New Sulfurated Butyrolactones from the Fungus Penicillium janthinellum

Deep‐sea derived fungi are considered as significant resources to discovery structurally diverse and biologically active natural compounds. In this study, four new sulfurated butyrolactones, penijanthiones A–D (1–4), together with four known analogues (5‐8), were isolated from a Mariana Trench‐derived fungus Penicilliumjanthinellum SH0301. Compounds 1–4 were the undescribed examples for natural butyrolactones coupling with a mercaptolactate moiety. Their structures including the absolute configurations of these new compounds were elucidated by comprehensive spectroscopic data, and calculated electronic circular dichroism (ECD). The plausible biosynthetic pathway of sulfur‐incorporation of 1–4 was proposed. All of these isolated compounds were evaluated their cytotoxic, antimicrobial and antiviral activities.