Equisetin, an N-methylserine-derived acyl tetramic acid isolated from the terrestrial fungus Fusarium equiseti NRRL 5537, functions as a Quorum-sensing inhibitor (QSI) that specifically attenuates QS-regulated virulence phenotypes in P. aeruginosa, presenting a potent lead for treating P. aeruginosa infections without hindering bacterial growth. This tetramate-containing natural product possesses antibiotic and cytotoxic properties, effectively inhibiting the growth of Gram-positive bacteria and HIV-1 integrase activity, yet it does not impact Gram-negative bacteria.
