In connection with our studies on hydantoin derivatives, a conventional regioselective chemical transformation of 5-methylene hydantoins 4a-c to 5-aminomethyl-substituted hydantoins 5-10 or to 5-amino-5-methyl-disubstituted hydantoins 11-14 is described. Synthesis of bivalent twin-drug type hydantoin derivatives 19-24 and the binding property of a bivalent symmetrical hydantoin derivative 24b to sulfated glycosaminoglycans are also described.