Abstract:
Three unusual ajmaline-macroline type bisindole alkaloids, alsmaphylines A-C, together with their postulated biogenetic precursors, were isolated from the stem barks and leaves of Alstonia macrophylla via the building blocks-based molecular network (BBMN) strategy. Alsmaphyline A represents a rare ajmaline-macroline type bisindole alkaloid with an S-shape polycyclic ring system. Alsmaphylines B and C are two novel ajmaline-macroline type bisindole alkaloids with N-1-C-21\' linkages, and the former possesses an unconventional stacked conformation due to the presence of intramolecular noncovalent interactions. The chemical structures including absolute configurations of alsmaphylines A-C were established by comprehensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray crystallography. In addition, a plausible biosynthetic pathway of these bisindole alkaloids as well as their ability to promote the protein synthesis on HT22 cells were discussed.
摘要:
三种不寻常的ajmaline-macroline型双吲哚生物碱,AlsmphylinesA-C,连同他们假定的生物基因前体,通过基于结构单元的分子网络(BBMN)策略从大叶Alstonia的茎皮和叶片中分离。AlsmaphylineA代表一种稀有的ajmaline-macrolines型双吲哚生物碱,具有S形多环系统。AlsmaphlinesB和C是两种具有N-1-C-21键的新型ajmaline-macrolines型双吲哚生物碱,由于存在分子内非共价相互作用,前者具有非常规的堆叠构象。通过全面的光谱分析建立了化学结构,包括α-α-α的绝对构型,电子圆二色性(ECD)计算,和单晶X射线晶体学。此外,讨论了这些双吲哚生物碱的合理生物合成途径以及它们促进HT22细胞蛋白质合成的能力。