Sulfonamide derivatives exhibit a wide biological activity and can function as potential medical molecules in the development of a drug. Studies have reported that the compounds have an effect on many enzymes. In this study, the derivatives of amine sulfonamide (1i-11i) were prepared with reduced imine compounds (1-11) with NaBH₄ in methanol. The synthesized compounds were fully characterized by spectral data and analytical. The effect of the synthesized derivatives on acetylcholinesterase (AChE), glutathione S-transferase (GST) and α-glycosidase (α-GLY) enzymes were determined. For the AChE and α-GLY, the most powerful inhibition was observed on 10 and 10i series with K _I value in the range 2.26 ± 0.45–3.57 ± 0.97 and 95.73 ± 13.67–102.45 ± 11.72 µM, respectively. K _I values of the series for GST were found in the range of 22.76 ± 1.23–49.29 ± 4.49. Finally, the compounds have a stronger inhibitor in lower concentrations by the attachment of functional electronegative groups such as two halogens (-Br and -CI), -OH to the benzene ring and -SO₂NH₂. The crystal structures of AChE, α-GLY, and GST in complex with selected derivatives 4 and 10 show the importance of the functional moieties in the binding modes within the receptors. Communicated by Ramaswamy H. Sarma

Carbonic anhydrase (CA) has a key role in respiration, carbon dioxide and bicarbonate transport. Acetylcholinesterase (AChE) is a serine hydrolase and mostly abundant at neuromuscular junctions and cholinergic brain synapses. Inhibitors of these enzymes could aid in illuminating the role in disease processes. In this study, we separately purified CA I and CA II from human erythrocytes. The purity of the enzymes was showed by SDS-PAGE analysis. We also investigated the inhibition of seven chalcones toward hCA I, hCA II, and AChE. The chalcones were effective inhibitors of the cytosolic CA isoforms (hCA I and hCA II) and AChE with K_i values in the range of 1.83–7.05 μM for hCA I, 0.59–5.50 μM for hCA II, and 0.61–86.11 μM for AChE. All compounds were showed competitive inhibition aganist both enzymes. These compounds can be a potent inhibitor of AChE enzyme and both cytosolic CA isoenzymes which are commonly used in the pharmaceutical and medical industries.