Polyhydroxy alkaloids are the compounds in which the oxygen atom of carbohydrate ring is replaced by a nitrogen atom and they are now believed to be widespread in plants and microorganisms. Modern pharmacological studies and clinical practices have confirmed that these compounds can selectively inhibit glycosidases activities. Glycosidases play an important part in many process such as intestinal digestion, post-translation of glycoproteins, the lysosomal catabolism of glycoconjugates, so polyhydroxy alkaloids have intensively therapeutic potential application in diabetes, anticancer, antivirus and the lysosomal diseases treatment. These compounds structures, sources, purification, biological activities, structure-activity relationships and prospects for therapeutic application are summarized.

Key words: sugar-mimic, glycosidase inhibitor, biological activity, polyhydroxy alkaloid