Novel conjugates of tacrine with 1,2,4,-thiadiazole as highly effective cholinesterase inhibitors, blockers of NMDA receptors, and antioxidants.

Conjugates of tacrine with 1,2,4-thiadiazole derivatives were synthesized for the first time. Their esterase profile and effects on the key NMDA receptor-binding sites as well as antioxidant activity were investigated. The obtained compounds effectively inhibited cholinesterases (with a predominant effect on butyrylcholinesterase), simultaneously blocked two NMDA receptor-binding sites (allosteric and intrachannel sites, and exhibited a high radical-scavenging activity. Our study shows that the obtained compounds are promising to design drugs for the treatment of Alzheimer's disease and other multifactorial neurodegenerative diseases.