(1S,2'R,4R,5'S,6'S,7S,9S,10E,12E,14R,16E,19R)-7,9-dihydroxy-4'-[(E)-methoxyazanylidene]-5',6,10,14,16-pentamethyl-6'-[(2E)-4-methylpent-2-en-2-yl]-3',4',5',6'-tetrahydrospiro[2,20-dioxatricyclo[17.3.1.04,9]tricosa-5,10,12,16-tetraene-21,2'-pyran]-3-one