Fourteen N, N′-diaryl unsymmetrically substituted thioureas were synthesised and their cytotoxic (in vitro), phytotoxic (in vitro), acetylcholinesterase and butrylcholinesterase activities were determined. Thiourea 16 exhibited high, and 1 and 3 showed significant phytotoxic activity. Thioureas 1, 3, 4, 6 and 10 showed significant activity and 2, 6 and 7 indicated moderate cytotoxic activities. Compound 12 exhibited butrylcholinesterase ...