Recently, the serine/threonine kinase glycogen synthase kinase-3 (GSK-3) emerged as a regulator of pancreatic β cell growth and survival. On the basis of the previous observation that GSK-3 inhibitors like 1-azakenpaullone promote β cell protection and replication, paullone derivatives were synthesized including 1-aza-, 2-aza-, and 12-oxapaullone scaffolds. In enzymatic assays distinct 1-azapaullones were found to exhibit selective GSK ...