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Structure Reassignment of Echinosulfone A and the Echinosulfonic Acids A-D Supported by Single-Crystal X-ray
Samuele Sala1, Gareth L Nealon1, Alexandre N Sobolev1
1School of Molecular Sciences , The University of Western Australia , Crawley , WA 6009 , Australia.
Abstract:
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.
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