TITLE:
Synthesis, Characterization and Antibacterial Activities of Polydentate Schiff Bases, Based on Salicylaldehyde
AUTHORS:
Yosef Bayeh, Fekiya Mohammed, Mamo Gebrezgiabher, Fikre Elemo, Mesfin Getachew, Madhu Thomas
KEYWORDS:
Schiff Bases, Salicyaldehyde, Antibacterial Activity, In-Vitro
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.10 No.5,
October
21,
2020
ABSTRACT: Three Schiff bases L1, L2 and L3 were
synthesized by condensing salicylaldehyde
with 4-aminoantipyrine, ethylendiamine and 2-aminophenol respectively
and subsequently characterized by various physicochemical investigations. All
the three compounds were screened for their In-vitro antibacterial activity against two gram positive bacteria, Staphylococcus
aureus (S.A), Staphylococcus epidermidis (S.E) and two gram negative
bacteria Klebsiella pneumoniae (K.P) and Pseudomonas aeruginosa (P.A) by
agar diffusion method. On comparing the results obtained with the activity of
commercially available antibiotics such as Ciprofloxacin and Chloramphenicol,
the newly synthesized compounds showed comparable antibacterial activities. The
solvent methanol exhibit activity against all bacterial species with IZs
ranging from 8 ± 0.25 to 17 ± 0.29 mm while the standard antibiotics
Ciprofloxacin and Chloramphenicol exhibited an activities with IZs varying from
21.3 ± 0.31 to 28.3 ± 0.32 and 26.3 ± 0.24 mm to 32.3 ± 0.23 mm, respectively.
However, the newly synthesized Schiff bases L1, L2 and L3 showed IZs ranging from 7.4 ± 0.23 to 32.5 ± 0.14, 3 ± 0.57 to 12 ± 0.28 and 10
± 0.20 to 32 ± 0.36 respectively. Among the Schiff bases, L3 showed
the activity (32 ± 0.36) against S.E and P.A which
is higher than the activity of standard antibiotics Ciprofloxacin and Chloramphenicol against the same bacterial strains. The results obtained
revealed that all the synthesized Schiff bases exhibit appreciable
antibacterial activity against all the bacteria species which potentially makes
them, to apply as wide range antibacterial drugs, after further in-vivo cytotoxicity investigations. Their activity can also be further modified by
changing the functionality of precursors for Schiff base condensation.