Sordarin Diterpene Glycosides with an Unusual 1,3-Dioxolan-4-one Ring from the Zoanthid-Derived Fungus Curvularia hawaiiensisTA26-15

Six new sordarin tetracyclic diterpene glycosides, moriniafungins B–G (1–6), and a new sordaricin tetracyclic diterpene, sordaricin B (8), together with two known analogues, moriniafungin (7) and sordaricin (9), were isolated from the zoanthid-derived fungus Curvularia hawaiiensisTA26-15. The structures of the new compounds were elucidated by comprehensive analyses of spectroscopic data, including 1D and 2D NMR and MS data. Compounds 1–6represent the first case of sordarins from marine-derived fungi possessing a sordarose with a spiro 1,3-dioxolan-4-one ring, which is rare in the nature. Compound 4showed antifungal activity against Candida albicansATCC10231 with an MIC value of 2.9 μM.