The present invention provides 4-isopropylphenyl glucitol compounds which haveno tendency to accumulate inthe body and which inhibit SGLT1 activity to suppress postprandialhyperglycemia (or impaired glucose tolerance) through suppressionof glucose absorption in the small intestine, whereby the compounds, forexample, can suppress the onset of diabetes andmetabolic syndrome or can treat these diseases. A 4-isopropylphenyl glucitolcompound represented by the following formula (I)or a pharmaceutically acceptable salt thereof: [Chem. 1] wherein R1 representsa hydrogen atom, etc., R2 represents a methylgroup, etc., R3 represents a C1-4 alkyl group substituted with an aminogroup(s), etc., and R4 represents a hydrogen atom, etc.
