Trachycladindoles H-M: Molecular Networking Guided Exploration of a Library of Southern Australian Marine Sponges

A global natural product social (GNPS) molecular network guided search of a library of 960 southern Australian marine sponge extracts successfully detected a deep-water Great Australian Bight sponge, Geodia sp. (CMB-01063), as a new source of a rare class of indolo-imidazole alkaloids previously believed to be unique to a single specimen of Trachycladus laevispirulifer (CMB-03397). Chemical analysis of CMB-01063 detected the known trachycladindoles A-G (1-7), and led to the isolation, characterisation, and structure elucidation of the new trachycladindoles H-M (8-13). Structures for 8-13 were assigned on the basis of detailed spectroscopic analysis, with comparison to authentic standards of 1-7.