The invention is directed to methods of treating ischemic stroke by adminis-tering a therapeutically effective amount of at least one compound of Formula I or Formula II to a subject in need thereof, wherein the compound has Formula I or Formula II: or a salt or ester of (I) or (II); wherein X is OH, C1-C6 alkoxyl, 18F, or 19F; Y and Z are independently selected from C1-C6 alkyl, C1-C6 alkoxyl, halogen, substituted or unsubstituted C1-C6 amine, 18F, 19F, or H; and n is 1, 2, or 3.