Abstract
In the present work, we report on the synthesis, characterization and biological evaluation of (
E
)-5-(benzyloxy)-2-{[(2,5-dimethoxyphenyl)imino]methyl}phenol Schiff base, C
22
H
21
NO
4
(
BDIMPh
). The compound was synthesized
via
the condensation reaction between 4-benzyloxy-2-hydroxybenzaldehyde and 2,4-dimethoxyaniline. It was characterized using
1
H,
13
C NMR and FT–IR spectroscopies, and its crystal structure was determined by single-crystal X-ray crystallography.
BDIMPh
crystallizes with two crystallographically independent molecules in the asymmetric unit. The structural model also includes the reported disorder features, which are discussed on the basis of the crystallographic refinement. The two molecules of
BDMPh
have the same
E
configuration about the C=N bond. In the crystal, the independent molecules are linked to their inversion-related molecule
via
C—H...O hydrogen bonds. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to quantify the intermolecular contacts present in the crystal. Quantum theory of atoms in molecules (QTAIM) analysis was performed to characterize selected intra- and intermolecular interactions. The optimized geometry showed good agreement with the experimental X-ray crystal structure. The antioxidant activity of
BDIMPh
was evaluated using the DPPH and ABTS radical-scavenging assays.
BDIMPh
exhibited moderate radical-scavenging activity under the experimental conditions and showed higher IC
50
values than the reference antioxidants. The enzyme inhibitory activity of
BDIMPh
was investigated against acetylcholinesterase (AChE), glutathione S-transferase (GST), α-glucosidase and tyrosinase.
BDIMPh
exhibited measurable enzyme-dependent inhibitory activity against AChE, GST and α-glucosidase, whereas comparatively weak inhibition was observed against tyrosinase. The IC
50
values were 2.899 ± 0.851 µ
M
for AChE, 3.850 ± 0.721 µ
M
for GST and 3.284 ± 0.738 µ
M
for α-glucosidase. Compared with the corresponding reference inhibitors,
BDIMPh
showed a slightly higher IC
50
value than donepezil for AChE, a slightly lower IC
50
value than ethacrynic acid for GST and a higher IC
50
value than acarbose for α-glucosidase. These results indicate an enzyme-dependent inhibitory profile rather than uniformly superior activity relative to the reference inhibitors.