Synthesis of E -stilbene azomethines as potent antimicrobial and antioxidant agents

Abstract

A series of new extensively conjugated E-stilbene azomethines (5a-5h) were synthesized and screened for their antioxidant and antimicrobial activity. The compounds were tested against bacterial (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis) and fungal strains (Aspergillus niger, A. flavus, and Trichoderma harzianum) using the agar well diffusion method. Among the tested compounds, N '-(4-nitrobenzylidene)-2-((E)-styryl)benzohydrazide (5g) was found to possess potent antimicrobial activity higher than some drugs with significant activity reported in the literature, e.g., cefradine and terbinafine hydrochloride. Additionally, compounds 5a-5h were also evaluated for antioxidant potential using DPPH free radical scavenging and ferric thiocyanate (FTC) assays. Among these, N '-(4-hydroxybenzylidene)-2-((E)-styryl)benzohydrazide (5e) exhibited significant antioxidant potential by both assays. Compound 5e demonstrated higher DPPH free radical scavenging activity (IC 50 = 22 ± 0.19 µ g/mL) than the standard, butylated hydroxytoluene (BHT; IC 50 = 28 ± 0.10 µ g/mL). A similar trend was observed for compound 5e in FTC assay, which exhibited 86 ± 0.19% inhibition, whereas the BHT control showed 81 ± 0.21% inhibition of linoleic acid peroxidase. The structure elucidation of the synthesized compounds was carried out by UV-Vis, FT-IR, 1 H NMR, 13 C NMR, and elemental analysis and mass spectrometry. These results suggest possible use of these compounds for the rational design of new antimicrobial and antioxidant agents.

Green Synthesis of Gold and Silver Nanoparticles Using Leaf Extract of Clerodendrum inerme; Characterization, Antimicrobial, and Antioxidant Activities

“…The green synthesized CI-Au NPs, and CI-Ag NPs were assessed for their antimycotic activity against three pathogenic fungal strains ( Aspergillus niger , Aspergillus flavus , and Trichoderma harzianum ) using the standard agar well diffusion assay [ 22 ]. In a typical procedure, a freshly prepared autoclaved solution of potato dextrose (25 mL) was transferred to autoclaved petri dishes.…”

Synthesis, DFT, computational exploration of chemical reactivity, molecular docking studies of novel formazan metal complexes and their biological applications

“…These bacteriological strains were acquired from Pakistan Chemical Scientific Industrial Research (PCSIR) laboratories complex, Lahore, Pakistan. The bactericidal propensity of synthesized metal complex formazans (S1‐S6) was deliberated on agar plates by well‐known agar well diffusion method as described by . For each type of microbial species, the streptomycin and neomycin were employed as a standard antibiotic drug (positive control) …”

In silico and in vitro evaluation of the biological activity of some organicsulfur-containing compounds

“…Antioxidants protect organisms from highly reactive free radicals, especially ROS, which are capable of oxidizing biomolecules, causing different human diseases [16]. The search for novel antioxidant agents that prevent or reduce the impact of oxidative stress on cells is a topical scope.…”