(1R,2'R,4S,5'S,6'R,8R,10E,12S,13S,14Z,20R,21R,24S)-12-{[(2R,4S,5S,6S)-5-{[(2S,4S,5S,6S)-5-hydroxy-4-methoxy-6-methyl-3,4,5,6-tetrahydro-2H-pyran-2-yl]oxy}-4-methoxy-6-methyl-3,4,5,6-tetrahydro-2H-pyran-2-yl]oxy}-6'-[(2S)-but-2-yl]-21,24-dihydroxy-5',11,13,22-tetramethyl-3',4',5',6'-tetrahydrospiro[3,7,19-trioxatetracyclo[18.3.1.14,8.017,24]pentacosa-10,14,16,22-tetraene-6,2'-pyran]-2,18-dione