SorbicitrinolsA and B, Two Sorbicillinoids with UnprecedentedSkeletons Uncovered from Sponge-Derived Fungus <i>Penicillium</i> sp. S4I4‑3 by a Molecular Networking Strategy

Sorbicitrinol A (<b>1</b>) and its biosynthetic precursor sorbicitrinol B (<b>2</b>), two novel sorbicillinoids with unprecedented skeletons, were isolated from the sponge-derived fungus <i>Penicillium</i> sp. by molecular networking. Their structures were identified by spectroscopic analyses and quantum chemistry. Both of them exhibited an innovative fusion pattern of sorbicillinol and a citrinin derivative. Compound <b>1</b> was the first example of a sorbicillinoid featuring the unique cage-like 2,5-dioxa-pentacyclo[10.4.0^3,11.0^4,8.0^4,15]tetradecane scaffold. Plausible biogenetic pathways were proposed, and their antitumor and antifungal activities were also evaluated.