Botryotins A–H, Tetracyclic Diterpenoids Representing Three Carbon Skeletons from a Deep-Sea-Derived Botryotinia fuckeliana

Eight unprecedent diterpenoids, botryotins A–H (1–8), were obtained from Botryotinia fuckeliana. They represent three novel carbon skeletons with 6/6/5/5 (1), 6/6/5/6 (2–6), and 6/6/6/5 (7 and 8) tetracyclic scaffolds. Their structures were determined by detailed spectroscopic analysis and chemical derivatization as well as quantum chemical calculation of the ECD and OR data. Botryotin A (1) exhibited a moderate antiallergic effect (IC50 = 0.2...