A new antibacterial imidazole from the marine sponge Iricinia fusca

A new imidazole alkaloid (1) along with two known compounds, variabilin (2) and iricinialactam A (3) have been isolated from the Arabian marine sponge Ircinia fusca. The structure of the new compound was established as 4-((1, 2-dihydroxy-5-(methyl (1-methyl-1H-imidazol-4-yl) amino) pentan-3-yl) oxy)-3, 5-dimethoxy-1-methylpyrrolidin-2-one (1) by 1D and 2D NMR, and high-resolution electrospray ionization mass spectrometry (HRESIMS). Compound 1 exhibited selective growth inhibitory activity against gram-positive bacteria S. aureus at 100 µg/mL