(1S,2R,3′R,4′R,5R,7R,8E,10E,12S,15S,17R,20R,21S,25R,28S,29S,30R,33R,34R,36S)-3′,29-Dihydroxy-4′,5,7,9,20,30,36-heptamethyl-3′,4′,5′,6′-tetrahydro-19H,32H-spiro[13,18,39,40,41,42,43,44,45-nonaoxanonacy clo[32.4.1.1~1,36~.1~2,5~.1~12,15~.1~21,25~.1~25,28~.1~30,33~.0~12,17~]pentatetraconta-8,10-diene-14,2′-pyran]-19,32-dione