2-(N-CYANIMINO)THIAZOLIDIN-4-ON DERIVATE

This invention provides novel 2-(N-cyanoimino)thiazolidin-4-one derivatives represented by formula I or a pharmaceutically acceptable salt or solvate thereof: wherein ring A represents a benzene ring, a condensed ring or a heterocyclic ring, each of which may be substituted by one or more substituents selected from a straight or branched C1 - C4 alkyl group, a haloalkyl group, a halogen atom or -OR , R represents a single bond, an oxygen atom, a sulfur atom, a methyne group, a straight or branched C1 - C4 alkylene or alkenylene group optionally substituted by a phenyl group, R -X X-R , X-R -X R -X-R , -C(=O)-NR - or -NR -C(=O)-, R and R are the same or different and each represents a hydrogen atom, a C1 - C4 alkyl group, -OR or a halogen atom, R represents a hydrogen atom or a C1 - C4 alkyl group, R represents a hydrogen atom or a C1 - C4 alkyl group, R represents a straight or branched C1 - C4 alkylene or alkenylene group, R represents a hydrogen atom or a C1 - C4 alkyl group, R represents a hydrogen atom, a C1 - C4 alkyl group or an aralkyl group, X represents an oxygen atom or a sulfur atom. They have excellent activities of lowering triglyceride and cholesterol levels, and are useful for preventing from and/or treating hyperlipidemia and related complications.