Related Experiment Video
Updated: Feb 24, 2026
Methods to Inhibit Bacterial Pyomelanin Production and Determine the Corresponding Increase in Sensitivity to Oxidative Stress
Published on: August 31, 2015
Tulongicin, an Antibacterial Tri-Indole Alkaloid from a Deep-Water Topsentia sp. Sponge
Hong-Bing Liu1, Gianluigi Lauro2, Robert D O'Connor1
1Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892-0820, United States.
Abstract:
Antibacterial-guided fractionation of an extract of a deep-water Topsentia sp. marine sponge led to the isolation of two new indole alkaloids, tulongicin A (1) and dihydrospongotine C (2), along with two known analogues, spongotine C (3) and dibromodeoxytopsentin (4). Their planar structures were determined by NMR spectroscopy. Their absolute configurations were determined through a combination of experimental and computational analyses. Tulongicin (1) is the first natural product to contain a di(6-Br-1H-indol-3-yl)methyl group linked to an imidazole core. The coexistence of tri-indole 1 and bis-indole alcohol 2 suggests a possible route to 1. All of the compounds showed strong antimicrobial activity against Staphylococcus aureus.
