Suntamide A (1), a new cyclic peptide, was isolated from Cicadidae Periostracum. The gross structure of 1 was elucidated by detailed analysis of HRMS and 1D/2D NMR spectra, and the absolute configuration was established by C3 Marfey’s method. We extended our study to examine biological activity of 1, and found that 1 protected SH-SY5Y cells against rotenone-induced neurotoxicity. This effect of 1 seemed to be attributed to antioxidant induction and protection of mitochondria from rotenone-caused injury. Along with augmentation of the antioxidant system by 1, there was an evident activation of Nrf2, a transcription factor involved in the activation of the antioxidant system. These results indicate that 1 rescued the cells from rotenone-mediated neurotoxicity by enhancing antioxidant capacity via induction of Nrf2, suggesting that the compound could be used as a therapeutic intervention in neurodegenerative diseases such as Parkinson’s disease.

Suntamide A ( 1 ) 是一种新的环状肽，是从蝉科植物膜中分离出来的。通过 HRMS 和 1D/2D NMR 光谱的详细分析阐明了1的总体结构，并通过 C3 Marfey 方法建立了绝对构型。我们扩展了我们的研究以检查1 的生物活性，并发现1保护 SH-SY5Y 细胞免受鱼藤酮诱导的神经毒性。1 的这种作用似乎归因于抗氧化诱导和线粒体保护免受鱼藤酮引起的损伤。随着抗氧化系统增加1，Nrf2 明显激活，Nrf2 是一种参与抗氧化系统激活的转录因子。这些结果表明1通过诱导 Nrf2 增强抗氧化能力使细胞免于鱼藤酮介导的神经毒性，这表明该化合物可用作神经退行性疾病（如帕金森病）的治疗干预。