The invention provides compounds of formula (I), ##STR00001## prodrugs
and stereoisomers thereof, and the pharmaceutically acceptable salts of
the compounds, prodrugs, and stereoisomers, wherein R.sup.1, R.sup.2,
R.sup.3, HET, n, Q, X, Y, and Z are as described herein; compositions
thereof; and uses thereof in treating diabetic complications including
diabetic neuropathy, diabetic nephropathy, diabetic microangiopathy, and
the like.