Synthesis, characterisation, biological evaluation and in silico studies of sulphonamide Schiff bases

Abstract

Sulphonamides are biologically important compounds with low toxicity, many bioactivities and cost-effectiveness. Eight sulphonamide derivatives were synthesised and characterised by FT-IR, ¹³C NMR, ¹H NMR, LC-MS and elemental analysis. Their inhibitory effect on AChE, and carbonic anhydrase I and II enzyme activities was investigated. Their antioxidant activity was determined using different bioanalytical assays such as radical scavenging tests with ABTS^•+, and DPPH^•+ as well as metal-reducing abilities with CUPRAC, and FRAP assays. All compounds showed satisfactory enzyme inhibitory potency in nanomolar concentrations against AChE and CA isoforms with K_I values ranging from 10.14 ± 0.03 to 100.58 ± 1.90 nM. Amine group containing derivatives showed high metal reduction activity and about 70% ABTS radical scavenging activity. Due to their antioxidant activity and AChE inhibition, these novel compounds may be considered as leads for investigations in neurodegenerative diseases.

Keywords:

• Acetylcholinesterase
• carbonic anhydrase
• synthesis
• sulphonamide
• molecular docking

Acknowledgements

The authors thank Harran University, Scientific Research Council (HÜBAK, Projects number: 18168) for financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was in part also funded by the Researchers Supporting Project No. (RSP-2019/1) King Saud University, Riyadh, Saudi Arabia.