Stylissatin A is a proline-rich cyclic heptapeptide isolated from the Papua New Guinean marine sponge Stylissa massa. The first synthesis of stylissatin A was achieved by a combination of solid-phase and solution-phase peptide synthesis. The natural and synthetic samples of stylissatin A showed comparable inhibitory effects on nitric oxide production with negligible cytotoxicity in lipopolysaccharide (LPS)-stimulated murine macrophage RAW264.7 cells (EC50 = 73 µM for synthetic sample). Furthermore, while the d-allo-Ile5 epimer was less potent, a tert-butyl ether analog of stylissatin A was approximately six times more potent than the natural product (EC50 = 12 µM).
海洋海绵Stylissa massa中分离得到一种富含脯
氨酸的七肽环化合物Stylissatin A,它来自巴布亚新几内亚。Stylissatin A的首次合成是通过固相和液相肽合成相结合实现的。天然和合成样品的Stylissatin A均显示出相当的抑制
一氧化氮产生的效果,对脂
多糖(LPS)刺激的小鼠巨噬细胞RAW264.7细胞的细胞毒性可忽略不计(合成样品的
EC50 = 73 µM)。此外,尽管d-allo-Ile5的差向异构体效力较低,但Stylissatin A的叔丁基
醚类似物的效力大约是
天然产物的六倍(
EC50 = 12 µM)。