AbstractAmifostine has been the only small molecule radio-protector approved by FDA for decades; however, the serious adverse effects limit its clinical use. To address the toxicity issues and maintain the good potency, a series of modified small polycysteine peptides had been prepared. Among them, compound 5 exhibited the highest radio-protective efficacy, the same as amifostine, but much better safety profile. To confirm the correlation between the radiation-protective efficacy and the DNA binding capability, each of the enantiomers of the polycysteine peptides had been prepared. As a result, the l-configuration compounds had obviously higher efficacy than the corresponding d-configuration enantiomers; among them, compound 5 showed the highest DNA binding capability and radiation-protective efficacy. To our knowledge, this is the first study that has proved their correlations using direct comparison. Further exploration of the mechanism revealed that the ionizing radiation (IR) triggered ferroptosis inhibition by compound 5 could be one of the pathways for the protection effect, which was different from amifostine. In summary, the preliminary result showed that compound 5, a polycysteine as a new type of radio-protector, had been developed with good efficacy and safety profile. Further study of the compound for potential use is ongoing.
摘要:Amifostine是美国食品药品监督管理局(FDA)批准使用数十年的唯一一种小分子放射防护剂,然而,严重的不良反应限制了其临床应用。为了解决毒性问题并保持良好的效力,已制备了一系列改性的小多硫氨基酸肽。其中,化合物5表现出与Amifostine相同的最高放射防护效力,但安全性更好。为了确认辐射保护效力与DNA结合能力之间的相关性,已制备了每个多硫氨基酸肽的对映体。结果表明,l-构型化合物的效力明显高于相应的d-构型对映体;其中,化合物5显示出最高的DNA结合能力和放射防护效力。据我们所知,这是第一项通过直接比较证明它们之间相关性的研究。进一步探索机制揭示,化合物5引发的电离辐射(IR)诱导的铁死亡抑制可能是保护效果的途径之一,与Amifostine不同。总之,初步结果显示,作为一种新型放射防护剂的多硫氨基酸化合物5,具有良好的效力和安全性。对该化合物进行进一步研究以探讨其潜在用途仍在进行中。