Acetylcholinesterase and Butyrylcholinesterase Inhibitory Activities of 5-Arylidene-N, N-Diethylthiobarbiturates

5-Arylidene-N,N-diethylthiobarbiturates 1-25 were evaluated for their potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes and displayed varying degree of inhibition. Based on the IC50 values, compound 6 (IC50 = 92.51 and#177; 0.01 and#181;M) was the only active compound against acetylcholinesterase, however this compound was also weakly active against butyrylcholinesterase with an IC50 value 124.76 and#177; 0.02 and#181;M. Six compounds 1, 6, 7, 16, 17, and 18 showed weak inhibition against BChE, among them compound 18 (IC50 = 82.25 and#177; 0.07and#181;M) showed good inhibition against BChE. Nevertheless, compounds 1, 7, 16, 17, and 18 were selectively active against BChE enzyme.