Two previously reported bis-indole alkaloids, echinosulfone A and echinosulfonic acid B, have been isolated for the first time from a Western Australian marine sponge, Crella sp. (order: Poecilosclerida, family: Crellidae). Single-crystal X-ray diffraction of a decomposition product of echinosulfone A prompted our investigation and subsequent structure reassignment of the echinosulfonic acid natural product family, which we report here. The reassignments are supported by analysis of 1D and 2D NMR data, MS fragmentation, and DFT calculations of 13C NMR shifts.

中文翻译：

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单晶X射线衍射和密度泛函理论分析支持的Echinosulfone A和Echinosulfonics AD的结构重新分配。

先前从西澳大利亚海洋海绵Crella sp。中首次分离出了两个先前报道的双吲哚生物碱，棘皮砜A和棘皮磺酸B。（顺序：Poecilosclerida，家庭：Crellidae）。棘皮砜A分解产物的单晶X射线衍射促使我们进行了研究，并随后对棘皮磺酸天然产物家族的结构进行了重新分配，我们在此进行了报道。通过1D和2D NMR数据分析，MS片段化和13C NMR位移的DFT计算，可以支持重新分配。