The total synthesis of five naturally occurring cyclic proline-enriched heptapeptides from the marine sponge Stylissa carteri was reported. The five cyclic heptapeptides were synthesized by applying a two-step solid-phase/solution synthesis strategy. The linear heptapeptides were assembled by standard Fmoc chemistry on 2-chlorotrityl chloride resin, cleaved off-resin with acetic acid/trifluoroethanol/dichloromethane to keep side-chain protecting groups intact, and subsequently cyclization was achieved by a solution method. The final products were purified by a preparative RP-HPLC system, and their structures were characterized by HR-QTOF-MS NMR. The spectral data of synthetic peptides were found to be identical to that reported for the natural products.

据报道，从海生海绵Stylissa carteri合成了五种天然富含环脯氨酸的七肽。通过应用两步固相/溶液合成策略合成了五个环状七肽。通过标准Fmoc化学将线性七肽组装在2-氯三苯甲基氯树脂上，用乙酸/三氟乙醇/二氯甲烷裂解树脂以保持侧链保护基完整，随后通过溶液法实现环化。通过制备型RP-HPLC系统纯化最终产物，并通过HR-QTOF-MS NMR表征其结构。发现合成肽的光谱数据与报道的天然产物的光谱数据相同。