Anthraquinone Derivatives and Other Aromatic Compounds from Marine Fungus KMM 4696 and Their Effects against .

New anthraquinone derivatives acruciquinones A-C (-), together with ten known metabolites, were isolated from the obligate marine fungus KMM 4696. Acruciquinone C is the first member of anthraquinone derivatives with a 6/6/5 backbone. The structures of isolated compounds were established based on NMR and MS data. The absolute stereoconfigurations of new acruciquinones A-C were determined using ECD and quantum chemical calculations (TDDFT approach). A plausible biosynthetic pathway of the novel acruciquinone C was proposed. Compounds - and - showed a significant antimicrobial effects against growth, and acruciquinone A (), dendryol B (), coniothyrinone B (), and ω-hydroxypachybasin () reduced the activity of a key staphylococcal enzyme, sortase A. Moreover, the compounds, excluding , inhibited urease activity. We studied the effects of anthraquinones , , , and and coniothyrinone D () in an in vitro model of skin infection when HaCaT keratinocytes were cocultivated with . Anthraquinones significantly reduce the negative impact of on the viability, migration, and proliferation of infected HaCaT keratinocytes, and acruciquinone A () revealed the most pronounced effect.