Imidazole and Azo-Based Schiff Bases Ligands as Highly Active Antifungal and Antioxidant Components

Abstract

We describe, herein, the synthesis, full characterization, and optical properties of four different ligands L1-L4 which associate an azo group, an imidazole unit, and a Schiff base fragment. The UV-visible absorption bands are characteristic of π→π⁎ and n→π⁎ transitions with an additional charge transfer between the azobenzene moiety and the imino group. Finally the determination of MIC80 values against pathogenic fungi such as S. apiospermum, A. fumigatus, and C. albicans revealed that these ligands have effective antifungal properties with highest activities (MIC80) on C. albicans for the azole based ligands L1-L3. DPPH radical scavenging of the studied ligands was also tested.

synthesis and characterization of new imidazole azo ligand with some of transition metal ions, and their biological effect on two pathogenic bacteria of burn patients.

“…Uv-Vis spectrum of free ligand (DPIDA) show up three bands at 284, 257, 238 nm which attributed to (ππ*) transitions of aromatic rings which shifted to higher wavelengths with little changes of values in complexes spectrums , while the bands at 466 nm of (n-π*) transitions that exhibited redshift in the ranges of complexes as a result of charge transfer transitions after coordination as shown in Table 2 . IR spectra of ligand (DPIDA) showed v(N-H) peak of imidazole ring at (3400) cm − (Abbas and Kadhim, 2016)two peeks at (3034) and (3061) cm-due to the vibrations of aromatic v(C-H) , and one peak at (2991) cm-of aliphatic v(C-H) that showed no signi icant changes in the spectra of the complexes frequencies. The peaks at (1588) cm-and (1315) cm-exhibited a stretching of v(C=N) and v(C-N) (Al-Hasani and Almaliky, 2015) respectively of imidazole ring that proceed a changing in position and intensity in complexes which is an indicate the participation of (N3) atom in coordination, also the values of v(N=N) (Jarad et al, 2018); (Slassi et al, 2019b) peak at (1498) cm-shifted to lower values in the complexes that's considered as an evidence on coordination proceed through one nitrogen atom of azo group, new values of v(M-N) frequencies appeared between (543 -511) cm − in the complexes that consider as additional evidence on coordination process as shown inTable 3 andFigures 4, 5 and 6.…”

“…Heterocyclic azo compounds have a lot of scienti ic attention especially in the last ive decades because of their applications in different of applied and academic ields such as Analytical reagents (Khawassek and Mahmoud, 2012), antibacterial (Witwit et al, 2018), antifungal (Slassi et al, 2019a) anticancer (Vernieuwe et al, 2017) and Optical electrical switching of liquid crystals (Oh et al, 2017). Imidazole azo ligands considered as an essential type of heterocyclic azo ligands chie ly in coordination chemistry due to their ability to form stable complexes with metal ions in various of oxidation states (Al-Adilee and Kyhoiesh, 2017), formation of stable ive-member ring with each ion through (N3) atom of imidazole ring and one of nitrogen atoms of azo group (Al-Muhanaa and Al-Khafagy, 2018).…”

New copper(II) and zinc(II) complexes based on azo Schiff base ligand: Synthesis, crystal structure, photoisomerization study and antibacterial activity

“…Schiff base azo ligand L was obtained in good yield (90%) in two steps. The first step was the synthesis of the azo derivative from salicylaldehyde and o ‐toluidine, the second was the formation of Schiff base by the condensation of N ‐(3‐aminopropyl)imidazole with 2‐hydroxy‐5‐( o ‐tolyldiazenyl)benzaldehyde (Scheme ).…”

A review on versatile applications of novel Schiff bases and their metal complexes

“…The Tin (II) chloride complexes with many Schiff base derivative of 2-Hydroxy-1-naphthaldehyde (HN) have been synthesized and screened for their antioxidant activities by DPPH technique. All the complexes showed great antioxidant activities and better antioxidant activities than their corresponding ligands [86][87][88]. Schiff bases of Sulphanilamide and its complexes with elements like Cu, Zn and Cd metals have been tested as an antioxidant.…”