Positive attitude, shape, flexibility, addedvalue accessories or "just being different": How to attract a glycosidase

For nearly half a century, carbohydrate analogues with a basic nitrogen instead of oxygen in the sugar ring, so-called imino sugars (occasionally also addressed as "azasugars") have been known as powerful glycosidase inhibitors. Their profound interactions with the catalytic residues of glycoside hydrolases have made vital impact on our understanding of these enzymes and their finely tuned catalytic machinery. From these interactions, we have also learned and refined our concepts of exploiting glycosidases or means of their inhibition for many purposes. Thus, the old and familiar "pets" amongst the imino sugars as well as many new and novel derivatives have become useful tools, diagnostic compounds and therapeutic agents for glycochemistry and glycobiology.