“…Prior to the isolation of massarinolin A, only expansolides A and B (5 a, 5 b), a pair of C4 epimers, share the same tetracyclic ring system. [2] Later on, closely related molecules such as purpurolides B, D, and E (2, 3, and 4), [3] expansolides C and D (6 a, 6 b), [4] and decipienolides A and B (7 a, 7 b) [5] were isolated and characterized. Purpurolides C and F (8, 9) and eutypellacytosporins A-D [6] (10 a, 10 b, 11 a, 11 b) with higher oxidation state at C14 were isolated as well.…”