139594-87-9 3,26,27-Trioxatricyclo(21.2.1.16,9)heptacos-13-ene-4,18,21-trione, 10,11,16-trihydroxy-7,14,15,19-tetramethyl-12-methylene-2-(4-methyl-1,3-pentadienyl)- Amphidinolide F