Abstract: A compound of formula (I) or a tautomeric form, regioisomer, stereoisomer, solvate, N-oxide or pharmaceutically acceptable salts thereof; wherein ‘a’—is selected from the group consisting of substituted or unsubstituted heterocycloalkyl ring and substituted or unsubstituted carbohydrate moiety y is a member selected from —O—, —CO—, —S02-, aminoalkyl or formula (II) wherein, Rw is hydrogen, substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl; x is a member selected from -0-, —S—, —SO—, —S02-, CONR10, NR10CO and —NRd—, or x and y together represent a chemical bond; Z is selected from —CH—, —N—. t is an integer selected from O to 4; with the provisos that when ‘a’ is substituted or unsubstituted heterocycloalkyl ring then ‘t’ is not O and when y=—CO—, x is not NRd.