Disclosed is a phosphate transport inhibiting compound represented by Structural Formula (I): ##STR00001## R1 and R2 are independently --H, an electron withdrawing group or a C.sub.1 C.sub.10 alkyl group. Y is a covalent bond, a substituted methylene group, an unsubstituted methylene group or --CR1R2P(O)(OH)--. R3 is a hydrocarbyl group optionally comprising one or more amine, ammonium, ether, thioether or phenylene linking groups, a substituted hydrocarbyl group optionally comprising one or more amine, ammonium, ether, thioether or phenylene linking groups, a heteroaryl group, a substituted heteroaryl group or a phenyl group substituted with one or more groups selected from --Cl, --Br, --F, --CN, --NO.sub.2, --OR.sup.a, --N(R.sup.a).sub.2, --COOR.sup.a, --CON(R.sup.a).sub.2, --COR.sup.a, --S(O)R.sup.a, --S(O).sub.2R.sup.a, --S(O).sub.2N(R.sup.a).sub.2, --NR.sup.aS(O).sub.2R.sup.a, --NR.sup.aCOR.sup.a, a halogenated lower alkyl group, an aryl group, a substituted aryl group, or a halogenated alkoxy group. Each R.sup.a is independently --H, lower alkyl, substituted lower alkyl, aryl or substituted aryl. Each Rb is independently --H, a lower alkyl group, or a phosphate protecting group.