Provided herein are compositions and related methods useful for prevention or mitigation of ionizing radiation-induced esophagitis. The compositions comprise compounds comprising a nitroxide-containing group attached to a mitochondria-targeting group. The compounds can be cross-linked into dimers without loss of activity. The method comprises delivering a compound, as described herein, to a patient in an amount and dosage regimen effective to prevent or mitigate esophageal damage caused by radiation.