Sorbicitrinols A and B, Two Sorbicillinoids with Unprecedented Skeletons Uncovered from Sponge-Derived Fungus Penicillium sp. S4I4-3 by a Molecular Networking Strategy

Sorbicitrinol A (1) and its biosynthetic precursor sorbicitrinol B (2), two novel sorbicillinoids with unprecedented skeletons, were isolated from the sponge-derived fungus Penicillium 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 1 was the first example of a sorbicillinoid featuring the unique cage-like 2,5-dioxa-pentacyclo[10.4.03,11.04,8.04,15]tetradecane scaffold. Plausible biogenetic pathways were proposed, and their antitumor and antifungal activities were also evaluated.