Abstract: The present invention relates to novel compounds representated by formula (I), where R, R1, R2, R3, X, Y, m, n are as defined. The present invention relates to compounds of the general formula I their derivatives, their analogs, their tautomeric forms, their stereoisomers, their diastereomers, their bioisosteres, their polymorphs, their pharmaceutically acceptable salts and pharmaceutically acceptable compositions containing them which are predominantly dipeptidyl peptidase IV inhibitors. The present invention also relates to the processes for the preparation of novel compounds of formula (I) and their use in treating type II diabetes and diabetic complications thereof and also for treating dislipidemia, hypercholesterolemia, obesity and hyperglycemia.