Phomones A−C, Anti‐ Vibrio α ‐Pyrones From Phoma sp. NBUF235 Associated With an Ircinia Sponge From the Marine Mesophotic Zone

Three new α ‐pyrones, named as phomones A−C ( 1–3 ), together with three known analogs ( 4–6 ), were isolated from the fungus Phoma sp. NBUF235 associated with an Ircinia sp. sponge collected from the marine mesophotic zone. The discovery of these compounds was facilitated by bioassay‐guided isolation. Structural elucidation of these compounds was achieved through comprehensive spectroscopic analysis, and quantum chemistry calculations. Compounds 1 – 6 selectively inhibited the aquatic pathogenic bacteria Vibrio harveyi , V. parahaemolyticus , V. fluvialis , V. furnissii , V. mimicus , and V. cholerae (Non‐O1 strain), with MIC values ranging from 8 to 32 µg/mL. These findings enrich the chemical diversity of α ‐pyrones from sponge‐associated fungi in the marine mesophotic zone, providing promising molecules for the development of anti‐ Vibrio agents.