Provided herein are Aminopurine Compounds having the following structure:wherein R1, R2 and R3 are as defined herein, compositions comprising an effective amount of an Aminopurine Compound and methods for treating or preventing scleroderma, keloids, UV injury, or sunburn, and methods for improving or preventing scar formation.本發明提供具有以下結構之胺基嘌呤化合物:其中R1、R2及R3係如本文所定義,及包含有效量胺基嘌呤化合物之組合物,及治療或預防硬皮病、瘢痕瘤、UV損傷或曬傷之方法,及改善或預防瘢痕形成之方法。