THERAPEUTIC AGENT FOR DIABETES

PROBLEM TO BE SOLVED: To provide a therapeutic agent for diabetes which comprises a 2-(N- cyanoimino)thiazolidin-4-one derivative, or its solvate or pharmaceutically permissive salt as an active component. SOLUTION: This 2-(N-cyanoimino)thiazolidin-4-one derivative represented by general formula (1) [wherein A ring is benzene ring, a condensed ring or a heterocycle all of which may be substituted with a linear of branched 1-4C alkyl group, an alkyl halide group or the like; R is a single bond, O, S, methine, a linear or branched 1-4C alkylene group which may be substituted with phenyl group, or the like; R2 and R3 are each H, a 1-4C alkyl group or the like; R4 is H or a 1-4C alkyl group; and the substitution site of methylene group at 5 position in thiazolidine shows both of E and Z] has excellent therapeutic action on diabetes and also has ameliorating action on hyperlipemia such as hypertriglyceridemia.