Synthesis and biological evaluation of 6-hydroxychromone based thiosemicarbazones as potential antidiabetic and antioxidant agents

Abstract

A new series of 6-hydroxychromone-based thiosemicarbazones 4(a-p) was synthesized and assessed for their antidiabetic (α-Glucosidase and α-Amylase inhibition) as well as antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)) activities. Among the synthesized compounds, compound 4k (IC₅₀ = 1.18 ± 0.19 µg/mL) emerged as the promising α-Glucosidase inhibitor, significantly outperforming the reference drug Acarbose (IC₅₀ = 7.33 ± 0.13 µg/mL). For α-Amylase inhibition, compound 4 g (IC₅₀ = 13.61 ± 2.04 µg/mL) demonstrated excellent activity, compared to Acarbose (IC₅₀ = 43.15 ± 5.22 µg/mL). In antioxidant assays, compound 4o (IC₅₀ = 15.30 ± 1.70 µg/mL) exhibited the strongest DPPH radical scavenging effect, and compound 4 g (IC₅₀ = 6.06 ± 0.15 µg/mL) showed the highest ABTS scavenging activity, surpassing the standard antioxidant Trolox (IC₅₀ = 30.20 ± 5.14 & 18.19 ± 2.47 µg/mL, respectively). Remarkably, these derivatives showed greater efficacy compared to standard inhibitors, underscoring their promise as novel candidates for antidiabetic and antioxidant drug development. Molecular docking analysis demonstrated strong binding and critical interactions within the enzyme active sites. MD simulations confirmed the stability of 4k-α-Glucosidase and 4 g-α-Amylase, with RMSD values below 3.6 Å, low RMSF (< 2.8 Å) at the binding site, and sustained key interactions with Phe 158 and Tyr 151, respectively. The network pharmacology further supported the findings of molecular docking and simulation analysis.

Supplementary Information: The online version contains supplementary material available at 10.1038/s41598-026-40449-y.

Keywords: 6-Hydroxychromone; Antidiabetic; Antioxidant; Enzyme inhibition; Molecular docking; Thiosemicarbazones.

Fig. 1

Representative chromone and thiosemicarbazone scaffolds previously reported for enzyme inhibition and antioxidant activity.

Scheme 1

Synthetic route of Chromone-based thiosemicarbazones 4(a-p).

Fig. 2

(A) IC₅₀ graphs of the best inhibitors for α-Glucosidase (B) IC₅₀ graphs of the best inhibitors for α-Amylase.

Fig. 3

IC₅₀ results of the antioxidant for two assays (ABTS and DPPH).

Fig. 4

Pictorial representation of SAR.

Fig. 5

(A) Docked conformations of compounds 4(a-p) aligned in the α-Glucosidase binding site. The docked conformation of Acarbose is demonstrated in black. (B) Common amino acids in the active site interact with the inhibitors.

Fig. 6

A view of binding site contacts of 4k in the active site of α-Glucosidase.

Fig. 7

A view of binding site contacts of 4c (with and without surface representation) in the of α-Glucosidase’s active site.

Fig. 8

Overlap of docked conformation of α-Amylase inhibitor 4 g with co-crystallized inhibitor (represented in black).

Fig. 9

A view of binding site contacts of 4 g (with and without surface representation) in the active site of α-Amylase.

Fig. 10

MD simulation studies of 4k-α-Glucosidase complex for 100ns, RMSD graph, Protein RMSF graph, Ligand RMSF graph, and protein ligand contacts of α-Glucosidase with 4k.

Fig. 11

Protein-Ligand Contacts, and Torsional Profile of 4k-α-Glucosidase complex.

Fig. 12

MD simulation analysis of 4 g-α-Amylase complex for 100ns, RMSD plot, Protein RMSF graph, Ligand RMSF graph, and protein ligand 4g-α-Amylase contacts.

Fig. 13

Ligand-Protein Contacts, and Ligand Torsion Profile of 4g-α-Amylase.

Fig. 14

The Venn analysis: Panel (A) represents 65 predicted genes from DIGEP-Pred (p > 0.5), and Panel (B) depicts 181 targets retrieved from GeneCards (GIFt score > 65).

Fig. 15

A schematic representation of Network pharmacology highlighting Compound-Target (C-T) and Target-Pathway (T-P) interactions. Compounds, Targets, and Pathway Ids are colored as green, brown, and cyan, respectively.

Fig. 16

The GO-enrichment analysis: (A) Biological processes, (B) Cellular Functions, (C) Molecular functions.