Synthesis and Glycosidase Inhibitory Activity of Azasugars

There is growing interest amongst scientific community in a heterogeneous group of hydrophilic plant alkaloids like polyhydroxylated monocyclic piperidine, pyrrolidine and bicyclic indolizidine, pyrrolizidine, quinolizidine and nortropane owing to their potential biological activities. These alkaloids have been given various generic names e.g. azasugars, iminosugars, polyhydroxy alkaloids, aminosugars etc. So, azasugars are polyhydroxylated alkaloids in which the endocyclic oxygen atom of the sugar ring is replaced with the basic nitrogen. Mere this atomic substitution confers these compounds with the ability to mimic sugars and inhibit various carbohydrate processing enzymes; most significantly the glycosidases (glycoside hydrolases) which are intimately involved in a huge array of biological functions. The present book described the natural occurrence of piperidine homoazasugars, pyrrolidine homoazasugars, bicyclic diazasugars and 1-azasugars. The synthetic aspects of these azasugars using a number of methodologies including chemo-enzymatic methods have discussed. The structural basis for the specificity of glycosidase inhibition and biological application is also described.