Guanacastane-type diterpenoids with antifungal activity against Candida auris isolated from a Marine-derived fungus Coprinellus xanthothrix.

Five guanacastane-type diterpenoids, including a novel compound, guanacastepene V (1), and four known compounds (2-5) along with a novel diterpenoid moniliforminol C (6), were isolated from a marine-derived fungus, Coprinellus xanthothrix. The structures of the isolated compounds were elucidated using NMR spectroscopy and computational chemistry. In antifungal assays against Candida auris, an emerging fungal pathogen, compounds 1 and 2 exhibited inhibitory activity, with minimum inhibitory concentration values of 6.25 and 3.12 µg/mL, respectively. This antifungal effect was specific to C. auris, with minimal activity observed against C. albicans. Moreover, compound 4 exhibited synergistic effects with amphotericin B.