(penicillanthone, 1) and three new diphenylether derivatives (penicillidic acids A–C, 2–4) together with 14 known compounds (5–18) were isolated from the soil-derived fungus Penicillium aculeatum PSU-RSPG105. The structures were elucidated by spectroscopic analyses. The absolute configuration of compound 1 was determined using the Snatzke's method whereas those of compounds 2–4 was established by comparison