Non-ATP competitive glycogen synthase kinase 3β (GSK-3β) inhibitors: Study of structural requirements for thiadiazolidinone derivatives

The 2,4-disubstituted thiadiazolidinones (TDZD) were described as the first non-ATP competitive GSK-3β inhibitors. New modifications in this heterocyclic ring are here reported to study the influence on the biological activity. The basic skeleton of 1,2,4-thiadiazole and also one of the carbonyl groups are kept, while different modifications are introduced in positions 3 and 5, respectively. The GSK-3β activity of the new thiadiazole derivatives here synthesized showed IC50 values for some of the compounds in the micromolar range. Additionally, ATP competition studies have been carried out, showing that as well as the first generation of TDZD, these new compounds act in a non-competitive manner. With this study, additional requirements for the biological activity of the TDZD family have been delineated.