Inositol derivatives are described that are represented by the structural formula I wherein X is a radical of scyllo-inositol wherein one or more of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently alkyl, alkenyl, alkynyl, alkylene, alkenylene, alkoxy, alkenyloxy, cycloalkyl, cycloalkenyl, cycloalkoxy, aryl, aryloxy, arylalkoxy, aroyl, heteroaryl, heterocyclic, acyl, acyloxy, sulfoxide, sulfate, sulfonyl, sulfenyl, sulfonate, sulfinyl, amino, imino, azido, thiol, thioalkyl, thioalkoxy, thioaryl, nitro, cyano, halo, seleno, silyl, silyloxy, silylthio, carboxyl, carbonyl, carbamoyl, or carboxamide and the other of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, or R.sup.6 are hydroxyl, or pharmaceutically acceptable salts thereof. The compounds, compositions comprising same and methods using same are described for use in the prevention and/or treatment of diseases characterized by abnormal protein folding or aggregation or amyloid formation, desposition, accumulation or persistence.