The possible reason may be that the addition of amino group induces fast intramolecular electron transfer and destroys intramolecular H-atom transfer process in peri-hydroxy perylenequinon ring.5.

• 可能是由于胺基的引入发生了分子内的电荷转移，破坏了竹红菌素母体的分子内质子转移过程。