Chromone Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus KUFA0220 and Their Antibacterial Activity.

A previously unreported chromene derivative, 1-hydroxy-12-methoxycitromycin (), and four previously undescribed chromone derivatives, including pyanochromone (), spirofuranochromone (), 7-hydroxy-6-methoxy-4-oxo-3-[(1)-3-oxobut-1-en-1-yl]-4-chromene-5-carboxylic acid (), a pyranochromone dimer () were isolated, together with thirteen known compounds: β-sitostenone, ergosterol 5,8-endoperoxide, citromycin (), 12-methoxycitromycin (), myxotrichin D (), 12-methoxycitromycetin (), anhydrofulvic acid (), myxotrichin C (), penialidin D (), penialidin F (), SPF-3059-30 (), GKK1032B () and secalonic acid A (), from cultures of the marine sponge- associated fungus KUFA0220. Compounds ⁻, , , , ⁻, were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only exhibited an in vitro growth inhibition of all Gram-positive bacteria whereas showed growth inhibition of methicillin-resistant (MRSA). None of the compounds were active against Gram-negative bacteria tested.