Chlovalicin B, a Chlorinated Sesquiterpene Isolated from the Marine Mushroom .

As part of our search for bioactive metabolites from understudied marine microorganisms, the new chlorinated metabolite chlovalicin B () was isolated from liquid cultures of the marine basidiomycete , which was collected and isolated from driftwood found at Vannøya, Norway. The structure of the novel compound was elucidated by spectroscopic methods including 1D and 2D NMR and analysis of HRMS data, revealing that shares its molecular scaffold with a previously isolated compound, chlovalicin. This represents the first compound isolated from the genus, and the first reported fumagillin/ovalicin-like compound isolated from Basidiomycota. Compound was evaluated for antibacterial activities against a panel of five bacteria, its ability to inhibit bacterial biofilm formation, for antifungal activity against , and for cytotoxic activities against malignant and non-malignant human cell lines. Compound displayed weak cytotoxic activity against the human melanoma cell line A2058 (~50% survival at 50 µM). No activity was detected against biofilm formation or at 50 µM, or against bacterial growth at 100 µM nor against the production of cytokines by the human acute monocytic leukemia cell line THP-1 at 50 µM.