Benzothiazole derivatives as novel inhibitors of human 11β-hydroxysteroid dehydrogenase type 1

Selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have considerable potential as treatments for metabolic diseases, such as diabetes mellitus type 2 or obesity. Here, we report the discovery and synthesis of a series of novel benzothiazole derivatives and their inhibitory activities against 11β-HSD1 from human hepatic microsomes measured using a radioimmunoassay (RIA) method. The benzothiazole derivatives 1 and 2 showed greater than 80% inhibition for 11β-HSD1 at 10 μM and exhibited IC50 values in the low micromolar range. The preliminary SAR study suggested the introduction of a chlorine substituent at the 4 position of the benzothiazole ring greatly enhanced the inhibitory activities. Docking studies with the benzothiazole derivative 1 into the crystal structure of human 11β-HSD1 revealed how the molecule may interact with the enzyme and cofactor.