Ocauxarthrol A from Auxarthron umbrinum SCSIO 40432 and configurational reassignment of chrysoqueen and auxarthrols

Abstract A new tetrahydroanthraquinone (TAQ), ocauxarthrol A (1), as well as six known analogs, chrysoqueen (2), auxarthrols B (3), E (4), H (5), A (6), and paradictyoarthrin A (7), were isolated from the plateau soil-derived fungus Auxarthron umbrinum SCSIO 40432. X-ray crystallographic analyses were utilized to confirm the presence of a carbonate group in ocauxarthrol A (1) and to reassign the stereochemistry for 2–5. None of the compounds exhibited obvious antimicrobial or enzyme inhibitory activity.