The present invention addresses the problem of: developing a compound that has few side effects on the body and exhibits an uncoupling effect and/or an immunosuppressive effect； and providing a weight-gain inhibitor or immunosuppressant in which said compound is an active ingredient. A compound that can be represented by general formula (I), or a salt thereof, is provided. (I) (In the formula, R1 represents a hydrogen atom (H) or a C5, C10, C15, or C20 prenyl group； R2 represents a C1-10 straight-chain or branched alkyl group or a C5, C10, C15, or C20 prenyl group； and R3 and R4 each independently represent a C5, C10, C15, or C20 prenyl group (albeit not a C5 prenyl group if R1 represents a hydrogen atom and R2 represents a methyl group) or an isopentyl group.)
