Thiazolidines and oxazolidines substituted by a pyridine ring and their use as hypoglycemic agents

The present invention provides novel pyridine type thiazolidines and their salts, expressed by formula (I) (wherein X is S or O; X is S, O or NH; Y is CR R , R is a hydrogen atom, a C1-C7 alkyl group or a C3-C7 cycloalkyl group, and R is a hydrogen atom, a C1-C7 alkyl group or a C3-C7 cycloalkyl group or forms a bond together with R ), or SO2; Z is a C1-C10 alkyl group, a C2-C10 alkenyl group, a C2-C10 alkynyl group, a C3-C7 cycloalkyl group, a C3-C7 cycloalkenyl group (each of said alkyl, alkenyl, alkynyl, cycloalkyl and cycloalkenyl groups may be substituted with at most 3 of hydroxyl, oxo, C1-C7 alkyl and C1-C7 alkoxy groups), a phenyl group, a biphenyl group, an alpha -naphthyl group, a beta -napthyl group, a benzyl group or a heterocyclic group. The compounds have a hypoglycemic effect.