Novel glutaminyl cyclase inhibitors

The invention relates to a compound of formula (I): A-B-D-E (I) or a pharmaceutically acceptable salt, solvate or polymorph thereof, including all tautomers and stereoisomers thereof, wherein: A is selected from monocyclic and bicyclic heteroaryl, which may independently substituted by alkyl or amino; B is selected from alkylene, heteroalkylene and -(CH2)[0-1]-(p-phenylene)-(CH2)[0-1]-, which may independently be substituted by alkyl; D is selected from aryl-amino and heteroaryl-amino; and E is selected from aryl and heteroaryl. The compounds of formula (I) are inhibitors of glutaminyl cyclase (QC, EC 2.3.2.5). QC catalyzes the intramolecular cyclization of N-terminal glutamine residues into pyroglutamic acid (5-oxo-prolyl, pGlu*) under liberation of ammonia and the intramolecular cyclization of N- terminal glutamate residues into pyroglutamic acid under liberation of water.