Synthesis, Antioxidant, and Antiacetylcholinesterase Activities of Sulfonamide Derivatives of Dopamine‐ R elated Compounds

A series of sulfonamides were synthesized from dopamine derivatives. The reactions of amines with methanesulfonyl chloride followed by O ‐demethylation with BBr 3 afforded phenolic sulfonamides. The antioxidant activities of the synthesized phenolic sulfonamides were investigated by thiocyanate method, 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS •+ ), 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH • ), N , N ‐dimethyl‐ p ‐phenylenediamine (DMPD •+ ), and superoxide anion (O 2 •− ) radical scavenging, reducing power, and ferrous ion (Fe 2+ ) chelating assays. Sulfonamides 13 – 16 showed around 75–85% inhibition on linoleic acid peroxidation. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α‐tocopherol, and trolox indicated an inhibition of 90.0%, 85.73%, 73.33%, and 85.73% on peroxidation, respectively, in the same system at the same concentration (10 µg/mL). Also, the inhibition effects of the synthesized compounds on acetylcholinesterase (AChE) activity were evaluated. AChE was effectively inhibited by sulfanomides 13 – 16 , with K i values in the range of 33.04 ± 4.3 to 131.68 ± 8.8 nM.