11,12-Bis(acetyloxy)-5,6,7-trihydroxy-1,5,5a,11a,13a-pentamethyl-4,8-dioxo-4,5,5a,5b,6,6a,6b,7,8,8a,9,9a,10a,11,11a,11b,12,13,13a,13b-icosahydro-1H-oxireno[2'',3'':6',7']naphtho[1',2':7,8]fluoreno[2,1\t-b]furan-13-yl acetate AIDS-132709 AIDS132709 NSC627262 Taccalonolide B