Inhibitors of bacterial glutaminyl cyclases for use in the treatment of periodontal and related diseases

A compound according to the following Formula I,

• its individual enantiomers, its individual diastereoisomers, its hydrates, its solvates, its crystal forms, its individual tautomers or a pharmaceutically acceptable salt thereof, wherein:
• A is selected from the group consisting of optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted cycloalkyl and optionally substituted alkenyl;
• R1 is independently selected from the group consisting of H and optionally substituted alkyl;
• L is
• Ra and Rb are the same or different from each other and are independently selected from the group consisting of H, halo, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroalkyl and optionally substituted heteroaryl, and wherein Ra and Rb can optionally be joined together to form a carbocyclic or a heterocyclic ring.