A series of chiral thioureas (1 - 17) were synthesized from and tested for their anticholinesterase, tyrosinase, and urease enzyme inhibitor activities. Various phenylisothiocyanates were added to solution of ˪-cysteine in methanol: water (1 : 1 v / v) at room temperature and stirred for 24 h. The precipitated solid was recrystallized from n-butanol. Pure compounds were characterized by NMR (1 H and 13C), FTIR, and CHNS. |