Ianthelliformisamines A−C, Antibacterial Bromotyrosine-Derived Metabolites from the Marine Sponge Suberea ianthelliformis

Abstract

A high-throughput screening campaign using a prefractionated natural product library and an in vitro Pseudomonas aeruginosa (PAO200 strain) assay identified two antibacterial fractions derived from the marine sponge Suberea ianthelliformis. Mass-directed isolation of the CH2Cl2/CH3OH extract from S. ianthelliformis resulted in the purification of three new bromotyrosine-derived metabolites, ianthelliformisamines A–C (1–3), together with the known natural products aplysamine 1 (4) and araplysillin I (5). The structures of 1–3 were determined following analysis of 1D and 2D NMR and MS spectroscopic data. This is the first report of chemistry from the marine sponge S. ianthelliformis. Ianthelliformisamine A (1) showed inhibitory activity against the Gram-negative bacterium P. aeruginosa with an IC50 value of 6.8 μM (MIC = 35 μM).