Executing a Series of Zinc(II) Complexes of HomologousSchiff Base Ligands for a Comparative Analysis on Hydrolytic, Antioxidant,and Antibacterial Activities
2020
Six
zinc(II) complexes, namely, [Zn(HL1H)Cl2] (1), [Zn(HL1H)Br2] (2),
[Zn2(HL1H)2(OH)I2]·I
(3), [Zn(HL2)Cl] (4), [Zn2(HL2)Br3] (5), and [Zn(HL2)I] (6) have been manufactured by using two homologous
Schiff base ligands H2L1 and H2L2 for the purpose of
perlustrating their phosphatase-like activity, antioxidant activity,
and antibacterial activity. Complexes 1, 2, 4, and 5 have been reported earlier by
us, whereas complexes 3 and 6 have been
synthesized and structurally characterized by regular physicochemical
methods The hydrolytic property of the six complexes has been evaluated
by checking the hydrolysis of the P–O bond of a widely used
substrate, namely, disodium salt of (para-nitrophenyl)phosphate
(PNPP) in 97.5% (v/v) mixture of N,N-dimethylformamide and water (DMF–water). Complexes 2–5 have profound efficiency toward hydrolysis of phosphate
ester bonds, and complexes 1 and 6 were
noted to be inactive toward hydrolysis. Complex 3 displayed
the highest efficacy among the six complexes. Additionally, antioxidant
and antibacterial activities of the complexes were studied thoroughly.
A detailed study of their antioxidant property revealed that complex 3 manifested superior radical scavenging activity, thus exhibiting
the highest antioxidant property. The antibacterial activity was tested
using four investigating bacteria, specifically Listeria
monocytogenes ATCC19111, Staphylococcus
aureus ATCC 700699, Salmonella typhimurium ATCC 23564, and Escherichia coli ATCC
25922 by determining minimum inhibitory concentration (MIC) values
using the microdilution method. Here as well, complex 3 exhibited the highest activity to both Gram positive and Gram negative
bacteria. The chemistry behind these experimental findings has been
manifested by shedding light upon the structural features of the complexes.
The suitable choice of ligand H2L1 where one
methylene group is less than its homologous ligand and metal precursor
(ZnI2) imparts a unique hydroxo-bridged molecular geometry
and 2D hydrogen bonding network which in turn probably enhances the
hydrolytic and biological activities of complex 3.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
53
References
1
Citations
NaN
KQI