Synthesis and evaluation of acetylcholineesterase inhibitory potential and antioxidant activity of benzothiazine derivatives

The aim of the present study was to synthesize and characterize benzothiazine derivatives prepared by using 2-aminothiophenol and saccharine and in vitro screen their enzyme inhibition and antioxidant potential. Nine different derivatives were prepared and their structures were confirmed by spectral studies (EIMS, ^1 H and ^13 C NMR). Enzyme inhibition potential of the synthesized compounds was evaluated by Ellman’s method, while antioxidant activity was determined by DPPH and FRAP assays. All the derivatives showed remarkable activity against acetylcholine esterase with IC50 values in the range of 35.9–122.0 μM. All other derivatives, except compound 4a, were inactive towards DPPH radical. The results of the FRAP assay showed significant reducing potential of compounds 1, 2, 2a, and 4a.