Work

Feature-Based Molecular Networking Discovery of Bromopyrrole Alkaloids from the Marine Sponge Agelas dispar

Year: 2022

Type: article

Abstract: Investigation of the marine sponge Agelas dispar MeOH fractions using feature-based molecular networking, dereplication, and isolation led to the discovery of new bromopyrrole-derived metabolites. An in-house library of bromopyrrole alkaloids previously isolated from A. dispar and Dictyonella sp. was utilized, along with the investigation of an MS/MS fragmentation of these compounds. Our strategy led to the isolation and identification of the disparamides A–C ( 1 – 3 ), with a novel carbon skeleton. Additionally, new dispyrins B–F ( 4 – 8 ) and nagelamides H2 and H3 ( 9 and 10 ) and known nagelamide H ( 11 ), citrinamine B ( 12 ), ageliferin ( 13 ), bromoageliferin ( 14 ), and dibromoageliferin ( 15 ) were also isolated and identified by analysis of spectroscopic data. Analysis of MS/MS fragmentation data and molecular networking analysis indicated the presence of hymenidin ( 16 ), oroidin ( 17 ), dispacamide ( 18 ), monobromodispacamide ( 19 ), keramadine ( 20 ), longamide B ( 21 ), methyl ester of longamide B ( 22 ), hanishin ( 23 ), methyl ester of 3-debromolongamide B ( 24 ), and 3-debromohanishin ( 25 ). Antibacterial activity of ageliferin ( 13 ), bromoageliferin ( 14 ), and dibromoageliferin ( 15 ) was evaluated against susceptible and multi-drug-resistant ESKAPE pathogenic bacteria Klabsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterococcus faecalis . Dibromoageliferin ( 15 ) displayed the most potent antimicrobial activity against all tested susceptible and MDR strains. Compounds 13 – 15 presented no significant hemolytic activity up to 100 μM.

Source: Journal of Natural Products

DOI: 10.1021/acs.jnatprod.2c00094