Many compounds are known that can act to inhibit the action of a glycoside hydrolase.  Nitrogen-containing, sugar-shaped heterocycles have been found in nature, including deoxynojirimycin, swainsonine, australine and castanospermine.  From these natural templates many other inhibitors have been developed, including isofagomine and deoxygalactonojirimycin, and various unsaturated compounds such as PUGNAc.  Inhibitors that are in clinical use include the anti-diabetic drugs acarbose and miglitol, and the antiviral drugs oseltamivir and zanamivir.  Some proteins have been found to act as glycoside hydrolase inhibitors.