofilm production, and safety profile of the cadmium complex of 1,10‐phenanthroline and cyanoguanidine

“…Moreover, the [Cd(1-[[3-methyl-pyridine-2-ylimino]methyl]-naphthalen-2-ol)Cl] complex showed significant antioxidant activity against DPPH (IC 50 = 138 μg ml À1 ) and antibacterial properties (judged by the diameters of inhibition zones), 20 like the cadmium (II) complex with reduced Schiff bases derived from N,N 0 -ophenylenebis (salicylideneimine). 21 Other reports of cadmium based compounds proposed antibacterial and antifungal properties employing preliminary screening techniques based on Kirby-Bauer's method. [22][23][24][25][26][27] Few reports of antibiofilm activity of cadmium complexes are available in the literature.…”

“…Six cadmium (II) complexes of a tetradentate Schiff base ligand formulated as CdLX 2 (X = is Cl, Br, I, NO 3 , NCS, or N 3 , and L = (N 2 E,N 2 ′E)‐N1,N1′‐(ethane‐1,2‐diyl)bis(N2‐((E)‐3‐(2‐nitrophenyl)allylidene)ethane‐1,2‐diamine), 17 the series of CdLX 2 (X = Cl − , Br − , I − , SCN − ) complexes with the bis (3[4‐dimethylaminophenyl]‐allylidene)‐1,2‐diaminoethane) Schiff base 18 and [Cd(2,6‐Bis [benzimidazol‐2‐yl]pyridine)Cl 2 ] 19 can be cited as some of the examples in which metal complexation improved the antimicrobial properties of the free ligand. Moreover, the [Cd(1‐[[3‐methyl‐pyridine‐2‐ylimino]‐methyl]‐naphthalen‐2‐ol)Cl] complex showed significant antioxidant activity against DPPH (IC 50 = 138 μg ml −1 ) and antibacterial properties (judged by the diameters of inhibition zones), 20 like the cadmium (II) complex with reduced Schiff bases derived from N , N ′‐ o ‐phenylenebis (salicylideneimine) 21 . Other reports of cadmium based compounds proposed antibacterial and antifungal properties employing preliminary screening techniques based on Kirby‐Bauer's method 22–27 .…”