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

Authors : Ahsan IQBAL, Zulfiqar Ali KHAN, Sohail Anjum SHAHZAD, Muhammad USMAN, Shakeel Ahmad KHAN, Abdul H FAUQ, Ayesha BARI, Muhammad Aamir SAJID

Pages : 1518-1533

View : 15 | Download : 6

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A series of new extensively conjugated $E$-stilbene azomethines insert ignore into journalissuearticles values(5a-5h); were synthesized and screened for their antioxidant and antimicrobial activity. The compounds were tested against bacterial insert ignore into journalissuearticles values(Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis); and fungal strains insert ignore into journalissuearticles values(Aspergillus niger, A. flavus, and Trichoderma harzianum); using the agar well diffusion method. Among the tested compounds, $N$`-insert ignore into journalissuearticles values(4-nitrobenzylidene);-2-insert ignore into journalissuearticles values(insert ignore into journalissuearticles values($E);$-styryl);benzohydrazide insert ignore into journalissuearticles values(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 insert ignore into journalissuearticles values(FTC); assays. Among these, $N$`-insert ignore into journalissuearticles values(4-hydroxybenzylidene);-2-insert ignore into journalissuearticles values(insert ignore into journalissuearticles values($E);$-styryl);benzohydrazide insert ignore into journalissuearticles values(5e); exhibited significant antioxidant potential by both assays. Compound 5e demonstrated higher DPPH free radical scavenging activity insert ignore into journalissuearticles values(IC$_{50} = 22 \pm 0.19 \mu$ g/m); than the standard, butylated hydroxytoluene insert ignore into journalissuearticles values(BHT; IC$_{50} =28 \pm 0.10 \mu$ g/mL);. A similar trend was observed for compound 5e in FTC assay, which exhibited 86 $\pm$ 0.19% inhibition, whereas the BHT control showed 81 $\pm$ 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.
Keywords : E Stilbenes, azomethine analogues, Mizoroki Heck reaction, antimicrobial activity, antioxidant activity